The Internet is Full of Wisdom: climate change and SF

I'm trying to come up with a list of SF authors who write frequently about climate change, communications technology, or both--and preferably who connect these to justice and societal change. I need the info for an upcoming conference on climate communication, scheduled for August in DC.  (Yes, I know.  But it's our mosquito-infested swamp.  And it will be cool inside!)

I'm quite positive that this conversation already took place at Wiscon and I missed it, probably while I was at the Imaginary Book Club or something.