Arctic Ice May be Reaching a Threshold

Melting sea ice The phrase more commonly used in a report out today from the Environmental News Network is “tipping point”. A tipping point is, or course, a threshold where, once reached, things happen fast – no more slow, incremental change.

This summer’s thaw season in the Arctic saw a 20% increase in ice melt over the previous record melt in 2005.

Many scientists, such as NASA climate scientist James Hansen, fear that such accelerated melting could indicate a self-sustaining positive feedback loop causing polar ice in the north to completely disappear in summer before mid-century.

The ice melt has thus far been much faster than climate models have predicted. As such, whether Arctic ice is now at or beyond a tipping point is a matter of observational speculation and not scientific prediction. According to the Potsdam Institute for Climate Impact Research, Arctic ice has already passed the tipping point.

While the principal culprit for the rapid ice melt is most likely due to increased greenhouse gases in the atmosphere, Hansen says other factors may include soot from forest fires and industrial pollution from China and Russia. Hansen and other climate scientists thus urge continued and concentrated research in the region.

Arctic ice is floating, so sea levels do not rise when it melts (much like your drink doesn’t spill out of your glass when the ice cubes melt). However, the melting of the Arctic ice is a harbinger to what might happen to the Greenland ice sheet or in the Antarctic, where melting ice could raise sea levels anywhere from 7 meters to 57 meters.

Some assert that talk of “tipping points” and such is merely alarmist or politically motivated (see Jyle’s last post). But to ignore not only the warnings of scientists on the possible future consequences of climate change but also what is actually happening now, and to repeatedly call up the “alarmist” card in the face of it, is irresponsible at best and immoral at worst.

Sources and Further Reading
Environmental News Network:
Arctic Thaw May be at a Tipping Point
Arctic Summer Ice Thickness Halves to 1 Meter
Arctic Sea Route Opens

GlobalWarmingisReal:
The Scramble for the Arctic
Climate Science, Doomsday, and Funky Wisdom