No Evidence That Extreme Weather on the Rise: A Look at the Past - (3) Floods

Devastating 2022 floods in Pakistan that affected 33 million people and damaged or destroyed over 2 million homes. A 2021 once-in-a-millennium flood in Zhengzhou, China that drowned passengers in a subway tunnel. Both events were trumpeted by the mainstream media as unmistakable signs that climate change has intensified the occurrence of weather extremes such as major floods, droughts, hurricanes, tornadoes and heat waves.

But a close look at history shows that it’s the popular narrative that is mistaken. Just as with hurricanes and tornadoes, floods today are no more common nor deadly or disruptive than any of the thousands of floods in the past, despite heavier precipitation in a warming world.

Floods tend to kill more people than hurricanes or tornadoes, either by drowning or from subsequent famine, although part of the death toll from landfalling hurricanes is often drownings caused by the associated storm surge. Many of the world’s countries regularly experience flooding, but the most notable on a recurring basis are China, India, Pakistan and Japan.

China has a long history of major floods going back to the 19th century and before. One of the worst was the flooding of the Yangtze and other rivers in 1931 that inundated approximately 180,000 square kilometers (69,500 square miles) following rainfall in July of over 610 mm (24 inches). That was a far greater area flooded than the 85,000 square kilometers (33,000 square miles) underwater in Pakistan’s terrible floods last year, and affected far more people – as many as 53 million.

The extent of the watery invasion can be seen in the top two photos of the montage on the left; the bottom photo displays the havoc wrought in the city of Wuhan. A catastrophic dike failure near Wuhan left almost 800,000 people homeless and covered the city with several meters of water for months.

Chinese historians estimate the countrywide death toll at 422,000 from drowning alone; an additional 2 million people reportedly died from starvation or disease resulting from the floods, and much of the population was reduced to “eating tree bark, weeds, and earth.” Some sold their children to survive, while others resorted to cannibalism.

 The disaster was widely reported. The Evening Independent wrote in August 1931:

Chinese reports … indicate that the flood is the greatest catastrophe the country has ever faced.

The same month, the Pittsburgh Post-Gazette, an extract from which is shown in the figure below, recorded how a United News correspondent witnessed:

thousands of starving and exhausted persons sitting motionless on roofs or in shallow water, calmly awaiting death.

The Yangtze River flooded again in 1935, killing 145,000 and leaving 3.6 million homeless, and also in 1954 when 30,000 lost their lives, as well as more recently. Several other Chinese rivers also flood regularly, especially in Sichuan province.

The Pakistan floods of 2022 are the nation’s sixth since 1950 to kill over 1,000 people. Major floods afflicted the country in 1950, 1955, 1956, 1957, 1959, throughout the 1970s, and in more recent years. Typical flood scenes are shown in the photos below, together with a New York Times report of a major flood in 1973.

Monsoonal rains in 1950 led to flooding that killed an estimated 2,900 people across the country and caused the Ravi River in northeastern Pakistan to burst its banks; 10,000 villages were decimated and 900,000 people made homeless.

In 1973, one of Pakistan’s worst-ever floods followed intense rainfall of 325 mm (13 inches) in Punjab (which means five rivers) province, affecting more than 4.8 million people. The Indus River – of which the Ravi River is a tributary – became a swollen, raging torrent 32 km (20 miles) wide, sweeping 300,000 houses and 70,000 cattle away. 474 people perished.

In an area heavily dependent on agriculture, 4.3 million bales of the cotton crop and hundreds of millions of dollars worth of stored wheat were lost. Villagers had to venture into floodwaters to cut fodder from the drowned and ruined crops in order to feed their livestock. Another article on the 1973 flood in the New York Times reported the plight of flood refugees:

In Sind, many farmers, peasants and shopkeepers fled to a hilltop railway station where they climbed onto trains for Karachi.

Monsoon rainfall of 580 mm (23 inches) just three years later in July and September of 1976, again mostly in Punjab province, caused a flood that killed 425 and affected another 1.7 million people. It’s worth noting here that the 1976 deluge far exceeded the 375 mm (15 inches) of rain preceding the massive 2022 flood, although both inundated approximately the same area. The 1976 flood affected a total of 18,400 villages.

A shorter yet deadly flood struck the coastal metropolis of Karachi the following year in 1977, after 210 mm (8 inches) of rain fell on the city in 12 hours. Despite its brief duration, the flood drowned 848 people and left 20,000 homeless. That same year, the onslaught of floods in the country prompted the establishment of a Federal Flood Commission.

The figure below shows the annual number of flood fatalities in Pakistan from 1950 to 2012, which includes drownings from cyclones as well as monsoonal rains.

Many other past major floods, in India, Japan, Europe and other countries, are recorded in the history books, all just as devastating as more recent ones such as those in Pakistan or British Columbia, Canada. Despite the media’s neglect of history, floods are not any worse today than before.

Next: No Evidence That Extreme Weather on the Rise: A Look at the Past - (4) Droughts

No Evidence That Extreme Weather on the Rise: A Look at the Past - (2) Tornadoes

After a flurry of tornadoes swarmed the central U.S. this March, the media were quick to fall into the trap of linking the surge to climate change, as often occurs with other forms of extreme weather. But there is no evidence that climate change is causing tornadoes to become more frequent and stronger, any more than hurricanes are increasing in strength and number, as I discussed in my previous post.

Indeed, there are ample examples of past tornadoes just as or more violent and deadly than today’s, but conveniently ignored by believers in the narrative that weather extremes are on the rise.

Like hurricanes, tornadoes are categorized according to wind speed, using the Fujita Scale going from EF0 to EF5 (F0 to F5 before 2007); EF5 tornadoes attain wind speeds up to 480 km per hour (300 mph). More terrifying than hurricanes because they often arrive without warning, tornadoes also have the awesome ability to hurl cars, struc­tural debris, animals and even people through the air.

In the U.S., tornadoes cause about 80 deaths and more than 1500 injuries per year. The deadliest  episode of all time in a sin­gle day was the “tri-state” outbreak in 1925, which killed over 700 peo­ple and resulted in the most damage from any tornado outbreak in U.S. history. The photo montage on the right shows one of the 12 or more tornadoes observed in Missouri, Illinois and Indiana approaching a farm (top); some of the 154 city blocks obliterated in Murphysboro, Illinois (middle); and the wreckage of Murphysboro’s Longfellow School, where 17 children were killed (bottom).                                                                                     Unlike the narrow path of most tornadoes, the swath of destruction wrought by the main F5 tornado was up to 2.4 km (1.5 miles) wide. Amazingly, the ferocious storm persisted for a distance of 353 km (219 miles) in its 3 ½-hour lifetime. Together with smaller F2, F3 and F4 tornadoes, the F5 tri-state tornado destroyed or almost destroyed numerous towns. Another 33 schoolchildren died in De Soto, Illinois when their school collapsed. De Soto’s deputy sheriff was sucked into the funnel cloud, never to be seen again.

Newspapers of the day chronicled the devastation. United Press described how:

a populous, prosperous stretch of farms, villages and towns … suddenly turned into an inferno of destruction, fire, torture and death.

The Ellensburg Daily Record reported that bodies were carried as far as a mile by the force of the main tornado.

Over three successive days in May 1953, at least 10 different U.S. states were struck by an outbreak of more than 33 tornadoes, the deadliest being an F5 tornado that carved a path directly though the downtown area of Waco, Texas (photo immediately below). Believing falsely that their city was immune to tornadoes, officials had not insisted on construction of sturdy buildings, many of which collapsed almost immediately and buried their occupants.

The same day, a powerful F4 tornado hit the Texas city of San Angelo, causing catastrophic damage. As mentioned in the accompanying newspaper article below, an American Associated Press correspondent reported “a scene of grotesque horror” in Waco and described how San Angelo’s business area was “strewn with kindling wood.”

June that year saw a sequence of powerful tornadoes wreak havoc across the Midwest and New England, the latter being well outside so-called Tornado Alley. An F5 tornado in Flint, Michigan (upper photo in figure below) and an F4 tornado in Worcester, Massachusetts (lower photo) each caused at least 90 deaths and extensive damage. The accompanying newspaper article, in Australia’s Brisbane Courier-Mail, mentions how cars were “whisked about like toys.”

Nature’s wrath was on display again in the most ferocious tornado outbreak ever recorded, spawning a total of 30 F4 or F5 tornadoes – the so-called Super Outbreak – in April 1974. A total of 148 tornadoes of all strengths struck 13 states in Tornado Alley and the Canadian province of Ontario over two days; their distribution and approximate path lengths are depicted in the left panel of the next figure.

The photos on the right illustrate the massive F5 tornado, the worst of the 148, that bore down on Xenia, Ohio (population 29,000, top) and the resulting damage (middle and bottom). The Xenia tornado was so powerful that it tossed freight trains on their side, and even dropped a school bus onto a stage where students had been practicing just moments before. Wrote the Cincinatti Post of the devastation:

Half of Xenia is gone.

In Alabama, two F5 tornadoes, out of 75 that struck the state, hit the town of Tanner within 30 minutes; numerous homes, both brick and mobile, were chewed up or swept away. In Louisville, Kentucky, battered by an F4 tornado, a Navy veteran who lost his home lamented in the Louisville Times that:

only Pearl Harbor was worse.

In all, the Super Outbreak caused 335 fatalities and over 6,000 injuries.

The following figure shows that the annual number of strong tornadoes (EF3 or greater) in the U.S. has declined dramatically over the last 72 years. In fact, the average number of strong tor­nadoes annually from 1986 to 2017 – a period when the globe warmed by about 0.7 degrees Celsius (1.3 degrees Fahrenheit) – was 40% less than from 1954 to 1985, when warming was much less. That turns the extreme weather caused by climate change narrative on its head.

Hat tip: Tony Heller @TonyClimate, who discovered the two newspaper articles above.

Next: No Evidence That Extreme Weather on the Rise: A Look at the Past - (3) Floods

No Evidence That Extreme Weather on the Rise: A Look at the Past - (1) Hurricanes

The popular but mistaken belief that today’s weather extremes are more common and more intense because of climate change is becoming deeply embedded in the public consciousness, thanks to a steady drumbeat of articles in the mainstream media and pronouncements by luminaries such as President Biden in the U.S., Pope Francis and the UN Secretary-General.

But the belief is wrong and more a perception than reality. An abundance of scientific evidence demonstrates that the frequency and severity of floods, droughts, hurricanes, tornadoes, heat waves and wildfires are not increasing, and may even be declining in some cases. That so many people think otherwise reflects an ignorance of, or an unwillingness to look at, our past climate. Collective memories of extreme weather are short-lived.  

In this and subsequent posts, I’ll present examples of extreme weather over the past century or so that matched or exceeded anything we’re experiencing in the present-day world. I’ll start with hurricanes.

The deadliest U.S. hurricane in record­ed history struck Galveston, Texas in 1900, killing an estimated 8,000 to 12,000 people. Lacking a protective seawall built later, the thriving port was completely flattened (photo on right) by winds of 225 km per hour (140 mph) and a storm surge exceeding 4.6 meters (15 feet). With almost no automobiles, the hapless populace could flee only on foot or by horse and buggy. Reported the Nevada Daily Mail at the time:

Residents [were] crushed to death in crumbling buildings or drowned in the angry waters.

Hurricanes have been a fact of life for Americans in and around the Gulf of Mexico since Galveston and before. The death toll has come down over time with improvements in planning and engineering to safeguard structures, and the development of early warning sys­tems to allow evacuation of threatened communities.

Nevertheless, the frequency of North Atlantic hurricanes has been essentially unchanged since 1851, as seen in the following figure. The apparent heightened hurricane ac­tivity over the last 20 years, particularly in 2005 and 2020, simply reflects improvements in observational capabilities since 1970 and is unlikely to be a true climate trend, say a team of hurricane experts.

As you can see, the incidence of major North Atlantic hurricanes in recent decades is no higher than that in the 1950s and 1960s. Ironically, the earth was actually cooling during that period, unlike today.

Of notable hurricanes during the active 1950s and 1960s, the deadliest was 1963’s Hurricane Flora that cost nearly as many lives as the Galveston Hurricane. Flora didn’t strike the U.S. but made successive landfalls in Tobago, Haiti and Cuba (path shown in photo on left), reaching peak wind speeds of 320 km per hour (200 mph). In Haiti a record 1,450 mm (57 inches) of rain fell – comparable to what Hurricane Harvey dumped on Houston in 2017 – resulting in landslides which buried whole towns and destroyed crops. Even heavier rain, up to 2,550 mm (100 inches), devastated Cuba and 50,000 people were evacuated from the island, according to the Sydney Morning Herald.

Hurricane Diane in 1955 walloped the North Carolina coast, then moved north through Virginia and Pennsylvania before ending its life as a tropical storm off the coast of New England. Although its winds had dropped from 190 km per hour (120 mph) to less than 55 km per hour (35 mph) by then, it spawned rainfall of 50 cm (20 inches) over a two-day period there, causing massive flooding and dam failures (photo to right). An estimated total of 200 people died. In North Carolina, Diane was but one of three hurricanes that struck the coast in just two successive months that year.

In 1960, Hurricane Donna moved through Florida with peak wind speeds of 285 km per hour (175 mph) after pummeling the Bahamas and Puerto Rico. A storm surge of up to 4 meters (13 feet) combined with heavy rainfall caused extensive flooding all across the peninsula (photo on left). On leaving Florida, Donna struck North Carolina, still as a Category 3 hurricane (top wind speed 180 km per hour or 110 mph), and finally Long Island and New England. NOAA (the U.S. National Oceanic and Atmospheric Administration) calls Donna “one of the all-time great hurricanes.”

Florida has been a favorite target of hurricanes for more than a century. The next figure depicts the frequency by decade of all Florida landfalling hurricanes and major hurricanes (Category 3, 4 or 5) since the 1850s. While major Florida hurricanes show no trend over 170 years, the trend in hurricanes overall is downward – even in a warming world.

Hurricane Camille in 1969 first made landfall in Cuba, leaving 20,000 people homeless. It then picked up speed, smashing into Mississippi as a Category 5 hurricane with wind speeds of approximately 300 km per hour (185 mph); the exact speed is unknown because the hurricane’s impact destroyed all measuring instruments. Camille generated waves in the Gulf of Mexico over 21 meters (70 feet) high, beaching two ships (photo on right), and caused the Mississippi River to flow backwards. A total of 257 people lost their lives, the Montreal Gazette reporting that workers found:

a ton of bodies … in trees, under roofs, in bushes, everywhere.

These are just a handful of hurricanes from our past, all as massive and deadly as last year’s Category 5 Hurricane Ian which deluged Florida with a storm surge as high as Galveston’s and rainfall up to 685 mm (27 inches); 156 were killed. Hurricanes are not on the rise today.

Next: No Evidence That Extreme Weather on the Rise: A Look at the Past - (2) Tornadoes

Challenges to the CO2 Global Warming Hypothesis: (8) The Antarctic Centennial Oscillation as the Source of Global Warming

Possibly overlooked at the time it was published, a 2018 paper on Antarctica presents an unusual challenge to the CO₂ global warming hypothesis, which postulates that observed global warming – currently about 0.9 degrees Celsius (1.6 degrees Fahrenheit) since the preindustrial era – has been caused primarily by human emissions of CO₂ and other greenhouse gases into the atmosphere.

The proposed challenge is that current global warming can be explained by a natural ocean cycle known as the ACO (Antarctic Centennial Oscillation), the evolutionary precursor of today’s AAO (Antarctic Oscillation), also called the SAM (Southern Annular Mode). This unconventional idea comes from a group of researchers at the Environmental Studies Institute in Santa Cruz, California.

The Santa Cruz group points out that global temperatures have oscillated for at least the last 542 million years, since the beginning of the current Phanerozoic Eon. Superimposed on multi-millennial climate cycles are numerous shorter global and regional cycles ranging in period from millennia down to a few weeks. Among these are numerous present-day ocean cycles, including the above AAO, ENSO (the El Niño – Southern Oscillation) and the AMO (Atlantic Multidecadal Oscillation).

In their 2018 paper the researchers report on the previously unexplored ACO, the record of which is entrained in stable isotopes frozen in ice cores at Vostok in Antarctica and three additional Antarctic drill sites widely distributed on the East Antarctic Plateau, namely, EPICA (European Project for Ice Coring in Antarctica) Dronning Maud Land, EPICA Dome C and Talos Dome.

Past surface temperatures were calculated from the ice cores by measuring either the oxygen ¹⁸O to ¹⁶O, or hydrogen ²H to ¹H, isotopic ratios. Precise ice-core chronology enabled the paleoclimate records from the four drill sites to be synchronized in time.

In analyzing the ice-core data, the paper’s authors found a prominent cycle with a mean repetition period of 352 years over the time interval they evaluated, from 226,400 years before 1950 to the year 1801. Identified as the ACO, the cycle time series nevertheless shows a progressive increase in both frequency and amplitude or temperature swing, the period shortening as the amplitude increases proportionally.

The figure below illustrates the cycle’s temperature oscillations, as measured at Vostok for the last 20,000 years. LGM is the Last Glacial Maximum, LGT the subsequent Last Glacial Termination, and the time scale is measured in thousands of years before 1950 (Kyb1950). The top panel shows temperatures from the LGM to the present, while the lower four panels show the record on an expanded time and temperature scale, with every identified ACO cycle labeled. The small blue and red numbers designate smaller-amplitude oscillations (approximately 10% of all cycles identified), which were found at all four drill sites.

The steady decline of the ACO period over 226 millennia, and the corresponding rise in temperature swing, are depicted in the next figure for the Vostok record. Here individual records have been averaged over 5,000-year intervals. Without averaging, the period ranges from 63 to 1,174 years, and the cycle temperature swing varies from 0.05 degrees Celsius (0.09 degrees Fahrenheit) to as much as 3.2 degrees Celsius (5.8 degrees Fahrenheit).

Because of the variation in period (frequency) and amplitude, the null hypothesis that the observed cycles represent random fluctuations in cycle structure was tested by the researchers, using the statistical concept of autocorrelation. This confirmed that the cycle structure was indeed nonrandom. However, the data for the whole 226,400 years did reveal evidence for other, lower-frequency cycles, including ones with periods of 1,096 and 1,470 years.

So how is all this connected to global warming?

The variable ACO cycles show that temperature fluctuations of several degrees Celsius have occurred many times in the past 226 millennia, including our present Holocene (c and d in the first figure above) – at least in Antarctica. That these Antarctic cycles extend globally was inferred by the researchers from the correspondence between the 1,096- and 1,470-year ACO cycles mentioned above and so-called Bond events in the Northern Hemisphere, which are thought to have the same periodicity but occur up to 3 millennia later.

Bond events refer to glacial debris rafted into the North Atlantic Ocean by icebergs and then dropped onto the sea floor as the icebergs melt.  The volume of glacial debris, which is measured in deep-sea sediment cores, fluctuates as global temperatures rise and fall.

1,096 and 1,470 years are also approximate multiples of the mean ACO period of 352 years. This finding, together with the observation about Bond events, is considered by the researchers to be strong evidence that the ACO is a natural climate cycle that arises in Antarctica and then propagates northward, influencing global temperatures. It’s feasible that our current global warming – during which temperatures have already risen by close to 1 degree Celsius (1.8 degrees Fahrenheit) – is simply part of the latest ACO (or AAO/SAM) cycle.

Such speculation, however, needs to be reinforced by solid scientific evidence before it can be considered a serious challenge to the CO₂ hypothesis.

Next: No Evidence That Extreme Weather on the Rise: A Look at the Past - (1) Hurricanes

CRED’s “2022 Disasters in Numbers” Report Is a Disaster in Itself

The newly released 2022 annual disasters report from the highly acclaimed international agency, CRED (Centre for Research on the Epidemiology of Disasters), is even more dishonest than its 2021 report which I reviewed in a previous post. The 2022 report contains numerous statements that cannot be justified by the evidence, and demonstrates a misunderstanding of basic statistics which is puzzling for an organization that collects and analyzes data.

The most egregious statements involve the death toll from weather-related disasters. In one section of the report, CRED cites the well-known fact that mortality from natural disasters is 98% lower today than a century earlier. Although this is actually based on CRED’s EM-DAT (Emergency Events Database), the 2022 report gripes that “A more careful examination of mortality statistics indicates that this percentage may be misleading. Misinterpreting statistics could be harmful if it supports a discourse minimizing the importance of climate action.”

Laughably, it is CRED’s new report that is misleading and misinterprets statistics. This is evident from the following two figures from the report and the accompanying commentary. Figure A shows the global annual number of deaths per decade from natural disasters between 1900 and 2020, compiled from 12,223 records in the EM-DAT da­tabase, while the highly misleading Figure B shows the same data excluding the 50 deadliest disasters.

In Figure A, it is clear that disaster-related deaths have been falling since the 1920s and are now approaching zero. Nevertheless, the 2022 CRED report makes the weak argument that if the 1910s were taken as the comparison baseline instead of the 1920s, the 98% fall would be only 30%. But a close look at the data reveals a total of 1.27 million deaths recorded in the year 1900, yet almost none at all from 1901 to 1919 (less than 50,000 in most years) – suggesting some deficiency in data collection during that period.

However, far more blatant is the report’s manipulation of the data in Figure A, by removing the 50 deadliest disasters from the dataset and then claiming that disaster deaths show “a positive mortality trend” over the last century, as depicted in Figure B.

Such subterfuge is both dishonest and statistically flawed. Some disasters are more deadly, some less; the only way to present any trend honestly is to include all the data. A fundamental tenet of the scientific method is that you can’t ignore any piece of evidence that doesn’t fit your narrative, simply because it’s inconvenient. And statistically, a disaster trend is a disaster trend, regardless of the disaster magnitude. If anything, the deadliest disasters – not the least deadly, as plotted in Figure B – carry the most weight in illustrating any trend in deaths.

While CRED sheepishly admits that Figure B “does not necessarily mean that we now have firm evidence that disaster-related mortality is increasing,” it gives away its true motive in presenting the figure by musing whether the fictitious positive trend is “supported by other drivers, e.g., population growth in exposed areas and climate change.”

The report goes on to argue that the main trend observed in Figure A is a result of five drought-induced famines, which each caused more than one million deaths from the 1920s to the 1960s. This statement is also deceptive, as can be seen from the figure below. The figure is similar to CRED’s Figure A and based on the same EM-DAT database, but breaks down the number of people killed in each decade into disaster category and corrects for population increase over time; the same data uncorrected for population increase show exactly the same features.

You can see that deaths from drought were dominant in the 1900s, 1920s, 1940s, 1960s and 1980s, but not the 1910s, 1930s, 1950s and 1970s. So CRED’s argument that the strong downward trend in Figure A is due to a large number of drought-induced famine deaths between 1920 and 1970 is nonsense.

Another section of the CRED report presents disaster death data for 2022, which is summarized in the following figure from the report. CRED comments that “the total death toll of 30,704 in 2022 was three times higher than in 2021 but below the 2002-2021 average of 60,955 deaths,” both of which are correct statements. However, the report then goes on to claim that the relatively high 2002-2021 average is “influenced by a few mega-disasters” and that “a more useful comparison [is that] the 2022 toll is almost twice the 2002-2021 median of 16,011 deaths.”

Again, these are meaningless comparisons that demonstrate an ignorance of statistics. The individual yearly death totals are unrelated – independent events in the language of statistics – so assigning any statistical significance to the 30,704 deaths in 2022 being lower than the long-term average, or higher than the long-term median, is invalid. CRED’s attempt to fit its data to a narrative emphasizing “the importance of climate action” falls flat.

The statistical inadequacies of CRED’s comparisons are also made clear by examining the recent trend in CRED’s EM-DAT data. The next figure shows the yearly number of climate-related disasters globally from 2000 through 2022 by major category. The disasters are those in the climatological (droughts, glacial lake outbursts and wildfires), meteorological (storms, extreme temperatures and fog), and hydrological (floods, landslides and wave action) categories.

As can be seen, the total number of climate-related disasters exhibits a slowly declining trend since 2000 (red line), falling by 4% over 23 years.

Next: Challenges to the CO2 Global Warming Hypothesis: (8) The Antarctic Centennial Oscillation as the Source of Global Warming

Global Warming from Food Production and Consumption Grossly Overestimated

A recent peer-reviewed study makes the outrageous claim that production and consumption of food could contribute as much as 0.9 degrees Celsius (1.6 degrees Fahrenheit) to global warming by 2100, from emissions of the greenhouse gases methane (CH₄), nitrous oxide (N₂O) and carbon dioxide (CO₂).

Such a preposterous notion is blatantly wrong, even if it were true that global warming largely comes from human CO₂ emissions. Since agriculture is considered responsible for an estimated 15-20% of current warming, a 0.9 degrees Celsius (1.6 degrees Fahrenheit) agricultural contribution in 2100 implies a total warming (since 1850-1900) at that time of 0.9 / (0.15–0.2), or 4.5 to 6.0 degrees Celsius (8.1 to 10.8 degrees Fahrenheit).

As I discussed in a previous post, only the highest, unrealistic CO₂ emissions scenarios project such a hot planet by the end of the century. A group of prominent climate scientists has estimated the much lower range of likely 2100 warming, of 2.6-3.9 degrees Celsius (4.7-7.0 degrees Fahrenheit). And climate writer Roger Pielke Jr. has pegged the likely warming range at 2-3 degrees Celsius (3.6-5.4 degrees Fahrenheit), based on the most plausible emissions scenarios.

Using the same 15-20% estimate for the agricultural portion of global warming, a projected 2100 warming of say 3 degrees Celsius (5.4 degrees Fahrenheit) would mean a contribution from food production of only 0.45-0.6 degrees Celsius (0.8-1.1 degrees Fahrenheit) – about half of what the new study’s authors calculate.

That even this estimate of future warming from agriculture is too high can be seen by examining the following figure from their study. The figure illustrates the purported temperature rise by 2100 attributable to each of the three greenhouse gases generated by the agricultural industry: CH₄, N₂O and CO₂. CH₄ is responsible for nearly 60% of the temperature increase, while N₂O and CO₂ each contribute about 20%.

This figure can be compared with the one below from a recent preprint by a team which includes atmospheric physicists William Happer and William van Wijngaarden, showing the authors’ evaluation of expected radiative forcings at the top of the troposphere over the next 50 years. The forcings are increments relative to today, measured in watts per square meter; the horizontal lines are the projected temperature increases (ΔT) corresponding to particular values of the forcing increase.

To properly compare the two figures, we need to know what percentages of total CH₄, N₂O and CO₂ emissions in the Happer and van Wijngaarden figure come from the agricultural sector; these are approximately 50%, 67% and 3%, respectively, according to the authors of the food production study.

Using these percentages and extrapolating the Happer and van Wijngaarden graph to 78 years (from 2022), the total additional forcing from the three gases in 2100 can be shown to be about 0.52 watts per square meter. This forcing value corresponds to a temperature increase due to food production and consumption of only around 0.1 degrees Celsius (0.18 degrees Fahrenheit).

The excessively high estimate of 0.9 degrees Celsius (1.6 degrees Fahrenheit) in the study may be due in part to the study’s dependence on a climate model: many climate models greatly exaggerate future warming.

While on the topic of CH₄ and N₂O emissions, let me draw your attention to a fallacy widely propagated in the climate science literature; the fallacy appears on the websites of both the U.S. EPA (Environmental Protection Agency) and NOAA (the U.S. National Oceanic and Atmospheric Administration), and even in the IPCC’s Sixth Assessment Report (Table 7.15).

The fallacy conflates the so-called “global warming potential” for greenhouse gas emissions, which measures the warming potential per molecule (or unit mass) of various gases, with their warming potential weighted by their rate of concentration increase relative to CO₂. Because the abundances of CH₄ and N₂O in the atmosphere are much lower than that of CO₂, and are increasing even more slowly, there is a big difference between their global warming potentials and their weighted warming potentials.

The difference is illustrated in the table below. The conventional global warming potential (GWP) is a dimensionless metric, in which the GWP of a particular greenhouse gas is normalized to that of CO₂; the GWP takes into account the atmospheric lifetime of the gas. The table shows values of GWP-100, the warming potential calculated over a 100-year time horizon.

The final column shows the value of the weighted GWP-100, which is not dimensionless like the conventional GWP-100 but measured in units of watts per square meter, the same as radiative forcing. The weighted GWP-100 is calculated by multiplying the conventional GWP-100 by the ratio of the rate of concentration increase for that gas to that of CO₂.

As you can see, the actual anticipated warming in 100 years from either CH₄ or N₂O agricultural emissions will be only 10% of that from CO₂ – in contrast to the conventional GWP-100 values extensively cited in the literature. What a waste of time and effort in trying to rein in CH₄ and N₂O emissions!

Next: CRED’s 2022 Disasters in Numbers report is a Disaster in Itself

No Evidence That Cold Extremes Are Becoming Less Frequent

The IPCC (Intergovernmental Panel on Climate Change), whose assessment reports are the voice of authority for climate science, errs badly in its Sixth Assessment Report (AR6) by claiming that cold weather extremes have become less frequent and severe. While that may be expected in a warming world, observational evidence shows that in fact, cold extremes are on the rise and may actually have become more severe.

Cold extremes include abnormally low temperatures, prolonged cold spells, unusually heavy snowfalls and longer winter sea­sons. That cold extremes are indeed increasing has been chronicled in detail by environmental scientist Madhav Khandekar in several recent research papers (here, here and here). While the emphasis of Khandekar’s publications has been on harsh winters in North America, he has catalogued cold extremes in South America, Europe and Asia as well.

The figure below shows the locations of 4,145 daily low-temperature records broken or tied in the northeastern U.S. during the ice-cold February of 2015; that year tied with 1904 for the coldest Janu­ary to March period in the northeast, in records extending back to 1895. Of the 4,145 records, 3,573 were new record lows and the other 572 tied previous records.

Examples of cold extremes in recent years abound (see here and here). During the 2020 southern winter and northern summer, the Australian island state of Tasmania recorded its most frigid winter minimum ever, exceeding the previous low of −13.0 degrees Celsius (8.6 degrees Fahrenheit) by 1.2 degrees Celsius (2.2 degrees Fahrenheit); Norway endured its chilliest July in 50 years; neighboring Sweden shivered through its coldest sum­mer since 1962; and Russia was also bone-chilling cold.

In the northern autumn of 2020, bitterly cold temperatures afflicted many communities in the U.S. and Canada. The north­ern U.S state of Minnesota experienced its largest early-season snowstorm in recorded history, going back about 140 years. And in late December, the subfreezing polar vortex began to expand out of the Arctic.

Earlier in 2020, massive snowstorms covered much of Patagonia in more than 150 cm (60 inches) of snow, and buried alive at least 100,000 sheep and 5,000 cattle. Snowfalls not seen for decades occurred in other parts of South America, and in South Africa, southeastern Australia and New Zealand.

A 2021 example of a cold extreme was the North American cold wave in February, which brought record-breaking subfreez­ing temperatures to much of the central U.S., as well as Canada and northern Mexico. Texas experienced its coldest February in 43 years; the frigid conditions lasted several days and resulted in widespread power outages and damage to infrastructure. Curiously, the Texan deep freeze was ascribed to global warming by a team of climate scien­tists, who linked it to stretching of the Arctic polar vortex.

Other exceptional cold extremes in 2021 included the lowest average UK minimum temperature for April since 1922; record low temperatures in both Switzerland and Slove­nia the same month; the coldest winter on record at the South Pole; and an all-time high April snowfall in Belgrade, in record books dating back to 1888.

In 2022, Australia and South America saw some of their coldest weather in a century. In May, Australia experienced the heaviest early-season mountain snow in more than 50 years. In June, Brisbane in normally temperate Queensland had its coldest start to winter since 1904. And in December, the state of Victoria set its coldest summer temperature record ever.

South America also suffered icy conditions in 2022, after an historically cold winter in 2021 which decimated crops. The same Antarctic cold front that froze Australia in May brought bone-numbing cold to northern Argentina, Paraguay and southern Brazil; Brazil’s capital Brasilia logged its lowest temperature in recorded history.

In December 2022, the U.S. set 126 monthly low-temperature records, while century-old low-temperature records tumbled in neighboring Canada. This followed all-time record-breaking snow in Japan, extra-heavy snow in the Himalayas which thwarted mountain climbers there, and heavy snow across China and South Korea.

Clearly, cold extremes are not going away or becoming less severe. And frequent statements by the mainstream media linking cold extremes to global warming are absurd, although such statements may fit the popular belief that global warming causes weather extremes in general. As I have explained in numerous blog posts and reports, this belief is mistaken and there is no evidence that weather extremes are worsening because of climate change.

Extreme weather conditions are produced by natural patterns in the climate system, not global warming. Khandekar links cold extremes to the North Atlantic and Pacific Decadal Oscil­lations, and possibly to solar activity.

Next: Global Warming from Food Production and Consumption Grossly Overestimated

Science on the Attack: The James Webb Telescope and Mysteries of the Universe

As another in my series of occasional posts showcasing science on the attack rather than under attack, this post features the James Webb Space Telescope (JWST). This state-of-the-art, massive human eyepiece was launched on Christmas Day, 2021 and is designed to probe the universe, especially the very early universe, at infrared wavelengths.

Approximately the length and weight of a school bus, the reflecting telescope has a primary mirror for light collection comprising 18 hexagonal segments made from gold-plated beryllium, which combine to form a mirror 6.5 meters (21 feet) in diameter. In comparison, the mirror of the earlier Hubble Space Telescope was only 2.4 meters (8 feet) across. Gold plating was chosen for the JWST’s mirror because it reflects up to 99% of infrared light and resists corrosion.

Unlike the Hubble, which orbits the earth at an altitude of 540 km (340 miles), the JWST is in a solar orbit, at a distance from the earth that varies from 250 to 830 thousand km (160 to 520 thousand miles). Circling around the so-called sun–earth L₂ Lagrange point, the telescope orbits the sun in synchrony with the earth.

The size of the JWST’s mirror allows it to see celestial objects 100 times fainter than Hubble can, as well as cosmological events much closer in time to the Big Bang, the cataclysmic explosion thought to have been the birth of the universe 13.7 billion years ago. Objects and events are captured by four cleverly designed infrared cameras and spectrometers.   

Shortly after the JWST began scouring the heavens, cosmologists – who are not known for outbursts of emotion – became wildly excited by a totally unexpected finding amidst the breathtaking images streaming back from the new instrument. The telescope had detected very bright galaxies at the farthest distances it is capable of seeing, distances that correspond to light from a very young universe, only a few hundred million years after the Big Bang.

The puzzle wasn’t that the galaxies are there, but that they are much more massive than the so-called standard model of cosmology predicts. The model, based in part on Einstein’s theory of relativity, is well tested and fits a large number of astronomical observations of the universe. So this head-scratching observation had some cosmologists in a state of panic, wondering if the long-established standard model had to be thrown on the scrap heap.

There are, after all, several other predictions of the standard model for which no observational evidence exists to date – remember that empirical evidence is one of the pillars of science. Primary among these predictions are the somewhat weird concepts of dark matter and dark energy.

According to the standard model, the universe was created from pure energy in the Big Bang and now consists of only 5% ordinary matter (everything we can see, including ourselves, planets, stars and gas clouds), 27% dark matter and 68% dark energy. That’s right, 95% of the universe is invisible!

The need for dark matter, which may include black holes, is inferred from the existence of galaxies: without unseen mass to provide extra gravity, galaxies would fly apart. Dark matter is thought to reside mostly in the outer galactic reaches. Likewise, the existence of dark energy – associated with mysterious, unknown anti-gravitational forces – is postulated to explain the observed expansion of the universe, which would otherwise contract under gravity.

However, as it turns out, the excitement generated by the JWST last year about gigantic galaxies forming in an infant universe was misplaced, and the standard model of cosmology remains intact. The key was the measurement of distance to these fledgling galaxies.

Cosmic distances are determined by measuring an object’s “redshift.” Due to the Doppler effect, the light spectrum from a receding object is shifted to longer, red wavelengths. The larger the redshift, the greater the distance away. This was discovered in 1929 by astronomer Edwin Hubble, for whom the Hubble Telescope is named. The discovery later led to the modern-day concept of an expanding universe, although Hubble himself favored a static universe model.

The traditional photometric redshift, which relates the distance of an astronomical entity to its brightness, is notoriously unreliable because of effects such as dust surrounding a galaxy. That’s the method that led cosmologists to interpret the first JWST observations as overthrowing the standard model and everything we thought we understood about the universe.

But two teams of astrophysicists (see here and here) put an end to speculation in December, when they described measurements of distance to several of JWST’s early, bright galaxies, utilizing a much more reliable method of determining distance known as spectroscopic redshift.

The teams found four baby galaxies just as distant as the previously identified galaxies, but with much smaller masses. They also concluded that distances to the heavier galaxies seen with the JWST had been overestimated by the photometric redshift method, meaning that those galaxies are actually closer and formed later in the evolution of the universe.  

To resolve whether the standard cosmological model allows the smaller, baby galaxies to have existed close to the cosmic dawn, another group of researchers simulated galaxy formation and compared the simulations to the observations just mentioned. What they discovered is that the appearance of less massive galaxies in the early universe is indeed entirely compatible with the standard model. 

More unexpected and surprising observations from the JWST no doubt await us.

Next: No Evidence That Cold Extremes Are Becoming Less Frequent

Nitrous Oxide No More a Threat for Global Warming than Methane

Nitrous oxide (N₂O), a minor greenhouse gas, has recently come under increasing scrutiny for its supposed global warming potency. But, just as with methane (CH₄, concerns over N₂O emissions stem from a basic misunderstanding of the science. As I discussed in a previous post, CH₄ contributes only one tenth as much to global warming as carbon dioxide (CO₂). N₂O contributes even less.

The misunderstanding has been elucidated in a recent preprint by a group of scientists including atmospheric physicists William Happer and William van Wijngaarden, who together wrote an earlier paper on CH₄. The new paper compares the radiative forcings – disturbances that alter the earth’s climate – of N₂O and CH₄ to that of CO₂.

The largest source of N₂O emissions is agriculture, particularly the application of nitrogenous fertilizers to boost crop production, together with cow manure management. As the world’s population continues to grow, so does the use of fertilizers in soil and the head count of cows. Agriculture accounts for approximately 75% of all N₂O emissions in the U.S., emissions which comprise about 7% of the country’s total greenhouse gas emissions from human activities.

But the same hype surrounding the contribution of CH₄ to climate change extends to N₂O as well. The U.S. EPA (Environmental Protection Agency)’s website, among many others, claims that the impact of N₂O on global warming is a massive 300 times that of CO₂ – surpassing even that of CH₄ at supposedly 25 times CO₂. Happer, van Wijngaarden and their coauthors, however, show that the actual contribution of N₂O is tiny, comparable to that of CH₄.

The authors have calculated the spectrum of cooling outgoing radiation for several greenhouse gases at the top of the atmosphere. A calculated spectrum emphasizing N₂O is shown in the figure below, as a function of wavenumber or spatial frequency. The dark blue curve is the spectrum for an atmosphere with no greenhouse gases at all, while the black curve is the spectrum including all greenhouse gases. Removing the N₂O results in the green curve; the red curve, barely distinguishable from the black curve, represents a doubling of the present N₂O concentration.

The yearly abundance of N₂O in the atmosphere since 1977, as measured by NOAA (the U.S. National Oceanic and Atmospheric Administration), is depicted in the adjacent figure. Currently, the N₂O concentration is about 0.34 ppm (340 ppb), three orders of magnitude lower than the CO₂ level of approximately 415 ppm, and increasing much more slowly – at a rate of 0.85 ppb per year since 1985, 3000 times smaller than the rate of increase of CO₂.

At current atmospheric concentrations of N₂O and CO₂, the radiative forcing for each additional molecule of N₂O is about 230 times larger than that for each additional molecule of CO₂. Importantly, however, because the rate of increase in the N₂O level is 3000 times smaller, the contribution of N₂O to the annual increase in forcing is only 230/3000 or about one thirteenth that of CO₂. For comparison, the contribution of CH₄ is about one tenth the CO₂ contribution.

The relative contributions to future forcing of N₂O, CH₄ and CO₂ can be seen in the next figure, showing the research authors’ evaluation of expected forcings at the top of the troposphere over the next 50 years; the forcings are increments relative to today, measured in watts per square meter. The horizontal lines are the projected temperatures increases (ΔT) corresponding to particular values of the forcing increase.

Atmospheric N₂O dissociates into nitrogen (N₂), the most abundant gas in the atmosphere. N₂ is “fixed” by microrganisms in soils and the oceans as ammonium ions, which are then converted to inorganic nitric oxide ions (NO₃^-) and various compounds. These in turn are incorporated into organic molecules such as amino acids and other nitrogen-containing molecules essential for life, like DNA (deoxyribonucleic acid). Nitrogen is the third most important requirement for plant growth, after water and CO₂.

Greatly increased use of nitrogen fertilizers is the main reason for massive increases in crop yields since 1961, part of the so-called green revolution in agriculture. The following figure shows U.S. crop yields relative to yields in 1866 for corn, wheat, barley, grass hay, oats and rye. The blue dashed curve is the annual agricultural usage of nitrogen fertilizer in megatonnes (Tg). The strong correlation with crop yields is obvious.

While most soil nitrogen is eventually returned to the atmosphere as N₂ molecules, some of the slow increase in the atmospheric N₂O level seen in the second figure above may be due to nitrogen fertilizer usage. But the impact of nitrogen fertilizer and natural nitrogen fixation on the nitrogen cycle is not yet clear and more research is needed.

Nonetheless, proposed cutbacks in fertilizer use will drastically reduce agricultural yields around the world, for the sake of only a tiny reduction in global warming potential.

Next: Science on the Attack: The James Webb Telescope and Mysteries of the Universe

New Observations Upend Notion That Global Warming Diminishes Cloud Cover

Climate scientists have long thought that low clouds, which act like a parasol and cool the earth’s surface, will diminish as the earth heats up – thus amplifying warming in a positive feedback process. This notion has been reinforced by climate models. But recent empirical observations refute the idea and show that the mechanism causing the strongest cloud reductions in models doesn’t actually occur in nature.

The observations were reported in a 2022 paper by an international team of French and German scientists. In a major field campaign, the team collected and analyzed observational data from cumulus clouds near the Atlantic island of Barbados, utilizing two research airplanes and a ship. Barbados is in the tropical trade-wind region where low-level cumulus clouds are common.

More than 800 probes were dropped from one plane that flew in circles about 200 km (120 miles) in diameter at an altitude of 9 km (6 miles); the probes gathered data on atmospheric temperature, moisture, pressure and winds as they fell. The other plane used radar and lidar sensors to measure cloudiness at the base of the cloud layer, at an altitude of 0.8 km (2,600 feet), while the ship conducted surface-based measurements.

The response to global warming of small cumulus clouds in the tropics is critically dependent on how much extra moisture from increased evaporation of seawater accumulates at the base of the clouds.

In climate models, dry air from the upper cloud layer is transported or entrained downward when the clouds grow higher and mixes with the moister air at the cloud base, drying out the lower cloud layer. This causes moisture there to evaporate more rapidly and boosts the probability that the clouds will dissipate. The phenomenon is known to climate scientists as the “mixing-desiccation hypothesis,” the strength of the mixing mechanism increasing with global warming.

But the observations of the research team reveal that the mixing-desiccation mechanism is not actually present in nature. This is because – as the researchers found – mesoscale (up to 200 km) circulation of air vertically upward dominates the smaller-scale entrainment mixing downward. Although mesoscale circulations are ubiquitous in trade-wind regions, their effect on humidity is completely absent from climate models.

The two competing processes are illustrated in the figure below, in which M represents mixing, E is downward entrainment, W is mesoscale vertical air motion, and z is the altitude; the dashed line represents the trade-wind inversion layer.

Predicted by the mixing-desiccation hypothesis is that warming strongly diminishes cloudiness compared with the base state shown in the left panel above. In the base state, vertical air motion is mostly downward and normal convective mixing occurs. According to the hypothesis, stronger mixing (M⁺⁺ in panel a) caused by entrainment (E⁺⁺) of dry air from higher to lower cloud layers, below the cloud base, results in excessive drying and fewer clouds.

The mesoscale circulation mechanism, on the other hand, prevents drying through mesoscale vertical air motion upward (W⁺⁺ in panel b) that overcomes the entrainment mixing, thus preventing cloud loss. If anything, cloud cover actually increases with more vertical mixing. Climate models simulate only the mixing-desiccation mechanism, but the new research demonstrates that a second and more dominant mechanism operates in nature.

That cloudiness increases with mixing can be seen from the next figure, which shows the research team’s observed values of the vertical mixing rate M (in mm per second) and the cloud-base cloudiness (as a percentage). The trend is clear: as M gets larger, so does cloudiness.

The research has important implications for cloud feedback. In climate models, the refuted mixing-desiccation mechanism leads to strong positive cloud feedback – feedback that amplifies global warming. The models find that low clouds would thin out, and many would not form at all, in a hotter world.

Analysis of the new observations, however, shows that climate models with large positive feedbacks are implausible and that a weak trade cumulus feedback is much more likely than a strong one. Climate models with large trade cumulus feedbacks exaggerate the dependence of cloudiness on cloud-base moisture compared with mixing, as well as overestimating variability in cloudiness.

Weaker than expected low cloud feedback is also suggested by lack of the so-called CO₂ “hot spot” in the atmosphere, as I discussed in a previous post. Climate models predict that the warming rate at altitudes of 9 to 12 km (6 to 7 miles) above the tropics should be about twice as large as at ground level. Yet the hot spot doesn’t show up in measurements made by weather balloons or satellites.

Next: Nitrous Oxide No More a Threat for Global Warming than Methane

Mainstream Media Jump on Extreme Weather Caused by Climate Change Bandwagon

The popular but mistaken belief that weather extremes are worsening be­cause of climate change has been bolstered in recent years by ever increasing hype in nearly all mainstream media coverage of extreme events, despite a lack of scientific evidence for the assertion. This month’s story by NPR (National Public Radio) in the U.S. is just the latest in a steady drumbeat of media misinformation.

Careful examination of the actual data reveals that if there is any trend in most weather extremes, it is downward rather than upward. In fact, a 2016 survey of extreme weather events since 1900 found strong evidence that the first half of the 20th century saw more weather extremes than the second half, when global warming was more prominent. More information can be found in my recent reports on weather extremes (here, here and here).

To be fair, the NPR story merely parrots the conclusions of an ostensibly scientific report from the AMS (American Meteorological Society), Explaining Extreme Events in 2021 and 2022 from a Climate Perspective. Both the AMS and NPR claim to show how the most extreme weather events of the previous two years were driven by climate change.

Nevertheless, all the purported connections rely on the dubious field of extreme-event attribution science, which uses statistics and climate models to supposedly detect the impact of global warming on weather disasters. The shortcomings of this approach are twofold. First, the models have a dismal track record in predicting the future (or indeed of hindcasting the past); and second, attri­bution studies that assign specific extremes to either natural variability or human causes are based on highly questionable statistical meth­odology (see here and here).  

So the NPR claim that “scientists are increasingly able to pinpoint exactly how the weather is changing as the earth heats up” and “how climate change drove unprecedented heat waves, floods and droughts in recent years” is utter nonsense. These weather extremes have occurred from time im­memorial, long before modern global warming began.

Yet the AMS and NPR insist that extreme drought in California and Nevada in 2021 was “six times more likely because of climate change.” This is completely at odds with a 2007 U.S. study which reconstructed the drought pattern in North America over the last 1200 years, using tree rings as a proxy.

The reconstruction is illustrated in the figure below, showing the drought area in western North America from 800 to 2003, as a percentage of the total land area. The thick black line is a 60-year mean, while the blue and red horizon­tal lines represent the average drought area during the periods 1900–2003 and 900–1300, respectively. Clearly, several unprecedently long and severe megadroughts have occurred in this region since the year 800; 2021 (not shown in the graph) was unexceptional.

The same is true for floods. A 2017 study of global flood risk concluded there is very little evidence that flooding is becoming more prevalent worldwide, despite average rainfall getting heavier as the planet warms. And, although the AMS report cites an extremely wet May of 2021 in the UK as likely to have resulted from climate change, “rescued” Victorian rainfall data reveals that the UK was just as wet in Victorian times as today.

The illusion that major floods are becoming more frequent is due in part to the world’s growing population and the appeal, in the more developed countries at least, of living near water. This has led to more people building their dream homes in vulner­able locations, on river or coastal floodplains, as shown in the next figure.

Depicted is what has been termed the “Expanding Bull’s-Eye Effect” for a hypothetical river flood impacting a growing city. It can be seen that the same flood will cause much more destruction in 2040 than in 1950. A larger and wealthier population exposes more individuals and property to the devastation wrought by intermittent flooding from rainfall-swollen rivers or storm surges. Population expansion beyond urban areas, not climate change, has also worsened the death toll and property damage from hurricanes and tornadoes.

In a warming world, it is hardly surprising that heat waves are becoming more common. However, the claim by the AMS and NPR that heat waves are now “more extreme than ever” can be questioned, either because heat wave data prior to 1950 is completely ignored in many compilations, or because the data before 1950 is sparse. No recent heat waves come close to matching the frequency and duration of those experienced worldwide in the 1930s.

The media are misleading and stoking fear in the public about perfectly normal extreme weather, although there are some notable exceptions such as The Australian. The alarmist stories of the others are largely responsible for the current near-epidemic of “climate anxiety” in children, the most vulnerable members of our society.

Next: New Observations Upend Notion That Global Warming Diminishes Cloud Cover

Are Ocean Surface Temperatures, Not CO2, the Climate Control Knob?

According to the climate change narrative, modern global warming is largely the result of human emissions of CO₂ into the atmosphere. But a recent lecture questioned that assertion with an important observation suggesting that ocean surface temperatures, not CO₂, are the planet’s climate control knob.

The lecture was delivered by Norwegian Ole Humlum, who was formerly a full professor in physical geography at both the University Centre in Svalbard, Norway and the University of Oslo, in addition to holding visiting positions in Scotland and the Faroe Islands. He currently publishes regular updates on the state of the global climate.

In his lecture, Humlum dwelt on temperature measurements of the world’s oceans. Since 2004, ocean temperatures have been studied in detail at depths of up to 2 km (1.2 miles), by means of a global array of almost 3,900 Argo profiling floats. These free-drifting robotic floats patrol the oceans, taking a deep dive every 10 days to probe the temperature and salinity of the watery depths, and transmitting the data to a satellite within hours of reaching the surface again. A 2018 map of the Argo array is shown below.

The next figure illustrates how the oceans have warmed during the period that the floats have been in operation, up to August 2020. The vertical scale is the global ocean temperature change in degrees Celsius averaged from 65^oS to 65^oN (excluding the polar regions), while the horizontal scale gives the depth up to 1,900 meters (6,200 feet).

You can see that warming has been most prominent at the surface, where the average sea surface temperature has gone up since 2004 by about 0.27 degrees Celsius (0.49 degrees Fahrenheit). The temperature increase deep down is an order of magnitude smaller. Most of the temperature rise at shallow depths comes from the tropics (30^oS to 30^oN) and the Antarctic (65^oS to 55^oS), although the Arctic (55^oN to 65^oN) measurements reveal considerable cooling down to about 1,400 meters (4,600 feet) in that region.

But Humlum’s most profound observation is of the timeline for Argo temperature measurements as a function of depth. These are depicted in the following figure showing global depth profiles for the tropical oceans in degrees Celsius, from 2004 to 2014. The tropics cover almost 40% of the earth’s surface; the oceans in total cover 71%.

The fluctuations in each Argo depth profile arise from seasonal variations in temperature from summer to winter, which are more pronounced at the surface than at greater depths. If you focus your attention on any yearly summer peak at zero depth, you will notice that it moves to the right – that is, to later times – as the depth increases. In other words, there is a time delay of any temperature change with depth.

From a correlation analysis of the Argo data, Humlum finds that the time delay at a depth of 200 meters (650 feet) is a substantial 20 months, so that it takes 20 months for a temperature increase or decrease at the tropical surface to propagate down to that depth. A similar, though smaller, delay exists between any change in sea surface temperature (SST) and corresponding temperature changes in the atmosphere and on land, as shown in the figure below.

At an altitude of 200 meters (650 feet) in the atmosphere, changes in the SST show up slightly less than half a month later. But in the lower troposphere, where satellite temperature measurements are made, the delay is 2 months, as it is also for land surface temperatures. Humlum’s crucial argument is that sea surface temperatures lead all other global temperature observations – that is, the global temperature signal originates at the ocean surface.

However, according to the CO₂ global warming hypothesis, the CO₂ signal originates at an altitude of about 9 km (5.6 miles) in the upper troposphere and is seen at the sea surface some time later. So the CO₂ hypothesis predicts that the sea surface is a lagging, not a leading indicator – exactly the opposite of what actual observations are telling us.

Humlum concludes that CO₂ cannot be the earth’s climate control knob and that our global climate is apparently controlled by the SST. The climate control knob must instead be whatever natural system controls sea surface temperatures. Potential candidates, he says, include the sun, cloud cover, sediments and organic life in the oceans, and the action of winds. Further research is needed to identify which of these possibilities truly powers the global climate.

Next: Mainstream Media Jumps on Extreme Weather Caused by Climate Change Bandwagon

New Research Finds Climate Models Unable to Reproduce Ocean Surface Temperatures

An earlier post of mine described how a group of prestigious U.S. climate scientists recently admitted that some climate models run too hot, greatly exaggerating future global warming. Now another group has published a research paper revealing that a whole ensemble of models is unable to reproduce observed sea surface temperature trends in the Pacific and Southern Oceans since 1979.

The observed trends include enhanced warming in the Indo-Pacific Warm Pool – a large body of water near Indonesia where sea surface temperatures exceed 28 degrees Celsius (82 degrees Fahrenheit) year-round – as well as slight cooling in the eastern equatorial Pacific, and cooling in the Southern Ocean.

Climate models predict exactly opposite effects in all three regions, as illustrated in the following figure. The top panel depicts the global trend in measured sea surface temperatures (SSTs) from 1979 to 2020, while the middle panel depicts the multimodel mean of hindcasted temperatures over the same period from a large 598-member ensemble, based on 16 different models and various possible CO₂ emissions scenarios ranging from low (SSP2-4.5) to high (RCP8.5) emissions. The bottom panel shows the difference.

You can see that the difference between observed and modeled temperatures is indeed marked. Considerable warming in the Indo-Pacific Warm Pool and the western Pacific, together with cooling in the eastern Pacific and Southern Ocean, are absent from the model simulations. The researchers found that sea-level pressure trends showed the same difference. The differences are especially pronounced for the Indo-Pacific Warm Pool.

The contributions of the individual model ensemble members to several key climate indices is illustrated in the figure below, where the letters A to P denote the 16 model types and the horizontal lines show the range of actual observed trends.

The top panel shows the so-called Pacific SST gradient, or difference between western and eastern Pacific; the center panel shows the ratio of Indo-Pacific Warm Pool warming to tropical mean warming; and the bottom panel portrays the Southern Ocean SST. All indices are calculated as a relative rate of warming per degree Celsius of tropical mean SST change. It is clear that the researchers’ findings hold across all members of the ensemble.

The results suggest that computer climate models have systematic biases in the transient response of ocean temperature patterns to any anthropogenic forcing, say the research authors. That’s because the contribution of natural variability to multidecadal trends is thought to be small in the Indo-Pacific region.

To determine whether the difference between observations and models comes from internal climate variability or from climate forcing not captured by the models, the researchers conducted a signal-to-noise maximizing pattern analysis. This entails maximizing the signal-to-noise ratio in global temperature patterns, where the signal is defined as the difference between observations and the multimodel mean on 5-year and longer timescales, and the noise consists of inter-model differences, inter-ensemble-member differences, and less-than-5-year variability. The chosen ensemble had 160 members.

As seen in the next figure, the leading pattern from this analysis (Difference Pattern 1) shows significant discrepancies between observations and models, similar to the difference panel designated “e” in the first figure above. Lack of any difference would appear as a colorless pattern. Only one of the 598 ensemble members came anywhere close to matching the observed trend in this pattern, indicating that the models are the problem, not a misunderstanding of natural variability.

The second pattern (Difference Pattern 2), which focuses on the Northern Pacific and Atlantic Oceans, also shows an appreciable difference between models and observations. The research team found that only a handful of ensemble members could reproduce this pattern. They noted that the model that most closely matched the trend in Pattern 1 was furthest from reproducing the Pattern 2 trend.

Previously proposed explanations for the differences seen between observed and modeled trends in sea surface temperatures include systematic biases in the transient response to climate forcing, and model biases in the representation of multidecadal natural variability.

However, the paper’s authors conclude it is extremely unlikely that the trend discrepancies result entirely from internal variability, such as the anomalous return to warming during the recent cool phase of the PDO (Pacific Decadal Oscillation) as proposed by other researchers. The authors say that the large difference in the Warm Pool warming rate between models and observations (“b” in the second figure above) is particularly hard to explain by natural variability.

They suggest that multidecadal variability of both tropical and subtropical sea surface temperatures is much too weak in climate models. The authors suggest that damping feedbacks in response to Warm Pool warming may be too strong in the models, which would reduce both the modeled warming rate and the modeled amplitude of multidecadal variability.

Next: Are Ocean Surface Temperatures, Not CO2, the Climate Control Knob?

Climate Heresy: To Avoid Extinction We Need More, Not Less CO2

A recent preprint advances the heretical idea that all life on Earth will perish in as little as 42,000 years unless we take action to boost – not lower – the CO₂ level in the atmosphere. The preprint’s author claims that is when the level could fall to a critical 150 ppm (parts per million), below which plants die due to CO₂ starvation.

Some of the arguments of author Brendan Godwin, a former Australian meteorologist, are sound. But Godwin seriously underestimates the time frame for possible extinction. It can easily be shown that the interval is in fact millions of years.

Plants are essential for life because they are the source, either directly or indirectly, of all the food that living creatures eat. Both CO₂ and water, as well as sunlight, are necessary for the photosynthesis process by which plants grow. In the carbon cycle, the ultimate repository for CO₂ pulled out of both the air and the oceans is limestone or calcium carbonate (CaCO₃), of which there are two types: chemical and biological.

Chemical limestone is formed from the weathering over time of silicate rocks, which make up about 90% of the earth’s crust, and to a lesser extent, of carbonate rocks. Silicate weathering draws CO₂ out of the atmosphere when the CO₂ combines with rainwater to form carbonic acid (H₂CO₃) that dissolves silicates. A representative chemical reaction for calcium silicate (CaSiO₃) is

CaSiO₃ + 2CO₂ + H₂O → Ca²⁺ + 2HCO₃^- + SiO₂.

The resulting calcium (Ca²⁺) and bicarbonate (HCO₃^-) ions, together with dissolved silica (SiO₂), are then carried away mostly by rivers to the oceans. There, calcium carbonate (CaCO₃) precipitates when marine organisms utilize the Ca²⁺ and HCO₃^- ions to build their skeletons and shells:

Ca²⁺ + 2HCO₃^- → CaCO₃ + CO₂ + H₂O.

Once the organisms die, the CaCO₃ skeletons and shells sink to the ocean floor and are deposited as chemical limestone in deep-sea sediment.

Biological limestone, on the other hand, comes from fossilized coral reefs and is approximately twice as abundant as chemical limestone. Just like the marine organisms or plankton that ultimately form chemical limestone, the polyps that constitute a coral build the chambers in which they live out of CaCO₃. Biological limestone from accumulated coralline debris accumulates mainly in shallow ocean waters, and is transformed over time by plate tectonic processes into major outcrops on land and in the highest mountains – even the top of Mount Everest.

Godwin’s estimate of only 42,000 years before life is extinct stems from a misunderstanding about the carbon cycle, which is illustrated in the figure below depicting the global carbon budget in gigatonnes of carbon. Carbon stocks are shown in blue, with annual flows between carbon reservoirs shown in red.

The carbon sequestered as chemical limestone in deep-sea sediment, and as biological limestone, is represented by the 100 million gigatonnes stored in the earth’s crust. As you can see, today’s atmosphere contains approximately 850 gigatonnes of carbon (as CO₂) and the oceans another 38,000 gigatonnes, most of which was originally dissolved as atmospheric CO₂.

The erroneous estimate of Godwin simply divides the 38,000 gigatonnes of carbon in the oceans by 0.9 gigatonnes per year, which is the known rate of carbon sequestration into chemical and biological limestone combined; chemical weathering of silicate rocks contributes 0.3 gigatonnes per year, while fossilized coral contributes 0.6 gigatonnes per year.

This calculation is wrong because Godwin fails to understand that the carbon cycle is dynamic, with carbon constantly being exchanged between land, atmospheric and ocean reservoirs. The carbon sequestered into chemical and biological limestone is included in the flow from rivers to ocean and in ocean uptake in the figure above. But there are many flows in the opposite direction that replenish carbon in the atmosphere, even when fossil fuel burning is ignored. Simply depleting the ocean reservoir will not lead to extinction.

A realistic estimate can be made by assuming that atmospheric carbon will continue to decline at the same rate as it has over the past 540 million years. As shown in the next figure, the concentration of CO₂ in the atmosphere over that period has dropped from a high of about 7,000 ppm at the beginning of the so-called Cambrian Explosion, to today’s 417 ppm.

Using a conversion factor of 2.13 gigatonnes of carbon per ppm of atmospheric CO₂, the drop corresponds to an average decline of approximately 26 kilotonnes of carbon per year. At that rate, the 150 ppm (320 gigatonnes) level at which life on earth would begin to die will not be reached until 22 million years from now.

Given that the present CO₂ level is rising due to fossil fuel emissions, the 22 million years is likely to be an underestimate. However, ecologist Patrick Moore points out that a future cessation of fossil fuel burning could make the next ice age – which may be only thousands of years away – devastating for humanity, as temperatures and CO₂ levels could fall to unprecedentedly low levels, drastically reducing plant growth and creating widespread famine.

Next: New Research Finds Climate Models Unable to Reproduce Ocean Surface Temperatures

Recent Marine Heat Waves Caused by Undersea Volcanic Eruptions, Not Human CO2

In a previous post, I showed how submarine volcanic eruptions don’t contribute to global warming, despite the release of enormous amounts of explosive energy. But they do contribute to regional climate change in the oceans, such as marine heat waves and shrinkage of polar sea ice, explained a retired geologist in a recent lecture.

Wyss Yim, who holds positions at several universities in Hong Kong, says that undersea volcanic eruptions – rather than CO₂ – are an important driver of regional climate variability. The release of geothermal heat from these eruptions can explain oceanic heat waves, polar sea-ice changes and stronger-than-normal cycles of ENSO (the El Niño – Southern Oscillation), which causes temperature fluctuations and other climatic effects in the Pacific.

Submarine eruptions can eject basaltic lava at temperatures as high as 1,200 degrees Celsius (2,200 degrees Fahrenheit), often from multiple vents over a large area. Even though the hot lava is quickly quenched by the surrounding seawater, the heat absorbed by the ocean can have local, regional impacts that last for years.

The Pacific Ocean in particular is a major source of active terrestrial and submarine volcanoes, especially around the Ring of Fire bounding the Pacific tectonic plate, as illustrated in the figure below. Yim has identified eight underwater eruptions in the Pacific from 2011 to 2022 that had long-lasting effects on the climate, six of which emanated from the Ring of Fire.

One of these eruptions was from the Nishino-shima volcano south of Tokyo, which underwent a massive blow-out, initially undersea, that persisted from March 2013 to August 2015. Yim says the event was the principal cause of the so-called North Pacific Blob, a massive pool of warm seawater that formed in the northeast Pacific from 2013 to 2015, extending all the way from Alaska to the Baja Peninsula in Mexico and up to 400 meters (1,300 feet) deep. Climate scientists at the time, however, attributed the Blob to global warming.

The Nishino-shima eruption, together with other submarine eruptions in the Pacific during 2014 and 2015, was a major factor in prolonging and strengthening the massive 2014-2017 El Niño. A map depicting sea surface temperatures in January 2014, at the onset of El Niño and almost a year after the emergence of the Blob, is shown in the next figure. At that time, surface temperatures across the Blob were about 2.5 degrees Celsius (4.5 degrees Fahrenheit) above normal.

By mid-2014, the Blob covered an area approximately 1,600 km (1,000 miles) square. Its vast extent, states Yim, contributed to the gradual decline of Arctic sea ice between 2014 and 2016, especially in the vicinity of the Bering Strait. The Blob also led to two successive years without winter along the northeast Pacific coast.

Biodiversity in the region suffered too, with sustained toxic algal blooms. Yet none of this was caused by climate change.

The 2014-2017 El Niño was further exacerbated by the eruption from May to June 2015 of the Wolf volcano on the Galapagos Islands in the eastern Pacific. Although the Wolf volcano is on land, its lava flows entered the ocean. The figure below shows the location of the Wolf eruption, along with submarine eruptions of both the Axial Seamount close to the Blob and the Hunga volcano in Tonga in the South Pacific.

According to Yim, the most significant drivers of the global climate are changes in the earth’s orbit and the sun, followed by geothermal heat, and – only in third place – human-induced changes such as increased greenhouse gases. Geothermal heat from submarine volcanic eruptions causes not only marine heat waves and contraction of polar sea ice, but also local changes in ocean currents, sea levels and surface winds.

Detailed measurements of oceanic variables such as temperature, pressure, salinity and chemistry are made today by the worldwide network of 3,900 Argo profiling floats. The floats are battery-powered robotic buoys that patrol the oceans, sinking 1-2 km (0.6-1.2 miles) deep once every 10 days and then bobbing up to the surface, recording the properties of the water as they ascend. When the floats eventually reach the surface, the data is transmitted to a satellite.

Yim says his studies show that the role played by submarine volcanoes in governing the planet’s climate has been underrated. Eruptions of any of the several thousand active underwater volcanoes can have substantial regional effects on climate, as just discussed.

He suggests that the influence of volcanic eruptions on atmospheric and oceanic circulation should be included in climate models. The only volcanic effect in current models is the atmospheric cooling produced by eruption plumes.

Next: Climate Heresy: To Avoid Extinction We Need More, Not Less CO2

Ample Evidence Debunks Gloomy Prognosis for World’s Coral Reefs

According to a just-published research paper, dangers to the world’s coral reefs due to climate change and other stressors have been underestimated and by 2035, the average reef will face environmental conditions unsuitable for survival. This is scientific nonsense, however, as there is an abundance of recent evidence that corals are much more resilient than previously thought and recover quickly from stressful events.

The paper, by a trio of environmental scientists at the University of Hawai‘i, attempts to estimate the year after which various anthropogenic (human-caused) disturbances acting simultaneously will make it impossible for coral reefs to adapt and survive. The disturbances examined are marine heat waves, ocean acidification, storms, land use changes, and pressures from population density such as overfishing, farming runoff and coastal development.

Of these disturbances, the two expected to have the greatest future effect on coral reefs are marine heat waves and ocean acidification, supposedly exacerbated by rising greenhouse gas emissions. The figure to the left shows the scientists’ projected dates of environmental unsuitability for continued existence of the world’s coral reefs, assuming an intermediate CO2 emissions scenario (SSP2). The yellow curve is for marine heat waves, the green curve for ocean acidification.

You can see that the projected unsuitability rises to an incredible 75% by the end of the century for both perturbations, and even surpasses 50% for marine heat waves by 2050. The red arrow indicates the time difference at 75% unsuitability between heat waves considered alone and all disturbances combined (solid black curve).

But these gloomy prognostications are refuted by several recent field studies, two of which I discussed in an earlier blog post. The latest paper, published in May this year, reports on a 10-year study of coral-reef stability on Palmyra Atoll in the remote central Pacific Ocean. The scuba-diving researchers, from California’s Scripps Institution of Oceanography and Saudi Arabia’s King Abdullah University, discovered – by analyzing more than 1,500 digital images – that Palmyra reefs made a remarkable recovery from two major bleaching events in 2009 and 2015.

Bleaching occurs when the multitude of polyps that constitute a coral eject the microscopic algae that normally live inside the polyps and give coral its striking colors. Hotter than normal seawater causes the algae to poison the coral that then expels them, turning the polyps white. The bleaching events studied by the Palmyra researchers were a result of prolonged El Niños in the Pacific.

However, the researchers found that, at all eight Palmyra sites investigated, the corals returned to pre-bleaching levels within two years. This was true for corals on both a wave-exposed fore reef and a sheltered reef terrace. Stated Jennifer Smith, one of the paper’s coauthors,  “During the warming event of 2015, we saw that up to 90% of the corals on Palmyra bleached but in the year following we saw less than 10% mortality.”

The rapid coral recovery can be seen in the figure on the left below, showing the percentage of coral cover from 2009 to 2019 at all sites combined; FR denotes fore reef, RT reef terrace, and the dashed vertical lines indicate the 2009 and 2015 bleaching events. It’s clear there was only a small change in the reef’s coral and algae populations after a decade, despite the violent disruption of two bleaching episodes. A typical healthy reefscape is shown on the right.

Another 2022 study, discussed in my earlier post, came to much the same conclusions for a massive reef of giant rose-shaped corals hidden off the coast of Tahiti, the largest island in French Polynesia in the South Pacific. The giant corals measure more than 2 meters (6.5 feet) in diameter. Again, the reef survived a mass 2019 bleaching event almost unscathed.

Both these studies were conducted on relatively pristine coral reefs, free from local human stressors such as fishing, pollution, coastal development and tourism. But the same ability of corals to recover from bleaching events has been demonstrated in research on Australia’s famed Great Barrier Reef, many parts of which are subject to such stressors.

Studies in 2021 and 2020 (see here and here) found that both the Great Barrier Reef and coral colonies on reefs around Christmas Island in the Pacific were able to recover quickly from bleaching caused by the 2015-17 El Niño, even while seawater temperatures were still higher than normal. Recovery of the Great Barrier Reef is illustrated in the figure below, showing that the amount of coral on the reef in 2021 and 2022 was at record high levels, in spite of extensive bleaching a few years before.

Apart from making a number of arbitrary and questionable assumptions, the new University of Hawai‘i research is fundamentally flawed because it fails to take into account the ability of corals to rebound from potentially devastating events.

Next: Recent Marine Heat Waves Caused by Undersea Volcanic Eruptions, Not Human CO2

Challenges to the CO2 Global Warming Hypothesis: (7) Ocean Currents More Important than the Greenhouse Effect

A rather different challenge to the CO₂ global warming hypothesis from the challenges discussed in my previous posts postulates that human emissions of CO₂ into the atmosphere have only a minimal impact on the earth’s temperature. Instead, it is proposed that current global warming comes from a slowdown in ocean currents.

The daring challenge has been made in a recent paper by retired Australian meteorologist William Kininmonth, who was head of his country’s National Climate Centre from 1986 to 1998. Kininmonth rejects the claim of the IPCC (Intergovernmental Panel on Climate Change) that greenhouse gases have caused the bulk of modern global warming. The IPCC's claim is based on the hypothesis that the intensity of cooling longwave radiation to space has been considerably reduced by the increased atmospheric concentration of gases such as CO₂.

But, he says, the IPCC glosses over the fact that the earth is spherical, so what happens near the equator is very different from what happens at the poles. Most absorption of incoming shortwave solar radiation occurs over the tropics, where the incident radiation is nearly perpendicular to the surface. Yet the emission of outgoing longwave radiation takes place mostly at higher latitudes. Nowhere is there local radiation balance.

In an effort by the climate system to achieve balance, atmospheric winds and ocean currents constantly transport heat from the tropics toward the poles. Kininmonth argues, however, that radiation balance can’t exist globally, simply because the earth’s average surface temperature is not constant, with an annual range exceeding 2.5 degrees Celsius (4.5 degrees Fahrenheit). This shows that the global emission of longwave radiation to space varies seasonally, so radiation to space can’t define Earth’s temperature, either locally or globally.

In warm tropical oceans, the temperature is governed by absorption of solar shortwave radiation, together with absorption of longwave radiation radiated downward by greenhouse gases; heat carried away by ocean currents; and heat (including latent heat) lost to the atmosphere. Over the last 40 years, the tropical ocean surface has warmed by about 0.4 degrees Celsius (0.7 degrees Fahrenheit).

But the warming can’t be explained by rising CO₂ that went up from 341 ppm in 1982 to 417 ppm in 2022. This rise boosts the absorption of longwave radiation at the tropical surface by only 0.3 watts per square meter, according to the University of Chicago’s MODTRAN model, which simulates the emission and absorption of infrared radiation in the atmosphere. The calculation assumes clear sky conditions and tropical atmosphere profiles of temperature and relative humidity.

The 0.3 watts per square meter is too little to account for the increase in ocean surface temperature of 0.4 degrees Celsius (0.7 degrees Fahrenheit), which in turn increases the loss of latent and “sensible” (conductive) heat from the surface by about 3.5 watts per square meter, as estimated by Kininmonth.

So twelve times as much heat escapes from the tropical ocean to the atmosphere as the amount of heat entering the ocean due to the increase in CO₂ level. The absorption of additional radiation energy due to extra CO₂ is not enough to compensate for the loss of latent and sensible heat from the increase in ocean temperature.

The minimal contribution of CO₂ is evident from the following table, which shows how the amount of longwave radiation from greenhouse gases absorbed at the tropical surface goes up only marginally as the CO₂ concentration increases. The dominant greenhouse gas is water vapor, which produces 361.4 watts per square meter of radiation at the surface in the absence of CO₂; its value in the table (surface radiation) is the average global tropical value.

You can see that the increase in greenhouse gas absorption from preindustrial times to the present, corresponding roughly to the CO₂ increase from 300 ppm to 400 ppm, is 0.62 watts per square meter. According to the MODTRAN model, this is almost the same as the increase of 0.63 watts per square meter that occurred as the CO₂ level rose from 200 ppm to 280 ppm at the end of the last ice age – but which resulted in tropical warming of about 6 degrees Celsius (11 degrees Fahrenheit), compared with warming of only 0.4 degrees Celsius (0.7 degrees Fahrenheit) during the past 40 years.

Therefore, says Kininmonth, the only plausible explanation left for warming of the tropical ocean is a slowdown in ocean currents, those unseen arteries carrying the earth’s lifeblood of warmth away from the tropics. His suggested slowing mechanism is natural oscillations of the oceans, which he describes as the inertial and thermal flywheels of the climate system.

Kininmonth observes that the overturning time of the deep-ocean thermohaline circulation is about 1,000 years. Oscillations of the thermohaline circulation would cause a periodic variation in the upwelling of cold seawater to the tropical surface layer warmed by solar absorption; reduced upwelling would lead to further heating of the tropical ocean, while enhanced upwelling would result in cooling.

Such a pattern is consistent with the approximately 1,000-year interval between the Roman and Medieval Warm Periods, and again to current global warming.

Next: Ample Evidence Debunks Gloomy Prognosis for World’s Coral Reefs

The Scientific Method at Work: The Carbon Cycle Revisited, Again

In a previous post, I demonstrated how a new model of the carbon cycle, described in a 2020 preprint, is falsified by empirical observations that fail to confirm a prediction of the model. The crucial test of any scientific hypothesis is whether its predictions match real-world observations. But a newly publicized discussion now questions the foundations of the model itself.

The model in question, developed by U.S. physicist Ed Berry, describes quantitatively the exchange of carbon between the earth’s land masses, atmosphere and oceans. Berry argues that natural emissions of CO₂ into the atmosphere since 1750 have increased as the world has warmed, and that only 25% of the increase in atmospheric CO₂ after 1750 is from humans.

This is contrary to the CO₂ global warming hypothesis that human emissions have caused all of the CO₂ increase above its preindustrial level in 1750 of 280 ppm (parts per million). The CO₂ hypothesis is based on the apparent correlation between rising worldwide temperatures and the CO₂ level in the lower atmosphere, which has gone up by 49% over the same period.

Natural CO₂ emissions are part of the carbon cycle that includes fauna and flora, as well as soil and sedimentary rocks. Human CO₂ from burning fossil fuels constitutes less than 5% of total CO₂ emissions into the atmosphere, the remaining emissions being natural. Atmospheric CO₂ is absorbed by vegetation during photosynthesis, and by the oceans through precipitation. The oceans also release CO₂ as the temperature climbs.

In a recent discussion between Ed Berry and the CO₂ Coalition, the Coalition says that Berry confuses the 5% of CO₂ emissions originating from fossil fuels with the percentage of atmospheric CO₂ molecules that actually come from fossil fuel burning. This percentage is very small, because the molecules are continually recycled and thus “diluted” with the much larger quantity of CO₂ molecules from natural emissions.

Physicist David Andrews amplifies this comment of the CO₂ Coalition in a 2022 preprint, by pointing out that total CO₂ emissions into the atmosphere from human activity over time exceed the rise in atmospheric CO₂ over the same interval. So all the modern CO₂ increase (from 280 to 416 ppm) must come from human emissions. Adds Andrews:

… we know immediately that land and sea reservoirs together have been net sinks, not sources, of carbon during this period. We can be sure of this without knowledge of the detailed inventory changes of individual non-atmospheric reservoirs. … Global uptake is simply what is left over after atmospheric accumulation has been subtracted from total emissions. If more carbon was injected into the atmosphere by fossil fuel burning than stayed there, it had to have gone somewhere else.

The arguments of both Andrews and the CO₂ Coalition are at odds with Berry’s calculations, depicted in the figure below; H denotes human and N natural CO₂.

This figure shows that the sum total of human CO₂ emissions (blue dots) exceeds the rise in atmospheric CO₂ (black dots), at least since 1960, in agreement with Andrews’ comment. Where Berry goes astray is by claiming that natural emissions, represented by the area between the blue and red solid lines, have not stayed at the same 280 ppm level over time, but have gone up as global temperatures have increased.

Such a claim is extremely puzzling, as the model requires the addition to the atmosphere of approximately 100 ppm of CO₂ from natural sources since 1840 – an amount far in excess of the roughly 10 ppm of CO₂ outgassed from the oceans as ocean temperatures rose about 1 degree Celsius (1.8 degrees Fahrenheit) over that time. Berry acknowledges the problem, but only proposes unphysical explanations, such as mysteriously adding new carbon to the carbon cycle.

The falsified prediction of his model, on the other hand, involves the atmospheric concentration of the radioactive carbon isotope ¹⁴C, produced by cosmic rays interacting with nitrogen in the upper atmosphere. The concentration of ¹⁴C almost doubled following above-ground nuclear bomb tests in the 1950s and 1960s, and has since been slowly dropping. At the same time, concentrations of the stable carbon isotopes ¹²C and ¹³C, generated by fossil-fuel burning, have been steadily rising. Because the carbon in fossil fuels is millions of years old, all the ¹⁴C in fossil-fuel CO₂ has decayed away.

Although Berry claims that his model’s prediction of the recovery in ¹⁴C concentration since 1970 matches experimental observations, Andrews found that Berry had confused the concentration of ¹⁴C with its isotopic or abundance ratio relative to ¹²C, as I described in my earlier post.

As a result, Berry’s carbon cycle model does not replicate the actual measurements of ¹⁴C concentration in the atmosphere since 1970, as he insists it does. Needless to say, he also disputes the arguments of Andrews and the CO₂ Coalition about the very basis of his model.

Next: Challenges to the CO2 Global Warming Hypothesis: (7) Ocean Currents More Important than the Greenhouse Effect

Climate-Related Disasters Wrongly Linked to Global Warming by Two International Agencies

Two 2022 reports by highly acclaimed international agencies – CRED (Centre for Research on the Epidemiology of Disasters), a Belgian non-profit, and the WMO (World Meteorological Organi­zation), a UN agency – insist that climate-related disasters are escalating as the world warms. But the evidence shows that such a claim is indisputably wrong.

The 2022 CRED report, which covers events in 2021, draws a strong link between global warming and climate disasters, the majority of which are floods and storms. The report pointedly comments that “… 2021 was marked by an increase in the number of disaster events,” and that the total of 432 catastrophic events was “considerably higher” than the annual average of 347 catastrophic events for 2001-2020. A breakdown of these numbers by disaster category is presented in the figure below from the report.

Both CRED statements, while literally true, are dishonest as they completely ignore statistics. Although the total of 432 events for 2021 was indeed higher than the 20-year average from 2001 to 2020, the total for, say, 2018 of 289 events was lower than the 19-year annual average from 2001 to 2018 of 333 events. The individual yearly totals are unrelated – independent events in the language of statistics – and any comparison of them to a long-term average is meaningless.

The statistical inadequacy of such a comparison is also made clear by examining the long-term trend in CRED’s data. The next figure shows the yearly number of climate-related disasters globally from 2000 through 2020 by major category. The disasters are those in the yellow climatological (droughts, glacial lake outbursts and wildfires), green meteorological (storms, extreme temperatures and fog), and blue hydrological (floods, landslides and wave action) categories.

The disaster data comes from CRED’s EM-DAT (Emergency Events Database). To be recorded as a disaster, an event must meet at least one of the following criteria: 10 or more people reported killed; 100 or more people reported affected; a state of emergency declared; or a call put out for international assis­tance.

What the figure shows is that the total number of climate-related disasters exhibits a distinctly declining trend from 2000 to 2020, falling by 11% over 21 years. Yet the same graph for the period one year later, from 2001 to 2021, shows a decline of only 1% over that 21-year interval. As any statistician knows, both the trend and the average value of a time series are highly sensitive to the endpoints chosen. Nevertheless, the disaster trend is clearly downward.

The 2022 WMO report makes the same error as an earlier CRED report and a previous WMO report in claiming that climate-related disasters have increased significantly since 1970. A key message of the 2022 report is that “weather-related disasters have increased fivefold over the last 50 years,” as purportedly shown by the WMO figure below. The WMO data is derived from the same EM-DAT database as the CRED data.

However, the WMO claim is nonsense and the figure is highly misleading. This is because, just like similar data in the earlier CRED report, the claim fails to take into account a major increase in disaster reporting since 1998 due to the arrival of the Internet. Climate writers Paul Homewood and Roger Pielke Jr. uncovered a sudden jump – a near doubling – in the annual number of disasters listed in EM-DAT in 1998 and the years thereafter. Surprisingly, CRED had acknowledged as much both in its 2004 disaster report:

Over the past 30 years, development in telecommunications, media and increased international cooperation has played a critical role in the number of disasters reported at an international level. In addition, increases in humanitarian funds have encouraged reporting of more disasters, especially smaller events that were previously managed locally.

and even more explicitly in its 2006 disaster report:

Two periods can be distinguished: 1987–1997, with the number of disasters varying generally between 200 and 250; and 2000–2006, with the number of disasters increasing by nearly a multiple factor of two. An increase of this magnitude can be partially explained by increased reporting of disasters, particularly by press organizations and specialized agencies.

That the impact of natural disasters is diminishing over time can be seen in data on the associated loss of life. The next figure illustrates the annual global number of deaths from natural disasters, including weather extremes, from 1900 to 2015, corrected for population increase over time and averaged by decade.

 Because the data is compiled from the same EM-DAT da­tabase, the annual number of deaths shows an uptick from the 1990s to the 2000s. It is clear though that disaster-related deaths from extreme weather have been falling since the 1920s and are now approaching zero. This is due as much to improved planning, more robust structures and early warning systems, as it is to diminishing numbers of natural disasters. And, as can be seen from the figure, it is earthquakes – entirely natural events – that have been the deadliest disasters over the last two decades.

Ignoring all the evidence, however, the press release accompanying the latest WMO report proclaims that “Climate science is clear: we are heading in the wrong direction,” the UN Secretary-General adding, with characteristic hype, that the report “shows climate impacts heading into uncharted territory of destruction.”

A more detailed discussion of the erroneous claims of both CRED and the WMO can be found in my two most recent reports on weather extremes (here and here).

Next: The Scientific Method at Work: The Carbon Cycle Revisited, Again

Arctic Sea Ice Refuses to Disappear, despite Ever Rising Arctic Temperatures

The loss of sea ice in the Arctic due to global warming has long been held up by the mainstream media and climate activists as cause for alarm. The ice would be completely gone in summer, they predicted, by 2013, then 2016, then 2030. But the evidence shows that Arctic ice is not cooperating, and in fact its summer extent in 2022 was the same as in 2008. And this stasis has occurred even as Arctic temperatures continue to soar.

The minimum summer Arctic ice extent this month was about 67% of its coverage in 1979, which is when satellite measurements of sea ice in the Arctic and Antarctic began. The figure to the left shows satellite-derived images of Arctic sea ice extent in the summer of 2022 (September 18) and the winter of 2021 (March 7) , which was similar to 2022. Sea ice shrinks during summer months and expands to its maximum extent during the winter.

Over the interval from 1979 to 2022, Arctic summer ice detached from the Russian coast, although it still encases northern Greenland as can be seen. The figure below compares the monthly variation of Arctic ice extent from its March maximum to the September minimum, for the years 2022 (blue curve) and 2008 (red curve). The 2022 summer minimum is seen to be almost identical to that in 2008, as was the 2021 minimum, with the black curve depicting the median extent over the period from 1981 to 2010.

The next figure illustrates the estimated Arctic ice thickness and volume at the 2022 minimum. The volume depends on both ice extent and thickness, which varies with location as well as season. Arctic ice thickness is notoriously difficult to measure, the best data coming from limited submarine observations.

The thickest, and oldest, winter ice currently lies along the northern coasts of the Canadian Arctic Archipelago and Greenland. According to a trio of Danish research institutions, just 20% of the Arctic ice pack today consists of thick ice more than one to two years old, compared to 40% in 1983. Thick, multi-year ice doesn’t melt away in the summer, but much of the ice cover currently formed during winter consists of thin, first-year ice. 

What is surprising, however, is that the lack of any further loss in summer ice extent since 2008 has been accompanied by a considerable increase in Arctic temperature. The left panel of the next figure, from a dataset compiled by the European Union’s Copernicus Climate Change Service, shows the mean surface temperature in the Arctic since 1979.

You can see that the Arctic has been warming steadily since at least 1979, when the first satellite measurements were made. As shown in the figure, the mean temperature there shot up by 3 degrees Celsius (5.4 degrees Fahrenheit), compared to global warming over the same interval of only 0.68 degrees Celsius (1.2 degrees Fahrenheit). That’s an Arctic warming rate 4 times faster than the globe as a whole. From 2008 to 2022, during which the summer ice extent remained unchanged on average, the Arctic nevertheless warmed by about 1.3 degrees Celsius (2.3 degrees Fahrenheit).

This phenomenon of excessive warming at the North Pole is known as Arctic amplification, depicted numerically in the right panel of the figure above. The effect shows strong regional variability, with some areas – such as the Taymyr Peninsula region in Siberia and the sea near Novaya Zemlya Island – warming by as much as seven times the global average. The principal reason for the high amplification ratio in these areas is exceptionally low winter ice cover, which is most pronounced in the Barents Sea near Novaya Zemlya.

The amplification is a result of so-called albedo (reflectivity) feedback. Sea ice is covered by a layer of white snow that reflects around 85% of incoming sunlight back out to space. As the highly reflective ice melts from global warming, it exposes more of the darker seawater underneath. The less reflective seawater absorbs more incoming solar radiation than sea ice, pushing the temperature higher. This in turn melts more ice and exposes more seawater, amplifying the warming in a feedback loop.

Interestingly, computer climate models, most of which exaggerate the impact of global warming, underestimate Arctic warming. The models typically estimate an average Arctic amplification ratio of about 2.5, much lower than the average ratio of 4 deduced from actual observations. A recent research study attributes this difference to possible errors in the modeled sensitivity to greenhouse gas forcing, and in the distribution of heating from the forcing between the atmosphere, cryosphere and ocean.

They also suggest that climate models underestimate multi-decadal internal variability, especially of atmospheric circulation in mid-latitudes (30^o to 60^o from the equator), which influences temperature variability in the Arctic as well.

Next: Climate-Related Disasters Wrongly Linked to Global Warming by Two International Agencies