World’s Scientists: Global warming could wipe out 1/4 of all species

Environment Colorado

DENVER—Approximately 20-30 percent of plant and animal species are at increasing risk of extinction if the global average temperature increases by another 2.2 to 4 degrees Fahrenheit, according to a major consensus report released today by the Intergovernmental Panel on Climate Change (IPCC).  The IPCC is a United Nations body charged with assessing the scientific record on global warming.

The panel concludes “with high confidence” that human-caused warming over the last three decades “has had a discernible influence on many physical and biological systems.”  While the report warns of increasing droughts, floods, heat waves, water stress, forest fires, and coastal flooding in the U.S., it finds that “many impacts can be avoided, reduced, or delayed” by quickly and significantly reducing global warming pollution.

“This report challenges our leaders in Colorado to take decisive action on global warming,” continued Baker. “We need to listen to the science, and set goals for reducing global warming pollution in Colorado and nationally. The good news is we have the know-how to tackle global warming. Through increasing energy efficiency, expanding renewable energy, and capping and cutting carbon pollution, we can avoid the worse effects of global warming.

Cars and power plants are the largest sources of U.S. global warming pollution, but the U.S. could reduce its emissions immediately using on-the-shelf technologies to improve energy efficiency and shift to renewable energy sources.

Major findings of today’s report for North America include the following:

  • WATER SECURITY: “Warming in western mountains is projected to cause decreased snowpack, more winter flooding, and reduced summer flows, exacerbating competition for over-allocated water resources.”
  • FOREST FIRES: “Disturbances from pests, diseases, and fire are projected to have increasing impacts on forests, with an extended period of high fire risk and large increases in area burned.”
  • HEAT WAVES: Cities that currently experience heat waves are expected to face “an increased number, intensity, and duration of heat waves,” threatening people’s health, particularly that of elder Americans.

“This report reaffirms that Colorado and the West have much to lose unless our leaders take action, “said Matt Baker, Executive Director of Environment Colorado. “Colorado will face decreasing snowpack hurting recreation and tourism economies in the winter and unreliable water supplies ailing agriculture in the summer. Colorado will also see longer, more-intense wildfire seasons.” 

In addition, the report points to large-scale climate events that have the potential to “cause very large impacts,” including the at least partial deglaciation of the Greenland ice sheet, and possibly the West Antarctic ice sheet, raising sea levels by 13 to 20 feet over centuries to millennia.

The IPCC today released the Summary for Policymakers of the second volume of its Fourth Assessment Report, entitled “Impacts, Adaptation, and Vulnerability.”  The second volume synthesizes the peer-reviewed research on the current and predicted impacts of global warming on human health, the environment, and wildlife.  Additional volumes, examining options for reducing future warming and a final synthesis report, are due out later this year.  The full Fourth Assessment Report includes input from more than 2,500 experts worldwide. 

The IPCC was established by the United Nations Environmental Program and the World Meteorological Organization in 1988 with a mandate to assess the state of knowledge on global warming on a “comprehensive, objective, open and transparent basis” and to generate documents that reflect a consensus among those involved.  In 1990, 1995, and 2001, the IPCC issued its prior assessments.

Baker also noted that the report is inherently conservative because it reflects the consensus of hundreds of parties, including industry groups and governments opposed to taking action to reduce global warming pollution.