"[...] all the fuss about global warming is grossly exaggerated. [...] There is no doubt that parts of the world are getting warmer, but the warming is not global. I am not saying that the warming does not cause problems. Obviously it does. Obviously we should be trying to understand it better. I am saying that the problems are grossly exaggerated. They take away money and attention from other problems that are more urgent and more important, such as poverty and infectious disease and public education and public health, and the preservation of living creatures on land and in the oceans, not to mention easy problems such as the timely construction of adequate dikes around the city of New Orleans."
Freeman Dyson, heretic thoughts about science and society.
The scary thing about global warming is that it happens on a timescale that our political institutions aren't equipped to handle, and requires concerted effort by countries that are not equally affected. It's also hard to model and has outcomes that range from "mild disruption" to "Earth turns into Venus".
The precautionary principle suggests that we take it seriously.
Unfortunately I don't remember where I did read it, but I do recall reading a paper rejecting the idea that Earth could follow a runaway green-house effect as on Venus.
I don't know if people seriously see that as a real possibility or not, but at the very least I've never heard any scientist mentioning it seriously.
EDIT: well, apparently it wasn't so hard to find. It's right in the first paragraph of the Wikipedia article about runaway greenhouse effect[1]
"For instance, a “runaway greenhouse effect”—analogous to Venus--
appears to have virtually no chance of being induced by anthropogenic activities."[2]
I very much hope that the worst case is not a Venus like runaway effect. But there are many possible outcomes which for practical purpose for us humans are equally bad. There have been geohistoric events where the temperature rose by 10 degrees, causing most of the eco system to collapse. Eventually life recovered from this, with many larger species gone.
Freeman Dyson, heretic thoughts about science and society.
https://www.youtube.com/watch?v=8xFLjUt2leM
https://www.edge.org/conversation/freeman_dyson-heretical-th...