Glacial Earthquakes? Uh-oh

Risk assessment for the impacts of climate change must be an active, ongoing, constantly-updated process. We're learning all the time, especially about feedback systems that affect the speed of change.

Here's an example of where the risk assessment for sea level rise is suddenly requiring a significant adjustment. The quickening pace of ice breaking off from the Greenland icecap means that our current estimates of sea level rise are both too low and too slow.

Thanks to Dave Roberts at Gristmill for pointing to this article in the Guardian (UK):

Melting ice cap triggering earthquakes

· Estimates of sea-level rise out of date, say scientists
· Religious leaders pray for planet at Greenland glacier

And from The Independent (UK) via Climate Ark, this ominous quote:

The accelerating thaw and the earthquakes are intimately connected, according to [Finnish scientist Veli Albert Kallio], as immense slabs of ice are sheared from the bed rock by melt water. Those blocks of ice, often more than 800m deep and 1500m long, contain immense rocks as well and move against geological faults with seismic consequences. The study of these ice quakes is still in its infancy, according to [American polar expert Robert Correll], but their occurence is in itself disturbing. "It is becoming a lot more volatile," said Mr Vallio. Predictions made by the Arctic Council, a working group of regional scientists, have been hopelessly overrun by the extent of the thaw. "Five years ago we made models predicting how much ice would melt and when," said Mr Kallio. "Five years later we are already at the levels predicted for 2040, in a year's time we'll be at 2050."

Glacial Melting - China

Climate Frog reported on the retreating glaciers on the south side of the Himalayas, a process that threatens the water supply to over a billion people. Now comes this report from the San Francisco Chronicle concerning glacial melting on the north side of the same mountainous region, this time affecting the water supply to a good part of China, home to another billion-plus citizens.

China has recognized the impact of this dwindling water supply as it has affected the high plateau grasslands, which had long supported the raising of livestock. With the shrinking of the pasture, many primitive ranchers have lost their livelihoods. Relocation - now common in China due to the damming of rivers and desertification - has become the solution for water-starved ranchers, too.

The Qinghai-Tibetan plateau is warming up faster than anywhere else in the world, Chinese scientists said last week. The region's average annual temperature is rising at a speed of 0.7 degrees Fahrenheit every 10 years, threatening to melt glaciers, dry up the 3,395-mile Yellow River and cause more droughts, sandstorms and desertification.

The plateau once contained 36,000 glaciers covering an area of 18,000 square miles, but in recent decades, the area of these glaciers has shrunk by 30 percent, say scientists from the Chinese Academy of Sciences.

The government has forcibly moved thousands of nomads into local towns, giving them free housing and 8,000 yuan (about $1,060) per year.

China, with its huge population and currently booming economy, will be as important as the U.S. in future calculations of global warming progress. Like the U.S., it must balance current economic prosperity and trends in that direction with the increasingly obvious impacts of its industrial development.

The nationwide economic boom has propelled China into overtaking the United States as the world's No. 1 source of greenhouse gas emissions, according to new data released in May. China's output of emissions is rising by an annual amount that far outstrips the cutbacks that wealthy nations are committed to make under the Kyoto Protocol.

"The Chinese government is gradually realizing that global warming is something that will deeply affect the Chinese people and their economic security," said Yang Ailun, climate program coordinator for Greenpeace in China.

In international climate negotiations, China's leaders have refused to consider binding limits on the country's emissions, arguing that limits should be imposed only on wealthy nations. Instead, China has adopted a goal of reducing the amount of energy expended per unit of wealth - a weaker yardstick that many environmentalists have criticized as insufficient.

India's Shrinking Glaciers

This quote from the New York Times science article (free subscription required) makes the case for reporting it in Climate Frog:

The thousands of glaciers studded across 1,500 miles of the Himalayas make up the savings account of South Asia’s water supply, feeding more than a dozen major rivers and sustaining a billion people downstream. Their apparent retreat threatens to bear heavily on everything from the region’s drinking water supply to agricultural production to disease and floods.

The glaciers of the Himalaya, which feed the rivers that flow through India, are among the least studied glaciers in the world. There is little history of their growth and shrinkage to refer to in evaluating trends, but since all glaciers in all parts of the world have been in major retreat for the past 20 years, it's safe to assume that the same is true in the Himalaya. The difference here is that a huge population- over a billion people - is dependent on the water that has historically been released through the dry season by the gradual melting of these accumulations of ice.

As the article says, the IPCC addresses the shrinking glacier problem in its recently released report.

In its report, the international panel predicted that as these glaciers melt, they would increase the likelihood of flooding over the next three decades and then, as they recede, dry up the rivers that they feed. “In the course of the century,” it warned darkly, “water supply stored in glaciers and snow cover are projected to decline, reducing water availability in regions supplied by meltwater from major mountain ranges, where more than one-sixth of the world population currently lives.”