SPIEGEL: Does this throw the entire theory of global warming into doubt?
Storch: I don't believe so. We still have compelling evidence of a man-made greenhouse effect. There is very little doubt about it. But if global warming continues to stagnate, doubts will obviously grow stronger.
SPIEGEL: Do scientists still predict that sea levels will rise?
Storch: In principle, yes. Unfortunately, though, our simulations aren't yet capable of showing whether and how fast ice sheets in Greenland and Antarctica will melt -- and that is a very significant factor in how much sea levels will actually rise. For this reason, the IPCC's predictions have been conservative. And, considering the uncertainties, I think this is correct.
SPIEGEL: And how good are the long-term forecasts concerning temperature and precipitation?
Storch: Those are also still difficult. For example, according to the models, the Mediterranean region will grow drier all year round. At the moment, however, there is actually more rain there in the fall months than there used to be. We will need to observe further developments closely in the coming years. Temperature increases are also very much dependent on clouds, which can both amplify and mitigate the greenhouse effect. For as long as I've been working in this field, for over 30 years, there has unfortunately been very little progress made in the simulation of clouds.
SPIEGEL: Despite all these problem areas, do you still believe global warming will continue?
Storch: Yes, we are certainly going to see an increase of 2 degrees Celsius (3.6 degrees Fahrenheit) or more -- and by the end of this century, mind you. That's what my instinct tells me, since I don't know exactly how emission levels will develop. Other climate researchers might have a different instinct. Our models certainly include a great number of highly subjective assumptions. Natural science is also a social process, and one far more influenced by the spirit of the times than non-scientists can imagine. You can expect many more surprises.
http://www.spiegel.de/international...lems-with-climate-change-models-a-906721.html