Because any place that involves technological discussions attracts a number of self-styled "objectivists" and libertarians who can't cotton to the idea that collective selfless behavior is needed to solve any problem.
I would dare to say that there's much, much more than ideology here. There's an awful lot of propaganda on Global Warming. The facts that are presented are, in a way, manipulated to scare the masses. For me it's more than ideology, it's a matter of principle. I would like to see good, honest and open scientific debate on this topic, and that seems to be impossible. Anyone who questions the validity of the global warming predictions is labeled as a crackpot. This is very dangerous. This kind of dogmatic view is rather similar to the Inquisition.
If everybody had studied the global climate in detail and had arrived at the same conclusions, then the fact that everybody thinks the same way would not be dangerous. After all, everybody thinks the Earth is approximately ellipsoidal, and everybody can measure it. However, very few people have studied the climate in detail, and due to this herd movement, any scientist who questions the predictions the most pessimistic arrive to is attacked. This is unacceptable.
If everybody had studied the global climate in detail and had arrived at the same conclusions, then the fact that everybody thinks the same way would not be dangerous. After all, everybody thinks the Earth is approximately ellipsoidal, and everybody can measure it. However, very few people have studied the climate in detail, and due to this herd movement, any scientist who questions the predictions the most pessimistic arrive to is attacked. This is unacceptable.