[starlust2]

Compared to the expense of failed crops? Mass migration of all humans to the northern most reaches of Canada?

I really don't think you get it. If temperatures rise enough, most of Central and North America won't be uninhabitable. The parts that aren't underwater will be too hot and parched. We won't be able to grow crops or desalinate enough water when the clouds and rain disappear (yes that will happen).

The 3 days of intense heat here in Portland left plants all around my yard scorched and half dead. Just 3 days. Imagine that happening regularly around the world.

[kyteland]

Climate change doesn't necessarily mean everything will get hotter and scorched and we all have to move to northern Canada. It means things will be different than they were historically in ways we don't necessarily understand that well. There's plenty of evidence that past warming periods caused the Sahara to green by shifting the African monsoon patterns farther north on the continent.

https://en.wikipedia.org/wiki/African_humid_period

Current climate change seems to be messing with the jet stream in North America in ways that diverge from historical data. Then you get things like your yard scorching in Portland this summer and my hedges freezing and dying in Austin this winter. We've built a huge amount of infrastructure on assumptions about local weather patterns that may now be invalid.

[JKCalhoun]

> won't be uninhabitable

I think you have a typo.