The Intergovernmental Panel on Climate Change is preparing to release their 2013 Climate Change report on September 27th. The report will be the first by the IPCC since 2007.
Among other climate change issues, the report is expected to address the slowed rate at which the earth’s surface is heating despite increasing greenhouse gas emissions. This trend has been an arguing point for climate change skeptics who deny the link between human-emitted emissions and rising global temperatures.
"I think to not address it would be a problem because then you basically have the denialists saying, `Look, the IPCC is silent on this issue,'" said Alden Meyer of the Union of Concerned Scientists.
While global temperatures are rising, the rate at which they are doing so since 1998 has been about half the average rate since 1951. Scientists of the IPCC will point to several reasons for the change in the trend in their report.
The main explanation given by the IPCC is that ocean waters are absorbing much of the heat. The panel says it is only a matter of time before heat stored in ocean waters returns to the atmosphere.
"The heat is not missing," said University of Victoria climate scientist Andrew Weaver. "The heat is there. The heat is in the ocean."
"Energy will hide out in the ocean for a while before it pops out into the atmosphere," said Princeton University climate scientist Michael Oppenheimer.
Scientists also point out that 1998 was an exceptionally warm year, so any graph using 1998 as a starting point for displaying rising temperatures will appear relatively flat. The trend over the last two decades still displays a steady rise in global temperatures. The decade from 2000-2010 was the hottest on record. The second hottest decade on record? 1990-2000. Every year since 2000 has been warmer than the year 2000.
IPCC scientists also look at record low sea ice levels in 2012 in their report. In the last 100 years, sea water levels have risen by 7.5 inches – an unprecedented leap for such a short amount of time.
In their 2007 report, the IPCC projected sea levels to rise by 7-23 inches by the end of the century. The IPCC increased their projections in the latest report, now expecting levels to rise by 10-32 inches.
In 2007, the IPCC said it was “very likely” that human influence caused more than half of the rising global temperatures. In the upcoming 2013 report, the IPCC now says it is “extremely likely” that humans have caused more than half of global temperature increases.
IPCC Chief Rajendra Pachauri spoke recently about the goals of the panel’s upcoming report.
"There will be enough information provided so that rational people across the globe will see that action is needed on climate change," Pachauri said. "We are doing our job and we are reasonably confident that rational people in government and all over the world will see the merit of the work that has been done.
"We have done everything humanly possible to ensure that every stage of drafting, every stage of comments and expert reviews carried out, that we look for any potential error or any source of information that might not carry the highest levels of credibility.”