Today Nieuwsuur published a number of facts about the climate debate. It refers, among other things, to research showing that 97% of scientists agree that climate change is caused by humans.
According to some critics, this figure is incorrect. That is how Thierry Baudet refers in one Tweet to an article that was previously published on Forbes in which a study of the consensus among scientists is disputed.
How does this work exactly?
The article Baudet refers to criticizes an investigation by Australian researcher John Cook. Cook researched the theme with eight other colleagues in 2013 by viewing 11,944 articles in peer-reviewed journals (ie with a quality test by fellow scientists) in which the terms 'climate change' or 'global warming' were summarized in the summary. (global climate change or global warming). He wanted to see if you could take a position on it about the human influence on the climate.
Cook and his colleagues found that about 8,000 of the aforementioned studies did not take an explicit position on whether climate warming is caused by humans; Of the remaining 4,000 studies, 97% say that climate warming comes from humans.
According to climate scientist Bart Verheggen, who did research on this theme in the Netherlands, it is not surprising that many articles do not take an explicit position on the influence of humans on climate. According to Verheggen, those studies are simply not about the influence of people on the climate. “If you look at another field, such as biology, very few scientists explicitly say in their research that they believe in evolutionary theory. That doesn't mean they don't believe in it, they just investigate something else.”
Fact check NRC Handelsblad
Moreover, the 97% mentioned is not only reflected in Cook's research, but also in various other scientific studies. The variety of studies also shows that the degree of agreement is stronger among groups with more relevant expertise. For example, the consensus is higher among publishing climate scientists than among earth scientists in general.
Baudet is not the first Dutch politician to dispute Cook's conclusions. Earlier, PVV leader Geert Wilders said in a debate that “two-thirds of climate scientists have no position on CO2 harmfulness.” NRC Handelsblad conducted a fact check on this statement by Wilders.
The NRC writes: “According to Wilders, Cook concludes that one third (32.6 percent) of all scientists endorse human influence on the climate and that two thirds do not take a position. But that is not at all what Cook and his colleagues write. They investigated whether they could take such a position from the summary. “
And: “A scientist, for example, researching what the temperature rise in the Arctic means for polar bears, can be very convinced of the human influence on the climate, without naming it. That's not strange at all, Cook writes in a response by email: “You don't expect modern astronomers to explain in their articles that the earth revolves around the sun.”