National Call to Action on Global Warming

The impacts of global warming on human and natural systems are now being observed nearly everywhere. In 2007, the Nobel Prize-winning U.N. Intergovernmental Panel on Climate Change (IPCC) predicted serious risks and damages to livelihoods, human infrastructure, societies, species, and ecosystems unless future warming is reduced. So far this decade, emissions, warming, and impacts, such as ice melt and sea level rise, have all been at the upper end of IPCC projections.

More recent findings since the publication of the latest IPCC assessment suggest that even more urgent action may be needed. In 2008, for example, the U.S. National Snow and Ice Data Center announced that summer Arctic sea ice had reached the second-lowest level ever recorded, following the record-breaking 2007 summer. This observed rapid Arctic melting is already far outpacing IPCC worst-case scenario projections. Two years ago, the IPCC projected that Arctic sea ice could disappear almost entirely by the latter part of this century. Now, scientists from NASA and other agencies warn that Arctic summers could be nearly ice-free within the next five years.