The scientists don't like it when economists move onto their patch.
I suspect in many cases economists can do it as well if not better than "real scientists".
The results tell us little more than common sense - uncertainty makes it hard to make exact prediction.
"Uncertainty, Climate Change and the Global Economy"
CEPR Discussion Paper No. DP7024
TORSTEN PERSSON, Stockholm University - Institute for International Economic Studies (IIES), London School of Economics & Political Science (LSE), National Bureau of Economic Research (NBER), Centre for Economic Policy Research (CEPR)
DAVID VON BELOW, Stockholm University - Institute for International Economic Studies (IIES)
The paper illustrates how one may assess our comprehensive uncertainty about the various relations in the entire chain from human activity to climate change. Using a modified version of the RICE model of the global economy and climate, we perform Monte Carlo simulations, where full sets of parameters in the model's most important equations are drawn randomly from pre-specified distributions, and present results in the forms of fan charts and histograms. Our results suggest that under a Business-As-Usual scenario, the median increase of global mean temperature in 2105 relative to 1900 will be around 4.5 °C. The 99 percent confidence interval ranges from 3.0 °C to 6.9 °C. Uncertainty about socio-economic drivers of climate change lie behind a non-trivial part of this uncertainty about global warming.