Predicting climate change????

Climate is way too complex for our simple models...this article is from the New Scientist....

Climate change models, no matter how powerful, can never give a precise prediction of how greenhouse gases will warm the Earth, according to a new study.

The result will provide ammunition to those who argue not enough is known about global warming to warrant taking action.

The analysis focuses on the temperature increase that would occur if levels of carbon dioxide in the atmosphere doubled from pre-Industrial Revolution levels. The current best guess for this number – which is a useful way to gauge how sensitive the climate is to rising carbon levels – is that it lies between 2.0 C and 4.5 C. And there is a small chance that the temperature rise could be up to 8C or higher.

To the frustration of policy makers, it is an estimate that has not become much more precise over the last 20 years.

Ultimately, the papers also illustrate the limits to which models, even those produced by powerful supercomputers, can help politicians make decisions.

"This finding reinforces not only that climate policies will necessarily be made in the face of deep, irreducible uncertainties," says Roger Pielke, a climate policy expert at the University of Colorado at Boulder, US. "But also the uncomfortable reality – for climate modellers – that finite research dollars invested in ever more sophisticated climate models offer very little marginal benefit to decision makers."