My main source is
ClimateConcern : The Climate Concern Group (CCG) which is a great group of knowledgable people who find and study some excellent sources.
The only problem with this kind of group is that you have to read everything and we don't always have the time.
This is why I started my pbwiki using many of their postings with their permission. It is organised by subject so may be easier to study what you want.