Today, the Intergovernmental Panel on Climate Change (IPCC) released the first part of its fifth assessment report (known in the field as AR5). The report represents, in many respects, the verdict on what we know about climate change from the planet’s leading climate scientists. Over 800 experts representing 85 countries have spent the past several years reviewing the climate research happening all around the world and distilling the results into a series of reports that reflect the combined wisdom of the field. Their verdict: man-made climate change is a reality.
Deniers have a habit of reading these reports with electron microscopes looking for any details they can rewrite to fit their message with the imagination of a Stephen King novel. To judge from early indications, this year’s report is no different. Expect to see places like the Wall Street Journal or the Daily Mail fill their front pages with claims AR5 shows climate change isn’t happening and quotes out of context about temperature sensitivity and a pause in global warming. These are smoke and mirrors designed to detract our attention from the core facts and nothing more.
The truth is, for those of us who don’t spend our lives in research labs, there’s only one number that matters: 95 percent. Because it really matters. When scientists got together and released the second IPCC report in 1995, they were about 50 percent certain that humans were driving climate change. Today, that number is 95 percent.
Think about this number. Let it sink in. What makes the number stand out is that it doesn’t come from flag-burning protesters in the streets, climate advocates, or professional provocateurs with an agenda. It comes from climate scientists. Who, by their nature, are quite a conservative bunch when it comes to conclusions—especially collective conclusions. Unlike statements from oil companies and Glenn Beck, their work has to hold up to public scrutiny and reflect the truth to the very best of their knowledge. After all, their reputations and careers, and integrity are on the line.
Then there’s the fact that the report’s findings reflect the unanimous agreement of hundreds and hundreds of scientists and government officials, many with vastly different political ideologies and world views. Think about this: when was the last time you could get even 20 people in a room to agree on anything more complicated than the color of traffic lights?
That such a large, diverse, and risk-averse group is able to state with 95 percent certainty that we are causing climate change tells you everything about the fundamental reality of the crisis. Climate change is real. It’s happening now. It’s human-caused. So when you read or hear anti-science deniers claim climate change isn’t happening or it’s not caused by anything we’re doing, remember the overwhelming majority of real experts agree on those three simple truths: and there’s mountains of data behind those truths.
And they’re more certain than ever.