How can you predict global warming if you can’t predict rain?
Some say climate change is part of a complex natural cycle – so complex, in fact, that it can’t be forecast. Are current climate models reliable?
By Peter N. Spotts Staff writer of The Christian Science Monitor
To those of us who are not climate scientists, it may come down to this: How can we be so certain what the climate will be like a century from now if you can’t get a decent weather forecast more than two weeks ahead? In the end, isn’t climate change just too complex?
True, weather forecasters are fallible, and there is no planet out there similar to Earth so we can truly gauge the effect human activity is having on our climate. But climate researchers are increasingly confident of their models and simulations. Besides, some argue, predicting the weather is tougher than predicting the climate, and scientists have been working on perfecting climate models for more than a century.
In a chilled, windowless room here at the National Oceanic and Atmospheric Administration’s Geo physical Fluid Dy namics Laboratory (GFDL), a supercomputer is furiously crunching numbers in an attempt to mimic Earth’s climate system.
It’s a tool Svante Arrhenius could only dream about. In 1896, the mustachioed Swede gave the first detailed description of carbon dioxide’s warming effect on climate. He had to solve some 10,000 equations to do it. Armed with his crude climate model, he reckoned that if the amount of CO2 in the atmosphere doubled, global average temperatures might rise by up to 9 degrees F. Today’s modelers say his estimate is high – but not by much.
Today’s climate models try to simulate more than one feature – more than Arrhenius’s CO2 – of the climate system and in greater detail. They’re still far from perfect and miss important processes.
Read the full article here.
Hat tip to Marc Morano.