Highlights of the fifth report by the Intergovernmental Panel on Climate Change

The time has come: the new IPCC report is here! After several years of work by over 800 scientists from around the world, and after days of extensive discussion at the IPCC plenary meeting in Stockholm, the Summary for Policymakers was formally adopted at 5 o’clock this morning. Congratulations to all the colleagues who were there and worked night shifts. The full text of the report will be available online beginning of next week. Realclimate summarizes the key findings and shows the most interesting graphs.

Global warming

It is now considered even more certain (> 95%) that human influence has been the dominant cause of the observed warming since the mid-20th century. Natural internal variability and natural external forcings (eg the sun) have contributed virtually nothing to the warming since 1950 – the share of these factors was narrowed down by IPCC to ± 0.1 degrees. The measured temperature evolution is shown in the following graph.

Figure 1 The measured global temperature curve from several data sets. Top: annual values. ​​Bottom: averaged values ​​over a decade.

Click here to read the full story at Real Climate website.

Click here for the 2 page summary of the headline statements by the IPCC in PDF format.

About the author:  A physicist and oceanographer by training, Stefan Rahmstorf  teaches physics of the oceans as a professor at Potsdam University and conducts research on the role of ocean currents in relation to climate change at the Potsdam Institute for Climate Research.  Rahmstorf is a member of the Advisory Council on Global Change of the German government and of the Academia Europaea. He is a lead author of the paleoclimate chapter of the 4th assessment report of the IPCC.

In 1999 Rahmstorf was awarded the $ 1 million Centennial Fellowship Award of the US-based James S. McDonnell foundation.