Scientist offers dire scenario at climate-change symposium in Minneapolis

Dire projections on global warming effects issued recently by the U.N.'s International Panel on Climate Change (IPCC) may prove to be as comparatively tranquil as "a Sunday school picnic" when the next scientific reports come out, a renowned earth scientist told an international symposium in Minneapolis.

The sober assessment Monday by David Schindler of the University of Alberta follows an IPCC report last week that said that even if world leaders realize their most ambitious plans to reduce greenhouse gas emissions, the earth would still warm by 6.3 degrees Fahrenheit by century's end.

Such levels, the report said, would see ocean levels rise by six feet by 2100 rather than the 1.5-foot rise predicted just two years ago, and the Arctic would experience a sea-ice free summer by 2030 rather than the end of the century.  In 2000 alone, the average rate of melting of glaciers in nine mountain ranges has doubled compared with the rate of the previous two decades.

Schindler said he's "not looking forward" to what he fears are even more grim reports on climate change by world scientists that will follow in the coming months. 
 
Another speaker at the University of Minnesota's Transatlantic Science Week agreed with Schindler that a cascading synergy of adverse climate-change effects could outrun snail-paced efforts to reduce of greenhouse gas emissions from burning fossil fuels in power plants and transportation sources mostly in developed and developing nations. 
 
Expanding population
David Tilman of the University of Minnesota told the symposium that expanding world population and wealth will fuel increased consumption and increase demand for agricultural production by 188 percent in just 50 years. That, Tilman said, would require nearly a doubling of available agricultural lands already under tillage in the United States and Europe, and much of that increase would be in tropical forests and savannas. 
 
Tilman said that gains in crop yields would not be nearly enough to offset the rapid rise in demand for food.

What does increased food consumption and melting glaciers have to do with climate change? 
 
Tilman explained that in the next 50 years, world population will expand from 6.7 billion to 9.5 billion people (there were 2.5 billion in 1950) and wealth will increase by 240 percent which, coupled with shifts to higher protein diets, will require massive conversions of land from forests and grasslands to agricultural production, something that's already occurring in the Amazon rain forests.

Such land-use changes, Tilman said, will result in the destruction of trees and grasses that store vast amounts of carbon and subsequent tillage that will release even more carbon to the atmosphere. In addition, he said, use of nitrogen fertilizers on cropland will cause still more release of greenhouse gas emissions.
 
"In 50 years," Tilman said, "agricultural production could release as much greenhouse gas as is currently released from fossil energy sources." 
 
Melting permafrost
Schindler's concern is focused on climate change in the arctic and vast regions of boreal forests in places like Canada.  Warming, he said, will further increase the melting of permafrost, which, he said, is woefully underestimated as a carbon storehouse, and it will bring pest invasions and subsequent destruction of forests that will lead to an increased incidence of forest fires. 
 
All of it and other effects that science is coming to better understand will reduce carbon storehouses and increase carbon releases.  Adding to the troubling scenario, Schindler said, is the rapidly expanding extraction of oil from tar sands across broad reaches of Canada that not only requires intense heat (burning of natural gas, primarily) but results in destruction of surface forests and their ecosystems. 
 
Much of Canada's oil production of tar sands is piped to Minnesota refineries. 
 
The world climate change agenda will take center stage in Copenhagen this December when the U.N.'s Framework Convention on Climate Change brings nations together for another attempt to come to grips with what a broad consensus of scientists warn is impending disaster due to rapid global warming.   
 
While it's yet to be seen is whether the world's primary emitters of greenhouse gasses (developed countries including the United States and those in Europe, and developing countries such as China, India and others in Asia) can advance agreements on ways to curb the ill effects of climate change. 
 
Little substantial change in greenhouse gas emissions has occurred since the Kyoto Protocol was adopted in Japan in 1997. 
 
The University of Minnesota symposium, an educational exchange between the United States, Canada and Norway, concludes Wednesday at the McNamara Alumni Center.

Ron Way can be reached at rway [at] minnpost [dot] com.