A former engineer looks at how he went about changing his mind on global warming, and how people evaluate the truth. In general it is not rational at all–it has to do with evaluating how much you trust the source of the information, not the information itself. Which is why people who don’t want to accept the truth of the dangers of tobacco or global warming attack the motives of the people talking about these things rather than the scientific data itself.
Though they differ on the details, the one thing all of these experts agree on is that just telling folks the facts — temperatures are going up, seas are acidifying, and the most likely reason is people burning fossil fuels — doesn’t move the needle on climate opinion. Instead, ears seem to open only when people they trust ask them to take a second look at something they thought disagreeable.