It’s about the time for the next UN expert climate report to be published, but the leaked excerpts are already causing the usual flurry of predictable, polarized political ranting that accompanies any scientific discussion of our climate. Let’s look at the leaked excerpts from the 5th Intergovernmental Panel on Climate Change put together by the world’s top climate scientists — whose last climate report came out in 2007 — and then we’ll get into the politics, which has hijacked this “debate”.
The overriding message of the report is the most politically polarizing: There is a 95 percent chance that humanity is the key cause of global warming. (Up from a 90 percent chance in the group’s 2007 report).
Other key findings include:
- Emissions at or above current rates would induce changes in all components in the climate system, some of which would very likely be unprecedented in hundreds of thousands of years.
- Carbon dioxide emissions from the burning of the fossil fuels that power the world are the main cause of global warming.
- “Changes are projected to occur in all regions of the world, with a significant impact on sea levels, ice and snow and acidification. There is stronger evidence that the rate of sea level rise has increased during the past two centuries, and ice sheets and glaciers are losing mass, while sea ice cover in the Arctic is decreasing. Global sea level will rise during the 21st century, potentially by over three feet. It is very likely that the Arctic sea ice cover will continue to shrink and thin.
- Many of these changes will persist for centuries.
- Each of the past three decades has been warmer than ALL preceding decades since 1850.
- It is extremely likely that human influence on climate was responsible for more than 50 percent of the observed increase in global average surface temperature from 1951-2010.
- On the plus side, if atmospheric CO2 levels double, we could see warming of 2.7 degrees, rather than the earlier predicted 3.6 degrees.