Scientists Sound Alarm on Arctic Melting, "Abrupt" Climate Change at AGU Meeting

Scientists reporting their findings at this week's annual meeting of the American Geophysical Union in San Francisco have an important message for the world: Climate change is happening faster and more extreme than predicted.

NASA, for one, has released new satellite data showing that over two trillion tons of land ice in Greenland, Antarctica and Alaska have melted away dramatically since 2003. More than half of that ice loss has come from Greenland. In total, the melt has led to a global sea level rise of about one-fifth of an inch over the past five years.

The researchers used new satellite technology that measures changes in the mass of mountain glaciers and ice sheets. NASA geophysicist Scott Luthcke told the AP that the losses amount to enough water to fill the Chesapeake Bay 21 times.

"The ice tells us in a very real way how the climate is changing."

In another report, from the US National Snow and Ice Data Center (NSIDC), researchers revealed that temperatures in Arctic areas this autumn were 9 or 10 degrees Fahrenheit above average. The phenomenon, called "Arctic amplification," has been long predicted, but it wasn't expected to be seen for another 10 or 15 years, at least. From the researchers, via The Independent:

Julienne Stroeve, of the NSIDC, who led the study with her colleague Mark Serreze, said that autumn air temperatures this year and in recent years have been anomalously high. The Arctic Ocean warmed more than usual because heat from the sun was absorbed more easily by the dark areas of open water compared to the highly reflective surface of a frozen sea. "Autumn 2008 saw very strong surface temperature anomalies over the areas where the sea ice was lost," Dr Stroeve told The Independent...

A warning, via the AP:

"The pace of change is starting to outstrip our ability to keep up with it, in terms of our understanding of it," said Mark Serreze, senior scientist at the National Snow and Ice Data Center in Boulder, Colo., a co-author of the Arctic amplification study.

The US Geological Survey released its new report, Abrupt Climate Change, arguing that sea level rise and loss of sea ice are expected to far exceed the UN IPCC's "conservative" projections. The study states that "abrupt" changes in climate are likely to strike -- and indeed, they may already be happening.

The research defines "abrupt" as:

A large-scale change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades, and causes substantial disruptions in human and natural systems.

Peter Clark, a lead author on the report, said: "We now have data on glaciers moving faster, ice shelves collapsing and other climate trends emerging that allow us to improve the accuracy of some of our future projections." Perhaps most alarming -- and most surprising -- is the study's prediction of a permanent state of drought in the American Southwest. Via Science Daily:

"Our report finds that drying is likely to extend poleward into the American West, increasing the likelihood of severe and persistent drought there in the future," Clark said. "If the models are accurate, it appears this has already begun. The possibility that the Southwest may be entering a permanent drought state is not yet widely appreciated."

The USGS called the drought risk "among the greatest natural hazards facing the United States and the globe today.”

Among the report's other conclusions:

• Recent rapid changes at the edges of the Greenland and West Antarctic ice sheets show acceleration of flow and thinning, with the speed of some glaciers more than doubling. These "changes in ice dynamics can occur far more rapidly than previously suspected," the report said, and are not reflected in current climate models.
• Inclusion of these changes in models will cause sea level rises that "substantially exceed" levels now projected for the end of this century, which are about two feet – but data are still inadequate to specify an exact level of rise.
• The strength of "AMOC" ocean circulation patterns that help give Europe a much warmer climate than it would otherwise have may weaken by about 25-30 percent during this century due to greenhouse gas increases, but will probably not collapse altogether – although that possibility cannot be entirely excluded.
• Climate change will accelerate the emissions of methane, a potent greenhouse gas, from both hydrate sources and wetlands, and they quite likely will double within a century – but a dramatic, potentially catastrophic release is very unlikely.

Meanwhile, the year 2008 is on track to be one of the ten warmest years on record for the planet, reported the US National Oceanic and Atmospheric Administration. The World Meteorological Organization announced that the Arctic region this year hit the lowest level ever recorded.

What a week of sobering news on the rapid warming of the planet. The positive news is that Nobel Prize-winning physicist Steven Chu officially became Obama's nominee for energy secretary. The president-elect declared, in two sentences to remember:

His appointment should send a signal to all that my administration will value science. We will make decisions based on the facts, and we understand that facts demand bold action.

On the climate issue, the scientific facts keep rolling in. We now await the promise of bold action.

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