anyone claiming that I'm biased in describing climate change as driven by humans is actually experiencing what Daniel Stone (in our subscribers-only interview) called "affective polarization:" "So if you dislike someone, you're not going to admit they're right, even if the evidence is really clear they're right. It's sort of another example of how polarization drives inefficiency. It could stop us from implementing policies that we would agree on otherwise."

We know what factors drive the Earth's heating/cooling cycles. We know that our planet receives energy from the sun, radiates heat to the atmosphere, and that our atmosphere has certain "greenhouse gasses" that re-radiate that heat back to Earth. In other words, we know that heating/cooling cycles are driven by changes in energy coming in (solar cycle and Earth orbit), changes to the Earth's surface (ice cover, plant cover, and other life) that affect energy going out, and changes to the Earth's greenhouse gasses (concentration of CO2, CH4, water vapor, and others in our atmosphere) that affect energy retention. We can measure those factors today. We have a very good understanding of the solar cycle and our Earth's orbit. We have a very good understanding of our planet's surface. And we have a very good understanding of historical changes to the atmosphere, through ice core data and direct atmospheric measurement. Of the factors that contribute to warming, it's very apparent that only greenhouse gasses have increased over the past century to any significant degree (and the degree of increase is very significant). We are aware of what's causing those factors to increase. The long-lived greenhouse gasses in our atmosphere that keep our planet warm eventually return to the earth, and again to the atmosphere, through a process called the carbon cycle. Many things contribute to this cycle, and there are a lot of great arguments that support that the excess carbon is anthropogenic. One of the best arguments is that the proportion of carbon isotopes in the atmosphere is consistent with an increase in the carbon from organic matter (i.e. burned fossil fuels), and that the increase of these isotopes began with the Industrial Revolution and has increased ever since. The Earth is getting warmer. There is essentially unanimous consensus that the Earth has been warming over the past 100 years.

I think suggesting that the identifiable excess emissions from human activity are not causing the definite increase in global warming is kind of like saying, "sure, there have been a lot more deaths from car accidents after the invention of the automobile, but hey — who can say if that has anything to do with cars? People have been dying in accidents forever."