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Climate report charts “highway to extinction”
March 31, 2007
Staff and wire reports
Updated April 10
As the world gets hotter by degrees, millions of poor people will
suffer from hunger, thirst, floods and disease unless drastic action is taken,
scientists and diplomats warned April 5 in their bleakest report ever on
global warming.
The report maps out the effects of global warming with every degree of temperature rise, most of them bad.
It is the second of four reports coming this year from the Intergovernmental
Panel on Climate Change, a United Nations network of 2,000 scientists.
There’s one bright spot: A minimal heat rise means more food production in northern regions of the world.
However, the number of species going extinct rises with the heat, as does the number of people who may starve, or face water shortages, or
floods.
Some scientists are calling this degree-by-degree projection a “highway to extinction.”
But “on this highway there are many turnoffs,” University of Victoria climate scientist Andrew Weaver said
of the chart of results from various temperature levels. “This is showing you where the road is heading. The road is heading toward extinction.”
Weaver is one of the lead authors of the first report, issued in February.
While humanity will survive, hundreds of millions, maybe billions of people may not, according to the chart—if the worst scenarios happen.
“Major extinctions around the globe”
The report says global warming has already degraded conditions for many species, coastal areas and poor people. With a more than 90 percent level of confidence, the scientists in the draft report say man-made global warming “over the last three decades has had a discernible influence on many physical and biological systems.”
But as the world’s average temperature warms from 1990 levels, the projections get more dire. Add 1.8 degrees Fahrenheit—1 degree Celsius is the calculation scientists use—and between 400 million and 1.7 billion extra people can’t get enough water, some infectious diseases and allergenic pollens rise, and some amphibians go extinct. But the world’s food supply, especially in northern areas, could increase. That’s the likely outcome around 2020, according to the draft.
Add another 1.8 degrees and as many as 2 billion people could be without water and about 20 percent to 30 percent of the world’s species near extinction. Also, more people start dying because of malnutrition, disease, heat waves, floods and droughts—all caused by global warming. That would happen around 2050, depending on the level of greenhouse gases from the burning of fossil fuels.
At the extreme end of the projections, a 7- to 9-degree average temperature increase, the chart predicts: “Up to one-fifth of the world population affected by increased flood events ...
1.1 to 3.2 billion people with increased water scarcity ... major extinctions around the globe.”
Despite that dire outlook, several scientists involved in the process say they are optimistic that such a drastic temperature rise won’t happen because people will reduce carbon dioxide emissions that cause global warming.
“The worst stuff is not going to happen because we can’t be that stupid,” said Harvard University oceanographer James McCarthy, who was a top author of
a 2001 version of the panel report.
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A key element of the second major report on climate change being released Friday in Belgium is a chart that maps out the effects of global warming with every degree of temperature rise, most of them bad.
intergovernmental panel on climate change.