[jseliger]

But, it boggles my mind why so many people don't believe global warming can be man-made

I used to think the same way, but part of the issue is that most people are not abstract or systems thinkers. They don't perceive abstraction or systems the way many HN readers do or would.

In addition, and related, most people have strong tribal identities that overwhelm their limited intellectual capabilities; Jonathan Haidt's The Righteous Mind is very good on this: https://www.amazon.com/Righteous-Mind-Divided-Politics-Relig... and there are others as well.

Climate change deniers, anti-vaxxers, and other conspiracy theorists share some key underlying traits.

Most of us, including me, also live in our own bubbles. You're likely in a rationalist and data-driven bubble, so you don't see people to whom you'd have explain an entire rationalist and data-driven worldview.