PACIFIC NORTHWEST - "It's not a scientific debate," Bill Pennell said of the human impact on global warming. "The fact we are doing something to climate systems is pretty well established."
Pennell studied climate change for 27 years as director of the Atmospheric Science and Global Change Division of Pacific Northwest National Laboratory in Richland. Last June, he became manager of the North American Research Strategy for Tropospheric Ozone (NARSTO).
"The challenge is in understanding what changes are likely to happen, when these changes are likely to become significant, and when and how we will have to adapt to them," he said.
So while there's more consensus than controversy in the scientific community, climate change is gaining steam as a "political debate, and for lots of good reasons," he said
Simply put, climate change in the 21st century "will be the most difficult environmental problem to face this planet," Pennell concluded.
Evidence mounting Scientists point to many harbingers of climate change, from the obvious, shrinking ice caps, to the subtle, changes in the migratory patterns of butterflies inspired by warmer temperatures.
But the supporting facts are piling up:
There's been a steady warming of the Earth's average surface temperature. Last year was the warmest since instrument recordings began in the late 1800s. During the past 30 years, Earth has warmed a tad more than 1 degree, making it the warmest it's been in 10,000 years.
Arctic sea ice has shrunk by 250 million acres since 1979 and the permafrost is thawing for what appears to be the first time in 120,000 years. Alaska's northern forests are declining while the tundra is seeing accelerated growth triggered by rising temperatures and pockets of carbon dioxide.
A temperature analysis of more than 600 boreholes throughout the Northern Hemisphere suggests the Earth's climate may be warming at a higher rate than tree-ring analysis and other methods have led scientists to believe.
Researchers believe that rising sea temperatures in the North Atlantic are primarily responsible for the worst drought in the Amazon in four decades.
Trees in Russia are adapting to a warmer and wetter environment, according to researchers from the United States and Europe. During the last 40 years, when forests in Russia have been subject to more dramatic shifts in climate than most regions, the typical shape of trees has undergone significant transformation, increasing leaves and needles while trunk size diminished.
In 2004, more than four dozen Northwest scientists said they were "very certain" the Pacific Northwest is warming. They said statistical analysis shows the region is growing warmer faster than the global average and is likely to warm three times as fast by the middle of the century.
Such evidence is spurring government action and a range of accords.
In October, Oregon Gov. Ted Kulongoski said a report by the region's leading scientists and economists answered the question, "Why does global warming matter?"
"The implications of global warming extend beyond our environment and will have an impact on the bottom line - our economic well-being," he said.
Kulongoski endorsed the report's call to action to ease the damage of global warming, which the scientists warned will reduce snowpacks and stream flows, overtax irrigation systems and increase the likelihood of forest disease and fire. He lent his support to new tailpipe emissions standards, now being designed to reduce carbon emissions throughout the state and regionally.
Working together In December, governors of seven Northeast states unveiled a pioneering bipartisan agreement to cut heat-trapping emissions from the region's power plants and create new investment in cleaner, more efficient energy technology. The pact sets tougher pollution limits and then rewards companies for outperforming them.
In February, nearly 100 evangelical Christian leaders announced their support for a global warming initiative calling for federal legislation that would require reductions in carbon dioxide emissions.
But while the realization is dawning that climate change deserves attention and action, the challenge could be magnified by what Bob Doppelt calls the poor climate literacy of the public.
As director of resource innovations at the University of Oregon, he helped coordinate the study on the economic impacts of climate change in Oregon. Focus groups held with business and civic leaders during the study showed few understand the issue of global warming.
"Many thought it had to do with the ozone hole, or with something far away that did not affect them," he said.
On the contrary, climate change will affect the world - and the Pacific Northwest more than some other areas, scientists believe.
Despite all that, Doppelt is hopeful.
"From my perspective, this issue is very solvable," he said. "Humans have solved complex problems many times in the past and we can do it again. We just need to get clear about the issue and get focused on the most efficient and effective actions."