The "97% consensus" has become a conversation-stopper, but understanding where the number comes from reveals a much more nuanced picture.

The most cited source is a 2013 paper by John Cook et al. that examined approximately 12,000 scientific abstracts mentioning "global climate change" or "global warming." The study categorized papers into levels of endorsement of the claim that human activity contributes to climate change. Of papers that expressed a position, 97.1% endorsed human-caused warming at some level.

Here's the critical detail: the study lumped together papers that said humans are the dominant cause with papers that merely acknowledged humans have some effect on climate. Very few scientists of any political persuasion deny that human activity has some influence on climate. The relevant debate — how much warming, how fast, how catastrophic, and what policies make sense — is far from settled.

When the researchers categorized more precisely, only about 1.6% of the papers explicitly stated that humans are the primary cause of most warming since 1950. The gap between "humans have some effect" and "humans are the dominant driver of potentially catastrophic warming" is enormous, and the 97% figure papers over that distinction.

A 2014 study in Environmental Research Letters by Verheggen et al. surveyed nearly 2,000 climate scientists directly and found significantly more variation in views. While most agreed humans are a contributing factor, there was substantial disagreement on the magnitude of human influence, the accuracy of climate models, and the urgency of proposed interventions.

Climate models have a mixed track record. A 2022 analysis published in Geophysical Research Letters compared model projections from the past 50 years against observed temperatures and found that models had consistently overestimated warming, particularly at higher emission scenarios. This doesn't mean models are useless, but it does mean they're not settled scripture.

The phrase "the science is settled" is itself anti-scientific. Science is never settled — it advances through questioning, testing, and revising. The people demanding we "follow the science" often mean "follow these specific policy conclusions" — which is politics, not science.

You can accept that humans affect climate, that warming has occurred, and that we should research cleaner energy, while still questioning doomsday timelines, the accuracy of specific models, and the wisdom of policies that would dramatically increase energy costs for the poorest populations.