The IPCC Report Laser Talk
The Intergovernmental Panel on Climate Change (IPCC) released its 5th Assessment Report (AR5) in 2008.
Note: AR15 was released in October 2018 and an update of this laser talk is under review. The findings summarized below are based on the 2008 report.
The latest assessment finds that there is now 95 percent certainty that human activity is causing global warming.
- Sea levels are likely to rise 3 feet by the end of the century if greenhouse gas emissions continue at current rates.
- The past 3 decades are the hottest since the start of the Industrial Revolution in 1850.
- In the past two decades, the Greenland and Antarctic ice sheets have steadily lost mass, and glaciers are shrinking across the world.
- The concentration of greenhouse gases in the atmosphere has increased to levels unprecedented in the last 800,000 years.
The Role of the Oceans
While the rate of warming has slowed over the past 15 years, this should be viewed as a temporary reprieve, not a long-term trend. Ocean absorption of heat may be contributing to this slowdown.
Thomas Stocker, a co-lead on the IPCC report said, “That doesn’t mean that the ocean saves us from global warming. It means that there would be much more powerful (shorter-term) global warming if it wasn’t for the ocean.”
The report outlines four scenarios for warming throughout the century. There is only one scenario that prevents temperature increases from exceeding the 2°C degree-threshold scientists say is manageable. That scenario is one in which carbon emissions are substantially reduced. The report states that there is a limit to the amount of carbon dioxide we can safely emit. At current rates, we’ll exceed this limit by 2040.