The Intergovernmental Panel on Climate Change (IPCC) just released a new report on the state of the climate. As a scientist, I certainly have my own opinions on the matter. However, I thought for today, I'll just post some of the major points of the report as collated by the National Parks Service.
2. Globally averaged land and ocean surface temperature shows a warming of 0.85 ºC [90% confidence interval 0.65 to 1.06ºC] over the period 1880–2012. (IPCC SPM-3)
3. The frequency or intensity of heavy precipitation events has likely increased in North America and Europe. (IPCC SPM-4)
4. The rate of sea level rise since the mid-19th century has been larger than the mean rate during the previous two millennia. Over the period 1901–2010, global mean sea level rose by 0.19 m [90% confidence interval 0.17 to 0.21 m] (IPCC SPM-6)
5. Atmospheric concentrations of greenhouse gases have increased to their highest levels in the last 800,000 years. Fossil fuel emissions, deforestation, and other human activities have caused 40% of the increase since 1750 (IPCC SPM-7).
6. Natural factors account for only a small contribution to observed warming. It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century. (IPCC SPM-12)
7. If humans do not reduce greenhouse gas emissions, global average temperature may increase 1.1 to 4.8ºC by 2100, compared to the 1986-2005 average (IPCC SPM-15), extreme precipitation events would very likely become more intense and more frequent (IPCC SPM-16), and global average sea level may increase 0.32 to 0.82 m (IPCC SPM-18).
The situation is grim, and I'm sure there will be more discussion about this in the news and throughout the scientific and political world. Here is the citation for the full report and a link to find out more about the group and this year's meeting.
Intergovernmental Panel on Climate Change (IPCC). 2013. Summary for Policy Makers (SPM). Climate Change 2013: The Physical Science Basis. Twelfth Session of IPCC Working Group I, Stockholm, Sweden. September 27, 2013.