A bunch of academics, supported by an editorial staff based at Boston U, have put together the Encyclopedia of Earth. The site describes itself as "everything earth, articles by experts, ever expanding" and, based on an admittedly cursory investigation, that description seems apt. Rather than staking out anything that could be characterized as a position on either extreme, EoE provides well-reasoned, well-sourced data and analysis on a wide range of topics relating to the only planet we've got.
Funding for the site comes primarily through the National Council for Science and the Environment, and is fully tax-deductible. NCSE, itself, boasts an informative site and an impressive list of funding sources -- most of it is foundation money, with significant slices from both government and higher ed; only 2% comes directly from corporations.
At various meetings, both on campus and in the local community, I get asked for good sources of information by people who believe there's a sustainability crisis, but don't believe they're well-positioned to back up their impressions. I also like to refer climate cynics to information sources which will challenge their current base of misunderstanding (particularly sources which don't actively invite dismissal as 'enviro-Nazi propaganda'). I'm thinking that EoE may serve well in both instances. I'm also thinking it would be a good reference link for a wide range of introductory-level (at the very least) sustainability courses.