Forecasting is very difficult, especially when it involves the future.
Saturday, 15 December 2012
IPCC AR5 draft report release - the bottom line
An expert reviewer of IPCC AR5 (Assessment Report 5) has released the entire draft on the internet. it contains a graphic showing the global temperature "projections" from climate model runs from the previous four reports. Put simply, the graphic destroys any claims of continuous warming of the global climate since the publication of the FAR (First Assessment Report) in 1990. it destroys the claim made in a recent paper that the global temperature trend since then has vindicated the accuracy of projections from that FAR. It supports the observation of sceptics (and some enlightened and open-minded climate scientists) that global temperature has not increased this century, and that actual temperature data shows a trend well below IPCC projections. It is clearly the "elephant in the room" for proponents of CAGW (Catastrophic Anthropogenic Global Warming) and warmists and doomsayers in general.
The vertical black bars indicate the possible range of error in observations (square black dots) from the GISS temperature dataset; it's quite clear that there's been no increase in global temperature since 1998 and that temperatures are trending below the model projections from all four reports (the coloured bands). It should be obvious to anyone that climate models don't model the global climate; in principle they can't - the climate is a chaotic stochastic system that doesn't lend itself to modelling as stated in an early iPCC report, but that didn't stop climate modellers applying their magic computer code to predicting the unpredictable. It should be clear to anyone who studies the science in any detail that while there is an anthropogenic effect, it's quite small, and is highly unlikely to lead to any substantial warming of the global climate. It should also be clear that while CO2 is, and must be, a climate driver its effect is relatively small, and it's predicted effect on climate vastly overblown. Whatever the conclusions are in the published AR5, due next year, mankind is having no great influence on global climate.