Greatly intensifying the attack on modern science is invocation of the precautionary principle – a concept developed by 20th-century environmental activists. Targeted at decision making when the available scientific evidence about a potential environmental or health threat is highly uncertain, the precautionary principle has been used to justify a number of environmental policies and laws around the globe. Unfortunately for science, the principle has also been used to support political action on alleged hazards, in cases where there’s little or no evidence for those hazards.

The origins of the precautionary principle can be traced to the application in the early 1970s of the German principle of “Vorsorge” or foresight, based on the belief that environmental damage can be avoided by careful forward planning. The “Vorsorgeprinzip” became the foundation for German environmental law and policies in areas such as acid rain, pollution and global warming. The principle reflects the old adage that “it’s better to be safe than sorry,” and can be regarded as a restatement of the ancient Hippocratic oath in medicine, “First, do no harm.”

Formally, the precautionary principle can be stated as:

When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.

But in spite of its noble intentions, the precautionary principle in practice is based far more on political considerations than on science. It’s the “not fully established scientifically” statement that both embraces the principle involved and, at the same time, leaves it open to manipulation and subversion of science.

A notable example of the intrusion of precautionary principle politics into science is the bans on GMO (genetically modified organism) crops by more than half the countries in the European Union. The bans stem from the widespread, fear-based belief that eating genetically altered foods is unsafe, despite the lack of any scientific evidence that GMOs have ever caused harm to a human.

In a 2016 study by the U.S. NAS (National Academy of Sciences, Engineering and Medicine), no substantial evidence was found that the risk to human health was any different for current GMO crops on the market than for their traditionally crossbred counterparts. This conclusion came from epidemiological studies conducted in the U.S. and Canada, where the population has consumed GMO foods since the late 1990s, and similar studies in the UK and Europe, where very few GMO foods are eaten.

One of the biggest issues with the precautionary principle is that it essentially advocates risk avoidance. But risk avoidance carries its own risks.

Dangers, great and small, are an accepted part of everyday life. We accept the risk, for example, of being killed or badly injured while traveling on the roads because the risk is outweighed by the convenience of getting to our destination quickly, or by our desire to have fresh food available at the supermarket. Applying the precautionary principle would mean, in addition to the safety measures already in place, reducing all speed limits to 10 mph or less – a clearly impractical solution that would take us back to horse-and-buggy days.  

Another, real-life example of an unintended consequence of the precautionary principle is what happened in Fukushima, Japan in the aftermath of the nuclear accident triggered by a massive earthquake and tsunami in 2011. As described by the authors of a recent discussion paper, Japan’s shutdown of nuclear power production as a safety measure and its replacement by fossil-fueled power raised electricity prices by as much as 38%, decreasing consumption of electricity, especially for heating during cold winters. This had a devastating effect: in the authors’ words,

“Our estimated increase in mortality from higher electricity prices significantly outweighs the mortality from the accident itself, suggesting the decision to cease nuclear production caused more harm than good.”

Adherence to the precautionary principle can also stifle innovation and act as a barrier to technological development. In the worst case, an advantageous technology can be banned because of its potentially negative impact, leaving its positive benefits unrealized. This could well be the case for GMOs. The more than 30 nations that have banned the growing of genetically engineered crops may be shutting themselves off from the promise of producing cheaper and more nutritious food.

The precautionary principle pits science against politics. In an ideal world, the conflict between the two would be resolved wisely. As things are, however, science is often subjugated to the needs and whims of policy makers.