30 May 2007Planet ArkMica Rosenberg
Atmospheric temperatures in the northernmost US state have risen by more than 3 degrees Fahrenheit (around 2 degrees Celsius) over the past five decades, Peter Larsen, a resource economist at the University of Alaska Anchorage, told a climate change conference in the Central American country of Belize.
Larsen led a study with a team of engineers to calculate how Alaska will cope with the highest temperatures it has experienced in the last 400 years, according to data gathered from ice cores.
"There is a rough magnitude of between US$5 and $10 billion of public infrastructure that's vulnerable to climate change just in Alaska," Larsen said on Monday night.
Permanently frozen ground, or permafrost, covers nearly two-thirds of the massive state but buildings, pipelines, roads and bridges crumble as it melts, he said at this week's meeting in Belize of Arctic peoples and tropical islanders who are suffering the worst effects of global warming.
An analysis of close to 20 types of public works in Alaska, from schools to municipal buildings, showed flooding and erosion will increase the burden on state finances.
Regular upkeep until 2080 would cost Alaska between US$32 and $56 billion without the extra stresses, said Larsen.
Some coastal areas like the Inupiat village of Shishmaref on a narrow Chukchi Sea barrier island are disappearing as sea levels rise, forcing a US$100 million relocation plan.
The temperature is rising in the Arctic regions at more than twice the rate of the rest of the world, according to the 2004 Arctic Climate Impact Assessment, a comprehensive study by scientists from eight nations.
Most scientists say it is very likely that human activities led by burning fossil fuels explain most of the global warming in the past 50 years.
Warming is accentuated in high-latitude regions like Alaska in part because of thinner atmospheres in the polar region, concentrating so-called greenhouse gases, and in part because of the nature of atmospheric currents, say studies.
