Burden of Proof

There's something in the discussions about global warming that I don't get.

The opponents of emission regulation ground their argument almost solely on the fact that scientists can't agree whether global warming will have disastrous effects or only mild effects on the life on planet Earth. The question that puzzles me is, "How on earth have industrialists and politicians succeeded to market the view that the proponents of emission regulation should prove that global warming is harmful?"

The current position in this debate is perverse. Common sense says that if something has even the smallest chance of having disastrous effects on our planet, we'll need to do something about it. The burden of proof is on those who argue that carbon dioxide emissions are harmless.