Friday, January 16, 2009

Sea Level Rise Of One Meter Within 100 Years

From ScienceDaily (Jan. 11, 2009)

New research indicates that the ocean could rise in the next 100 years to a meter higher than the current sea level – which is three times higher than predictions from the UN's Intergovernmental Panel on Climate Change, IPCC.

The groundbreaking new results from an international collaboration between researchers from the Niels Bohr Institute at the University of Copenhagen, England and Finland are published in the scientific journal Climate Dynamics.

According to the UN's Intergovernmental Panel on Climate Change the global climate in the coming century will be 2-4 degrees warmer than today, but the ocean is much slower to warm up than the air and the large ice sheets on Greenland and Antarctica are also slower to melt. The great uncertainty in the calculation of the future rise in the sea level lies in the uncertainty over how quickly the ice sheets on land will melt and flow out to sea. The model predictions of the melting of the ice sheets are the basis for the Intergovernmental Panel on Climate Change's predictions for the rise in sea level are not capable of showing the rapid changes observed in recent years. The new research has therefore taken a different approach.

Looking at the direct correlation

"Instead of making calculations based on what one believes will happen with the melting of the ice sheets we have made calculations based on what has actually happened in the past. We have looked at the direct relationship between the global temperature and the sea level 2000 years into the past", explains Aslak Grinsted, who is a geophysicist at the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen.

With the help of annual growth rings of trees and analysis from ice core borings researchers have been able to calculate the temperature for the global climate 2000 years back in time. For around 300 years the sea level has been closely observed in several places around the world and in addition to that there is historical knowledge of the sea level of the past in different places in the world.

By linking the two sets of information together Aslak Grinsted could see the relationship between temperature and sea level. For example, in the Middle Ages around 12th century there was a warm period where the sea level was approximately 20 cm higher than today and in the 18th century there was the 'little ice age', where the sea level was approximately 25 cm lower than it is today.

A rise in sea level in the future as in the past

Assuming that the climate in the coming century will be three degrees warmer, the new model predictions indicate that the ocean will rise between 0,9 and 1,3 meters. To rise so much so quickly means that the ice sheets will melt much faster than previously believed. But it has already been observed that the ice sheets react quicker to increases in temperature than experts thought just a few years ago. And studies from the ice age show that ice sheets can melt quickly. When the ice age ended 11.700 years ago, the ice sheets melted so quickly that sea level rose 11 millimeters per year – equivalent to a meter in 100 years. In the current situation with global warming, Aslak Grinsted believes, that the sea level will rise with the same speed – that is to say a meter in the span of the next 100 years.

Monday, January 12, 2009

Rising Sea Levels could lead to Failed States

From: Sydney Morning Herald

Jonathan Pearlman and Ben Cubby

January 7, 2009

RISING sea levels could lead to failed states across the Pacific and require extra naval deployments to deal with increases in illegal migration and fishing, a Defence Force analysis says.

"Environmental stress" has increased the risk of conflicts over resources and food and may demand greater involvement by the military in stabilisation, reconstruction and disaster relief, the analysis, prepared by Defence's strategic policy division, says.

It warns there is a risk of a serious global conflict over the Arctic as melting icecaps allow easier access to undersea oil and gas deposits.

In Australia's northern waters, "climate change is expected to change the location of South-East Asian fishing grounds, causing an increase in illegal fishing," says a summary of the analysis. "This may raise demand for ADF patrols in these regions."

The warnings emerged as a leading NASA scientist, James Hansen, used an open letter to the US president-elect, Barack Obama, to single out Australia's coal exports as a significant cause of climate change.

"Australia exports coal and sets atmospheric carbon dioxide goals so large as to guarantee destruction of much of the life on the planet," Dr Hansen said.

The Defence analysis, titled Climate Change, The Environment, Resources And Conflict, was completed in November 2007 for the head of strategy, Michael Pezzullo, a deputy secretary who has since been appointed to oversee the preparation of the Defence White Paper.

"Environmental changes will reinforce existing concerns regarding land availability, economic development and control over resources," it says.

"Rising sea levels will affect states and islands with low-lying coastlines around the world … Food sources are also vulnerable to environmental changes."

A summary, obtained by the Herald under freedom of information laws, says: "Environmental stress, caused by both climate change and a range of other factors, will act as a threat multiplier in fragile states around the world, increasing the chances of state failure. This is likely to increase demands for the ADF to be deployed on additional stabilisation, post-conflict reconstruction and disaster relief operations in the future."

Defence refused to release the full 12-page analysis, saying its publication could damage Australia's defence capability and international relations.

The paper says climate change may lead to increases in refugees from Pacific islands, but says few are likely to be able to reach Australia.

"From a defence planning perspective, we don't know how quickly these changes will occur, exactly what their impact will be, or how states and societies will react," it says. "Nevertheless, climate change may affect security by increasing stress on fragile states, state and societal competition for resources, environmental threats to ADF infrastructure and increasing the frequency and severity of extreme weather events.

"Climate change is unlikely to increase the risk of major conflict, although there is one exception. The Arctic is melting, potentially making the extraction of undersea energy deposits commercially viable. … Conflict is a remote possibility if these disputes are not resolved peacefully."

The Prime Minister, Kevin Rudd, described climate change as a "fundamental" challenge last month when he released his national security statement.

Dr Hansen, head of NASA's Goddard Institute for Space Studies, said Australia was making "honest efforts" to tackle climate change but failing.

Carbon trading schemes such as that proposed by the Federal Government would slow the rate of greenhouse emissions too slowly, Dr Henson said.

"This approach is ineffectual and not commensurate with the climate threat," he said. "It could waste another decade, locking in disastrous consequences for our planet and humanity."

Australia is the world's largest exporter of black coal, shipping about 230 million tonnes a year to supply just over a quarter of world export demand, according to the Australian Coal Association.

It is the nation's biggest export earner, but when burned overseas Australian coal generates more than half a billion tonnes of greenhouse emissions each year, or more than all emissions generated within Australia.