(CNSNews.com) – The Obama administration Thursday welcomed a new report warning of the highest Arctic summer temperatures in two millennia, resulting in melting icecaps and a projected acceleration in sea-level rise. The findings are not necessarily in line with those from other studies.
“Arctic summer temperatures have been higher in the past few decades than at any time in the past 2,000 years,” stated the report by the Arctic Monitoring and Assessment Program (AMAP), attributing the finding to “evidence from lake sediments, tree rings and ice cores.”
It also found that 2005-2010 was “the warmest period ever recorded in the Arctic” and that “the Arctic Ocean is projected to become mostly ice-free in late summer within this century, perhaps within the next thirty to forty years.”
“The largest bodies of ice in the Arctic -- multi-year sea ice, mountain glaciers, ice caps and the Greenland Ice Sheet -- have all been declining faster since 2000 than they did in the previous decade, which may have a significant impact on the acceleration of sea-level rise in the future,” the report said.
“Global sea level is projected to rise by 0.9 to 1.6m (2.95 to 5.25 ft) by 2100, and Arctic ice loss will make a substantial contribution to this.”
The report was presented in Nuuk, Greenland, at a meeting of the Arctic Council – foreign ministers from eight Arctic countries – the first of its kind to be attended by an American secretary of state. AMAP is a working group of the Arctic Council.
The State Department said Secretary of State Hillary Clinton joined her Arctic Council counterparts Thursday “in welcoming the release of a major climate science report on the state of the frozen Arctic.”
“The United States urges forward looking cooperation among the Arctic countries to respond to the … findings and recommendations,” it said.
Addressing media after Thursday’s meeting, Clinton agreed with a reporter who said U.S. administrations had found it difficult to follow through on climate change commitments.
“You’re right that it’s been challenging in our political system to take the kinds of actions that we know are dictated by the science and by what we see in front of our eyes,” she said.
“Many of the indigenous people who are here at the Arctic Council meeting can give you very dramatic descriptions of how their land and the sea has changed in their lifetimes,” Clinton continued. “So there is no doubt, except among those who are into denying the facts before their eyes, that climate change is occurring, and it is contributed to by human actions at every level.”
Despite her tone and the striking assertions in the AMAP report, there are questions about some of the claims:
The AMAP report stated that “Arctic summer temperatures have been higher in the past few decades than at any time in the past 2,000 years.”
Other studies, however, have found that Arctic temperatures have fluctuated, and are now around the same level as they were in the mid-1930s.
Igor Polyakov of the International Arctic Research Center at the University of Alaska, Fairbanks tracked Arctic temperature records from the latter part of the 19th century until the current decade, and found that the 1930s marked the warmest time during that period.
Projected sea-level rise
During the 20th century, the sea level rose by an estimated 1.6-2.0mm a year -- a total of 16-20cm (6.3-7.8 inches) over the 100-year period.
Over the century to 2100, the AMAP report projects a global sea-level rise of between 90cm (2.9 feet) and 160cm (5.25 feet), and states that “Arctic ice loss will make a substantial contribution to this.”
But the Intergovernmental Panel on Climate Change (IPCC)’s most recent series of reports, released in 2007, projected that sea-level rise over the next 100 years would rise by between 18cm or 0.6 feet (the bottom of the range given in a best-case temperature-rise scenario) and 59cm or 1.9 feet (the top of the range in a worst-case scenario).
Even though the IPCC numbers did not take into account a possible acceleration of a thaw in polar regions, that is nonetheless a significantly smaller rise than the AMAP is projecting.
Furthermore, melting icecaps and glaciers will account for only some of the projected rise, the IPPC said, while the rest will be due to thermal expansion – the expansion in volume of water as a result of a rise in temperature.
Is sea-level rise accelerating?
According to the new AMAP report, Arctic ice has been melting faster since the year 2000 than during the previous decade, “which may have a significant impact on the acceleration of sea-level rise in the future.”
Other studies have found that, while there has been a small rise in sea-levels over the past century, the rate of the rise did not accelerate at all.
A 2010 German paper analyzing long-term tide gauge records over the period 1900-2006 found no “significant acceleration” in sea level rise.
A 2007 analysis of sea-level records over the period 1903-2003 found that the rate of sea-level rise was in fact higher in the first half of the 20th century than in the latter half.
And a 2011 analysis by U.S. experts of 57 tide gauges, each having data recorded over periods of between 60 and 156 years, found no acceleration in sea level rise, but on the contrary, a small deceleration.
In his Oscar-winning documentary An Inconvenient Truth, Al Gore declared that sea levels could rise by seven meters (22.9 feet) “in the near future” as a result of melting ice, a development which he said would displace millions of people.
After the film was used in British schools, it became the subject of a legal dispute.
In 2007, London High Court judge Michael Burton identified Gore’s sea-level prediction as one of nine significant errors in the film, calling it “distinctly alarmist” and an “Armageddon scenario.”