His research is on the physics of clouds and their role in the climate system.
But at this point, part of it also just depends on exactly how sensitive the climate system turns out to be.
A broad range of evidence shows that the climate system has warmed.
Since 1972, our understanding of the climate system has improved.
What don't we know about the role of water in the climate system?
Snow cover, scientists say, is an important element of the Earth's climate system.
Human activities have had a number of effects on the climate system.
But what if the earth's whole climate system were to snap warm like that?
Interactions elsewhere in the climate system are just beginning to be understood.
In addition, the global climate system depends on its stability.