There's one called 'Darwins Nightmare' which, from memory, was about the introduction of the Nile Perch and the ecosystem/s that couldn't handle it.

There's also the BBC(??) docu called something like "The great global warming swindle"

Penn and Tellers Bullshit episodes that touch on environmental issues...most notably probably being the recycling episode.

Well those are documentaries...whether or not they support your cause is another thing :p

How about 'The Corporation' I haven't seen it in ages but I recall it touched on their detrimental impact on environment.

Make your own documentary on something?

You might also want to ask Moving Pictures.

http://www.vidstumbler.com/vid/830.htm

By the history channel, looks into the possibility of global warming pushing the world into another 'mini' ice age. Its happend before and could happen again. All it would take is the ocean currents changing. Its shows evidence of drastic changes that have happend throughout history, how ancient civilizations have died out from climate change etc.

http://uk.youtube.com/watch?v=8f8v5du5_ag

that is for the 'great global warming swindle' from Channel 4, it's in 8 parts and they are listed under 'more from this user'

good BBC horizon programme on global dimming
http://tinyurl.com/2jwzel

Also a brilliant documentary on the life on this planet is the BBC series planet earth. Countless incredible moments in that series and even better is that it was recorded in HD.

i happened to catch the great global warming swindle tonight.

it is complete bullshit. i haven't seen any other doco's about global warming apart from that, but if they are all that calibre i would give them a miss.

LOL, yeah. It was even shown that they intentionally mislabeled graphs and used outdated data. Pure propaganda plain and simple. It's amazing, you'd think that such blatant deception would only make the global warming deniers look more foolish yet they do it anyway. I guess they are just preaching to the choir, much like creationist propaganda.