What Does the 97% Consensus on Man-Made Climate Change Really Mean?
Talking about science is my life. I’ve been doing it long enough to know I’ll regularly face opposition from people whose beliefs don’t jive with the facts, especially considering that issues like evolution, vaccines, and man-made climate change come up quite often in my videos.
I can handle that. And I don’t exclude these voices of disagreement, even if they are wrong or badly misinformed. Instead, I do my best to welcome everyone in, to get people to, even if just for a moment, look at the world from a scientific point of view. The universe looks much better from here, trust me!
On the It’s Okay To Be Smart YouTube channel, I’ve made a couple of videos about climate science. One lays out the basics of climate science, and the other examines why people don’t believe in it. Check ‘em out if you haven’t already:
I don’t know what’s up, but I’ve had climate science deniers descending on my YouTube comment sections like flying monkeys swarming a Kansas girl. These passionately pugnacious people have a list of bad-but-confusingly-complex arguments as long as your arm, but there’s one in particular that I’m super tired of hearing: The claim that the “97% consensus” on climate change is a hoax, or has been debunked. Everyone from presidential candidates to basement bloggers have trotted this one out, and it’s time we put it to rest.
Rest assured, 97% of scientists really do agree that climate change is real and humans are a major cause.
This statement is true. And I’m going to tell you why it’s true, but first you have to promise not to just say “Nuh uh! No it isn’t!!!” because if you’re going to start off by declaring that up is down or salt is sugar, we’re not going to get very far and someone’s gonna leave with a bad taste in their mouth. To see eye to eye with people who disagree with us, we have to agree to live in the same non-imaginary universe.
Last week, a group of scientists led by John Cook published a new study of climate consensus, and guess what? ~97% of scientists really do agree that humans are causing recent climate change! It’s not debunked! Rather, it remains fully bunked!
Cook’s is the latest of multiple studies between 2004 to 2016 looking at the level of agreement that humans are causing recent global warming and broader climate change. Using a variety of methods, these many studies have shown consensus between 90-100%, and they have shown it consistently. A consensus on consensus!
What Cook did was look at the abstracts of climate science papers (the abstract is a sort of short introductory summary of a paper and its findings) and use that abstract to gauge whether the scientist who wrote it supports the idea that humans are causing climate change. They did this with thousands of papers written by thousands of scientists from around the world published over more than a decade. Cook and his team then went a step farther and actually surveyed the scientists themselves to make sure they were capturing true opinions and not just misreading abstracts.
When you look at the scientific research, the sum total of papers that express a position on what or who is causing climate change, 97.1% of them agree that it’s humans. Just 1.9% reject the idea that humans are causing it, and 1% are uncertain.
Very talented climate deniers will point to that and say “Ok, that’s fine, but the consensus goes way down when you include papers that don’t take a position on the cause of climate change!” These people want you to believe that a paper that doesn’t specifically mention a cause for climate change by default disagrees with humans causing it.
What that really means is that the consensus is so strong, and it has been that way for so long, that most climate scientists don’t bother writing it in every paper they write. I mean, imagine if every biology paper had to say “DNA, which we strongly believe is the information molecule responsible for genetic inheritance…” or if physicists had to constantly repeat “We believe that gravity is a warping of space and time due to massive objects…”
I agree. It is ridiculous. The scientific community is certain enough that humans are causing climate change that they don’t even bother reminding each other of it anymore.
I wish we didn’t have to remind each other either. Maybe then we’d be further along in reversing it and adapting to our changing world?
As a result of these campaigns of doubt (looking at you, here, YouTube commenters), the public believes that scientists are much more divided on the issue than they really are (only 57% of the public thinks scientists are in agreement). The boatloads of bits and bytes that have been wasted trying to claim that scientists don’t actually agree on what’s causing climate change has had real consequences. Just look at this week’s news about the Great Barrier Reef.
I know, Ariel. It makes me sad too.
What’s most interesting is Cook found that the more climate-specific expertise a scientist had, the more likely they were to support the consensus. Essentially, people who know the most about Earth’s climate agree even more that we’re behind recent warming.
John Cook and his fellow authors recently did a Reddit AMA, where they answered a ton of questions about what the 97% number means and why consensus is a thing worth paying attention to in science. You should check it out.
If you still find yourself disagreeing with scientists and doubting humanity’s role in climate change, that’s your choice. I think it’s a bad choice, and there’s a LOT of evidence to back me up, but you’re free to believe that.
You’re just going to have to stop using the 97% argument as a reason.
