Global warming is threatening Earth’s ecosystems and efforts to harness those human activities contributing to it must begin immediately if the planet is to avoid the worst of the effects, said scientists at a three-day workshop on the world’s changing climate held this week in Homer. Climate change is now seen pole to pole, and while debate continues over what to do about it, there is no doubt that the phenomenon is real.
“That debate is pretty much over,” said Lara Hansen, chief climate scientist with the World Wildlife Fund, who has directed research on the biological effects of global changes since 1990.
Hansen spoke during the opening session of “Climate Camp: Alaska,” sponsored by the World Wildlife Fund and the Alaska Maritime National Wildlife Refuge, which concluded Wednesday at the Alaska Islands and Ocean Visitor Center.
The world’s carbon dioxide output is a major contributor to global warming, Hansen said. According to research data cited in a handout available at the workshop, half the world’s industrial carbon dioxide output already has dissolved into the oceans, decreasing their pH levels and outstripping their capacity to act as a buffer.
In other words, seawater is becoming increasingly acidic. By 2050 it will be more acidic than at any time in the last 25 million years. That will have detrimental effects on all manner of sea life, and on the ability of the oceans to absorb more carbon dioxide, further intensifying climate change.
Other impacts likely to affect human activities include shifting currents, which have been linked to climate change, rising sea levels, releases of methane hydrates in the marine and coastal environment — methane is 20 times as potent a greenhouse gas as carbon dioxide — and increasing sea temperatures, the handout said.
Rising water temperatures are threatening a range of species. Tropical coral reefs are dying because they’ve lost vital symbiotic algae. Canadian polar bears at Hudson Bay are underweight, which poses a threat to breeding, because earlier spring break-ups are cutting off as much as two weeks’ worth of hunting time, according to studies cited by the WWF.
In “Buying Time: A User’s Manual for Building Resistance and Resilience to Climate Change in Natural Systems,” Hansen, its lead author and editor, said that over the past century the average global temperature has risen 0.7 degrees Celsius.
Other studies cited on the WWF Web site say average temperatures have increased by 0.8 degrees Celsius since the advent of the Industrial Revolution (roughly 1780-1830), indicating the rate of increase is rising. Much of that increase in global average temperature is attributable to human activities like burning fossil fuels that release greenhouse gases.
In “Buying Time,” Hansen said the world could see carbon dioxide levels in the next 40 to 100 years that would roughly double pre-Industrial Revolution levels. Average temperatures could rise by as much as 5.8 degrees Celsius.
Scientists predict that an average increase of just 2 degrees Celsius would result in “dangerous and irreversible effects” worldwide, the Web site said, including a decline in agricultural output and increasing hunger, widespread water shortages, millions more put at risk of malaria and other diseases, a 60-percent loss of sea ice and coastal flooding that could cost nations hundreds of billions of dollars.
In 2002, sea ice coverage was the smallest since satellite records began, according to studies cited by Hansen. “Clearly most systems will be dramatically challenged and subsequently altered by changes of this magnitude,” Hansen said in “Buying Time.”
The WWF has proposed reducing greenhouse gas emissions to limit the extent of the temperature change to 2 degrees Celsius above pre-Industrial Revolution levels.
Hansen also said, however, that it appears the industrial past already has set in motion climate changes that are now unavoidable. Because the effects of greenhouse gases have “substantial lag time” within ecosystems, “we are locked into additional change from the concentrations … already in the atmosphere today,” she said.
Hansen noted that pollution controls in the United States have not kept pace with other areas of the globe. For instance, she said U.S. efforts to decrease the use of fuel in automobiles begun in the 1970s have not met their original targets. Fuel efficiency standards here have fallen well behind those of other industrialized nations, she said.
The problems are not insurmountable, Hansen said, but the time is short in which to initiate major worldwide conservation efforts to halt the increase of greenhouse gases in the atmosphere and avoid potentially catastrophic effects.
While nations must come together to effect large-scale change, even individuals can contribute to an overall solution by changing daily habits — for instance, by driving less and using energy-efficient products, she said.
The three-day workshop brought together environmental scientists, Bering Sea community leaders and others who seek to sustain and protect fish, wildlife and other resources.
In addition to Hansen, speakers included former Homer News writer Charles Wohlforth, author of “The Whale and the Supercomputer: On the Northern Front of Climate Change;” University of Alaska Fairbanks Professor Glenn Juday; Pacific Marine Environmental Lab Oceanographer Carol Ladd; and fisheries biologist Greg Ruggerone, a specialist on the survival of salmon in response to climate change.
Others scheduled to speak included Henry Oyoumick, Unalakleet watershed coordinator; Vernon Byrd, supervisory wildlife biologist with the Alaska Maritime National Wildlife Refuge; and Sue Mauger, stream ecologist with Cook Inlet Keeper, among others.
Also sponsoring the event were the National Science Foundation and the Center for Alaska Coastal Studies.
Hal Spence is a reporter for the Peninsula Clarion.
