Question: What argument is used by the 3% of scientists who don’t agree that climate change is happening/human-caused?
Nadir’s Answer: My impression is that this “3%” generally consists of scientists who acknowledge that CO₂ is rising due to human activities, and who also acknowledge that this rising CO₂ will cause some global warming, but who disagree on the amount of warming it will cause. Such scientists might be suspicious of estimates from computer climate models due to their complexity, and may have other explanations for some of the warming we’ve observed so far, such as natural fluctuations. Such skepticism and formulation of alternative hypotheses is natural, and is moreover an essential part of a healthy scientific enterprise. But the accumulated evidence, as documented in ever-expanding reports by the IPCC and other bodies, continues to point to human-emitted CO₂ as the main driver of observed climate changes.