The summary of the fifth Intergovernmental Panel on Climate Change (IPCC) report has been released, and it confirms that climate change is real, dangerous, and caused by us. More than 97% of science papers that take a position on climate change support this conclusion.
This unprecedented level of scientific certainty has not stopped legions of pundits from rejecting evidence, questioning scientists' motives and qualifications, and proposing ever-sillier ideas that scientists themselves are part of a vast international green conspiracy.
If only that were true.
Surprisingly, these techniques often work. While the overwhelming majority of scientists accept the science behind climate change, only 54% of Canadians believe it poses a major threat. Part of this rejection is due to a healthy skepticism; you really can't believe everything that you read. There are people who aim to mislead, and it happens all the time. So how can the public separate the wheat from the chaff?
A great first step is to insist on forming opinions that are based on peer-reviewed research. To understand why this matters, we first need to understand what it means to have a study subjected to peer-review.
When scientists conduct research, they communicate their findings to other researchers through publishing their work in peer-reviewed journals like Science, Nature, and The Lancet. For this to happen, scientists must fully disclose their research methods including how they conducted the study, where the data came from, and on what basis they drew their conclusions. They also have to report who is funding the work, and in most cases they must make their data available to others to verify that the math behind their results were correct. They then have to convince several anonymous experts in the field (who serve as reviewers) that their work has merit.
Reviewers will often find flaws with the work. If the researchers cannot adequately correct these flaws, the study is rejected, and does not get published in the journal. This is the process that scientists have followed since the days of Darwin, and it applies whether you're discovering planets, studying bacteria, or researching drug policy.
No other type of literature is subject to the same level of scrutiny as one that has gone through true peer-review. That's the difference between a person (however respected they may be) voicing an opinion, and a researcher reporting the results of a study. The former may be basing their opinion on anything from a real science article to something scrawled onto a bathroom stall at the local pub -- there is simply no way to know. By contrast, real scientific literature is at least subjected to a rigorous review process.
However, the fact that a paper is peer-reviewed does not make it flawless. Papers with errors can and do get published. In addition, in the rare occasion that a researcher fabricates results, it is difficult for the peer review process to pick up the deception (though it is almost always caught soon after publication).
However, science is inherently self-correcting -- other researchers can publish rebuttals, or demonstrate that a different view is better supported by evidence. Those rebuttals must meet the same standard of review, ensuring that the debate doesn't devolve into volleys of unsubstantiated accusations that prove nothing. Peer review is not perfect, but it is the best system we have.
This is why we can have confidence in the IPCC report. Every line of this document has been scrutinized, reviewed, and subject to criticism by experts across the world. It contains more than 9,200 citations of other peer-reviewed literature, and with more than 50,000 reviewer comments there have been suggestions that this may be the most heavily reviewed document in human history . Whether we choose to accept the evidence provided or not, there is no doubt that the process that produced this report was objective and sound.
Climate change is real, and we need to do something about it. But don't take my word for it: ask to see the studies. A legitimate researcher will show you their peer-reviewed work, and will be happy to do so. A fraud won't. It's that simple.