Nah, it's far worse than those conspiracies. Just look at published science. You're getting confirmatory studies coming out of every field-from geology to ecology scientists are noting the impacts of climate change and confirming them.
Every hard science agrees... this conspiracy involves literally millions of people, who mostly despise each other and are in bitter competition with each other over grant money, recognition and publishing opportunity...yet somehow all of them happily collaborate on a hoax which they stand to gain almost nothing from. 
Doing it for grant money makes no sense ! The scientist who definitively disproves climate change (any aspect of it - up to and including "already costs us trillions a year and will soon cost far more than the annual GDP of the world") is guaranteed a nobel prize.

Who wants a ten-thousand dollar grant, most of which you can't keep, when you can get a million dollar prize by not joining the conspiracy ?