Effective altruism (EA) is a big topic here on LessWrong, but for some reason I seldom see environmental causes get more than a trivial mention here. 

Can anyone recommend me some good reading about environment-focused effective altruism?

(If anyone can explain why no one on LW seems to talk about it, I am also interested. Maybe LW is dominated by Silicon Valley types who tend to be not very environmental. I don't know.)