Karin Zeitvogel Yahoo News 9 Jul 10;
WASHINGTON (AFP) – Targets set by policy makers to slow global warming are too soft to prevent more heatwaves and extreme temperatures in the United States within a few years, with grim consequences for human health and farming, a study warned this week.
Although the United States and more than 100 other countries agreed in Copenhagen last year to take action to reduce greenhouse gas emissions "so as to hold the increase in global temperature below two degrees Celsius," a study conducted by Stanford University scientists showed that might not be enough.
Stanford earth sciences professor Noel Diffenbaugh and former postdoc fellow Moetasim Ashfaq wrote in the study, published in Geophysical Research Letters, that "constraining global warming to two degrees C above pre-industrial conditions may not be sufficient to avoid dangerous climate change."
"In the next 30 years, we could see an increase in heatwaves like the one now occurring in the eastern United States or the kind that swept across Europe in 2003 that caused tens of thousands of fatalities," said Diffenbaugh, lead author of the study.
"Those kinds of severe heat events put enormous stress on major crops like corn, soybean, cotton and wine grapes, causing a significant reduction in yields," he said.
Diffenbaugh and Ashfaq used two dozen climate models to project what could happen in the United States if carbon dioxide emissions cause temperatures to rise 1.8 degrees Fahrenheit (one degree Celsius) between 2010 and 2039 -- a likely scenario, according to the UN's International Panel on Climate Change.
If that occurs, the mean global temperature in 30 years would be about 3.6 degrees Fahrenheit (two degrees Celsius) hotter than in the preindustrial era of the 1850s.
Many climate scientists and policy makers have set a two-degree Celsius increase as the upper threshold for temperature rise, saying beyond that the planet is likely to experience serious environmental damage.
But in their two-year study, Diffenbaugh and Ashfaq found that even if temperatures rise by less than two degrees Celsius above pre-industrial conditions, there is likely to be a spike in extreme seasonal temperatures and more and longer heatwaves.
The first impacts could be felt as early as during the next 10 years in the United States, the scientists said.
In the 2020s, an intense heatwave equal to the longest on record from 1951 to 1999 is likely to occur as many as five times a decade in parts of the United States -- even if global temperatures rise by only one degree Celsius, it said.
The 2030s could be even hotter, with more and longer heatwaves and a spike in extreme seasonal temperatures in the United States.
Along with rising temperatures, there would be a fall in precipitation and soil moisture could lead to drought-like conditions in parts of the United States, which would harm crop yields and could increase the number of wildfires, the study showed.
"I did not expect to see anything this large within the next three decades. This was definitely a surprise," said Diffenbaugh.
"It's up to the policymakers to decide the most appropriate action, but our results suggest that limiting global warming to two degrees Celsius does not guarantee that there won't be damaging impacts from climate change," he said.
Geophysical Research Letters is a peer-reviewed publication of the American Geophysical Union.
Climate Change Means More Heatwaves, Premature Deaths, Scientists Warn
Environment News Service 9 Jul 10;
WASHINGTON, DC, July 9, 2010 (ENS) - Climate change is a serious health hazard that the United States must prepare for, according to government and university scientists from across the country.
They advised Thursday that climate models show that global warming will increase air pollution and trigger more heat waves, floods and droughts, all of which will threaten human health.
"Climate change is a quintessential public health problem," said Michael McGeehin, director of the Division of Environmental Hazards and Health Effects at the Centers for Disease Control and Prevention, an agency of the federal government.
"Heat waves are a public health disaster. They kill, and they kill the most vulnerable members of our society," McGeehin warned. "The fact that climate change is going to increase the number and intensity of heat waves is something we need to prepare for."
McGeehin was one of several scientists who briefed reporters on a teleconference held by the nonprofit Union of Concerned Scientists.
Climate change models show that the kind of heat waves some parts of the country have been suffering through in recent weeks will occur more often and at closer intervals, and last longer, said David Easterling, a climatologist with the National Oceanic and Atmospheric Administration's National Climatic Data Center.
"The current spate of heat waves could be a harbinger of things to come," he said, pointing out that from January through May, this year has been the hottest on record for global average temperatures.
Climate change could even make regions of the Earth uninhabitable, according to Matthew Huber, professor of earth and atmospheric sciences at Purdue University. His research on the effects of heat stress, reported in the Proceedings of the National Academy of Sciences, calculated the highest temperature-humidity combination that humans can withstand.
Huber's findings show that if emissions from burning fossil fuels continue unabated, extremely high temperature and humidity levels could make much of the world essentially uninhabitable for human beings.
Over the long term, perhaps 200 or 300 years, the planet could experience an increase of average global temperatures of 10 to 15 degrees Fahrenheit.
Under that scenario, much of the world, including Australia, many Mediterranean countries, and parts of Africa, Brazil, China, India and the United States, would be so hot and humid that people would not be able to survive outside during heatwaves for more than a few hours.
"We can still decide to try to avoid that" by dramatically reducing the heat-trapping emissions that cause global warming, Huber said. "And from our calculations, it is something we should try to avoid."
Jonathan Patz, director of global environmental health at the University of Wisconsin, Madison, said that while climate change is a health threat, tackling it is a major public health opportunity.
He pointed out that the World Health Organization reports about one million people annually die prematurely from air pollution. He says that cutting global warming emissions also would reduce certain kinds of pollution, especially ground-level ozone.
"If we can reduce air pollution," Patz said, "we can save lives."
Patz's latest research found that cutting down on the number short car trips and reducing the number of miles driven by about 20 percent would save hundreds of lives, avoid hundreds of thousands of hospital admissions, and save billions of dollars in healthcare costs in the Midwest alone.
If drivers got out of their cars and either walked or rode a bicycle, Patz added, "we could probably double those health care cost savings."
Climate scientist Brenda Ekwurzel with the Union of Concerned Scientists, who moderated the press briefing, noted that addressing climate change is not all about saving polar bears and other faraway creatures and habitats.
"More and more, studies demonstrate that the health care impact and health care costs related to climate change," she said, "are directly related to us."
Read more!
Posts
visitors since Nov 07