The scientific consensus on climate change is overwhelmingly strong

A new study finds that the scientific consensus that humans are altering the climate has passed the 99.9% level.

The degree of scientific certainty about the impact of greenhouse gases is now similar to the level of agreement on evolution and plate tectonics, the authors say, based on a survey of nearly 90,000 climate-related studies. This means there is practically no doubt among experts that burning fossil fuels, such as oil, gas, coal, peat and trees, is heating the planet and causing more extreme weather.

One has to parse statistics like this carefully to see exactly what has been measured.

The latest survey of peer-reviewed literature published from 2012 to November 2020 was conducted in two stages. First, the researchers examined a random sample of 3,000 studies, in which they found only found four papers that were sceptical that the climate crisis was caused by humans. Second, they searched the full database of 88,125 studies for keywords linked to climate scepticism such as “natural cycles” and “cosmic rays”, which yielded 28 papers, all published in minor journals.

“It is really case closed. There is nobody of significance in the scientific community who doubts human-caused climate change,” said the lead author, Mark Lynas, a visiting fellow at Cornell University.

As I argue in my book The Great Paradox of Science, it is the consensus arrived at by credible experts who have studied an issue and arrived at the conclusion that there is a preponderance of evidence in favor of the theory that should be determinative. For example, I personally do not have the expertise to evaluate these complex climate models. But I do have confidence in the process by which this consensus was arrived at to support it.

One can always find skeptics to the consensus, especially when there are vested interests with deep pockets who seek to sow doubt so as to paralyze any action that would affect their economic interests. That is especially the case in the US.

The general public does not yet understand how certain experts are, nor is it reflected in political debate. This is especially true in the US, where fossil fuel companies have funded a disinformation campaign that falsely suggests the science is not yet settled, similar to the campaign by tobacco industries to cast doubt on the link between smoking and cancer.

The paper cites a 2016 study by the Pew Research Center that found only 27% of US adults believed that “almost all” scientists agreed the climate emergency was caused by human activity.

Many senior Republicans continue to cast doubt on the link between human activity and the climate crisis as market researchers have advised them to do since at least the presidency of George W Bush. According to the Center for American Progress, 30 US senators and 109 representatives “refuse to acknowledge the scientific evidence of human-caused climate change”. Several big media organisations and social networks also promote climate-sceptical views that have little or no basis in science.

One has to keep hammering away, like I do, that it is the scientific consensus among credible experts that should drive public policy, because it is always possible to produce some anomalous result. That does not mean anything by itself. It is the preponderance of evidence that is important.


  1. atomjz says

    Most climate denialism in the US stems from the American-Christian belief that humans aren’t powerful enough to affect something as massive as the climate, because such a monumental act is “the realm of God” and to believe that we could do such a thing is hubris (or perhaps even heresy). Starting from that, literally no amount of evidence against could sway them: they take it as axiomatic that only their god is powerful enough for such things.

    If they talk about evidence and whatnot, they’re peddling a disingenuous argument that they don’t even believe in. Their true reason is religious, and we waste our time trying to attack their fake, red herring arguments.

  2. Allison says

    Most climate denialism in the US stems from the American-Christian belief …

    I’ve heard all kind of rationalizations for denial, but this is the first I’ve ever heard of this one, so if it exists, it’s new and it’s confined to the fringe elements of Christianity. And I suspect even there, it’s mostly a rationalization to justify doing nothing.

    That lies behind all of the excuses I’ve heard: doing something is too costly or too painful or too big a disruption in their current way of life, so they’d rather believe they don’t need to. Add to that the fact that the effects have been gradual enough that they can be unaware that anything has changed, due to “creeping normalcy.” I don’t think you need to postulate any religious motivation.

  3. garnetstar says

    This has been somewhat funny for me to watch (well, not that amusing), because the first person to propose, then prove mathematically and experimentally, that carbon dioxide causes the atmosphere to warm was a chemist (Arrhenius) in about 1896.

    He was a very foundational figure, Nobel Prize, “father of physical chemistry”, the famous Arrhenius equation still taught in general chem, etc. So, chemists, blindly following their hero, just accepted it without question (few repeated Arrhenius’ experiments or his mathematical proof.)

    I saw a newspaper article from 1912 about how, if we kept burning so much coal, the earth would warm. Then, a newsreel from the 1940’s about burning petroleum causing what was called “global warming”.

    So, when meteorologists, in about the 1970’s and 80’s, were publishing actual data that proved this was happening, chemists all just said “Yeah, we know.”

  4. garnetstar says

    Rob @5, thanks for alerting me to this! Of course, how ironic, the chemists all claim Arrhenius as their hero, and I’d never heard of Foote.

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