As an update to the latest IPCC report from the UN, they’ve released the Climate Change Science Compendium 2009. It “is a review of some 400 major scientific contributions to our understanding of Earth Systems and climate that have been released through peer-reviewed literature or from research institutions over the last three years”.
A lot has changed in the last three years. The picture is becoming clearer and clearer, and it’s not pretty.
pundit.co.nz has an excellent summary, and here are a few tidbits
Scientists believe that our greenhouse gas emissions to date have already committed the world to average warming of 2.4 degrees celsius – surpassing the two degrees previously identified as a dangerous risk.
The IPCC’s worst-case emissions scenarios have been exceeded. Man-made emissions have risen 38 percent above 1990 levels. They rose on average 3.5 percent per year for the period 2000-2007, an almost four-fold increase on the previous decade’s average of 0.9 percent per year.
The Arctic could be ice free in summer within 20 years, not the waning years of this century as had previously been thought.
A plausible range for global average sea level rise of 0.5 to 2.0 metres by 2100 is suggested, due to thermal expansion and ice melt – much more than the upper limit of 59 centimetres previously predicted by the IPCC.
Modelling shows that a 50 centimetre rise would produce tidal events every day that now occur once a year, and events expected once during the whole of the 20th century will occur several times every year by 2100.
This is pretty stark. Although it’s not surprising that the official IPCC reports have turned out to be very conservative, when every single line has to be agreed upon by so many people. Naturally, only the most common-denominator science is allowed through.
What do you reckon it take for Nick Smith to get real about this issue? If not this, what will?