Climate Changing Faster Than Predicted

Greenhouse gas levels are rising and the climate is changing much faster than predictions in the most recent report from the Intergovernmental Panel on Climate Change (IPCC), according to a new report from The Climate Institute in Australia.

"Evidence of Accelerated Climate Change" says the IPCC's last report, issued earlier this year, was based on scientific data from only up until mid-2006. Since then, however, much more evidence has emerged indicating that the IPCC's predictions, as serious as they already are, might be unrealistically optimistic.

"These suggest that the IPCC assessment is underestimating the risks of adverse impacts due to increased warming during this century and that impacts previously considered to be at the upper end of likelihood are now more probable," the report's authors stated. The authors also expressed concern the IPCC might not have put enough focus on events that, while low in probability, could have dramatic global consequences.

These could include events like a rapid collapse of ice sheets that could cause sea levels to rise by several meters in a century -- "enough to transform global coastlines" -- or a "catastrophic" release of carbon from icy hydrate reservoirs below the ocean floor.

The Climate Institute report pointed to several areas in which new research raises questions about the latest IPCC assessment:

Carbon dioxide emissions grew by more than 3 percent a year between 2000 and 2004, a rate that exceeds the "most fossil fuel-intensive emissions scenarios" used by the IPCC;

The extent of Arctic sea ice has shrunk more than any previous climate models suggested, with 2007 seeing the lowest levels yet recorded. That suggests an ice-free Arctic Ocean could become reality much earlier than the IPCC's prediction of between 2050 and 2100;

And the ability of land and seas to absorb carbon dioxide from the atmosphere is declining more quickly than projected by the IPCC. "These sinks are important since roughly half of the anthropogenic carbon dioxide emissions are absorbed by land and oceans," the report stated.

"Managing the risk of climate change requires consideration of those consequences that we understand and those where there is the potential (particularly if it is large) for impacts, even though at this stage the probability of the occurrence is unknown," the report's authors concluded. "This paper suggests that there exists evidence that the IPCC process may have led to an underestimation of the risk of greater warming and that the impacts of climate change are occurring more rapidly then previously projected."

The Climate Institute, "New Report Shows Climate Change Faster Than Predicted." URL: (http://www.climateinstitute.org.au//index.php?option=com_content&task=view&id=120&Itemid=40)