Saturday, December 11, 2010

University of Kansas Researchers Track Antarctic Glacier

From: Kansas City InfoZine

A rugged and steady-going glacier is helping University of Kansas researchers more accurately predict future sea levels, which directly affect millions of people living near coasts worldwide.

Lawrence, KS - infoZine - “Sea level rise, even though we’re far from the ocean here in Kansas, is a global problem,” said Leigh Stearns, assistant professor of geology and co-principal investigator of the project. “Though the water will not be lapping at our doorsteps, climate change will affect storm tracks and precipitation amounts and patterns that we see.”
Studying glaciers is a good way to see how the climate is changing, Stearns added, because they often respond so sensitively to changes in temperature and precipitation. Stearns, along with a team of mountaineers and other scientists, traveled in November to East Antarctica to begin a three-year study of the large Byrd Glacier — a river of ice that slowly flows toward the Ross Sea. The team will use field observations, GPS units and satellites to track how evenly and quickly the ice moves, and to better predict how it may act in the future.
Much research has been done on the lively glaciers of Greenland and West Antarctica. Many of these have sped up substantially in the past decade and are now flowing at nearly six miles a year. For clues on why glaciers suddenly change their pace in this way, geologists must study more stable specimens like Byrd Glacier, Stearns said. This ice mass usually takes a year to crawl a half-mile but at times exhibits bursts of higher speed. Information on why and how the glacier accelerates will help scientists refine sea level rise predictions, which currently harbor large uncertainties with respect to changes in ice sheets. The work is funded by a $412,000 grant from the National Science Foundation.
“We don’t think that Byrd Glacier is responding to any large-scale climate changes right now, but it’s important for us to understand its dynamics in very good detail in case something does happen,” Stearns said. “A lot of the glaciers that we study, they change, and a bunch of scientists scurry over and try to understand what’s happening. But by that point, we’ve missed the baseline from what it used to be doing.”
Stearns, along with KU geography professor Cornelis van der Veen and others, placed 30 GPS units on the Byrd Glacier’s jagged surface. Each unit broadcasts its position, down to a fraction of an inch, every 15 seconds.
“Every 15 seconds we know the exact position of these 30 units attached to poles on the surface of the glacier,” Stearns said. “We can see how they’re moving throughout the season, whether the glacier flows at the same rate or moves in spurts.”
The fieldwork was not simple. No one else in recent memory has attempted to land on Byrd Glacier. Its surface is carved up by two-story-deep crevasses that appear in the ice as it moves. The team hopped from point to point in a helicopter, braving the chasms, the -22 degree cold and the biting winds of the Antarctic summer. The two experienced mountaineers came to ensure everyone’s safety.
“I always bring to the polar regions at least one explorer’s book from the 1900s — [Ernest] Shackleton or [Douglas] Mawson or [Robert Falcon] Scott,” Stearns said. “These guys did science when they didn’t know that they would make it home and survive. It’s fun to get a little lost in the adventure of what they went through versus how easy we have it.”
Stearns is a member of the Center for Remote Sensing of Ice Sheets, a multi-institutional effort established by the NSF in 2000. CReSIS, which is headquartered at KU, develops new technologies and computer models to predict how changing ice sheets relate to global sea levels.

Wednesday, December 08, 2010

Earth's gravest challenge: Not enough food to go round

By Greg Ansley ; New Zealand Herald 

 

As negotiators sat down this week for another hard round of bargaining at the climate change summit in Cancun, Mexico, new warnings emerged of potential catastrophe ahead.

Researchers reported in Science magazine that almost every part of the world's oceans have been damaged by human activity, magnified by a significant rise in water temperatures and predicted more would come.

Another study, by the ARC Centre of Excellence for Coral Reef Studies, warned of a potential mass extinction as the number of ocean dead zones - waters starved of oxygen - increase at an accelerating pace.

Yet another, released at Cancun by the Tyndall Centre for Climate Change Research, pointed to the increasing likelihood of frightening changes to rainfall, water supplies, weather systems, sea levels and crop harvests by the end of the century.

In Canberra, Professor Julian Cribb, one of Australia's most distinguished science writers, warns that the dangers facing humankind extend beyond the already-alarming projections of climate scientists, threatening the lives of hundreds of millions of people.

"The world has ignored the ominous constellation of factors that now make feeding humanity sustainably our most pressing task - even in times of economic and climatic crisis," Cribb writes in a disturbing new analysis of the state of the planet.

Cribb's book, The Coming Famine: The Global Food Crisis and What We Can Do to Avoid It, identifies a complex and interconnected confluence of factors driving the world towards a global emergency that experts predict will peak by the middle of this century.

"It is arriving even faster than climate change," he writes.

Cribb and the battery of experts he cites say there remains time to forestall catastrophe, identifying a range of measures that could be put in place, but warn that the world has barely begun to understand the ramifications of what it now faces.

The main drivers of the looming crisis include population growth that will reach 9.2 billion by 2050 (most in the poorer nations), rising demand for protein foods such as meat, milk, fish and eggs, and a global food requirement by 2050 that will be up to double today's, outstripping growth in food output.

Fuelling this will be growing shortages of water and productive land - 25 per cent of land is already so damaged it can barely yield food - declining nutrients, high energy costs, over-fishing, decimation of coral reefs and ocean food chains, declining agricultural research, climate change, and economics, politics and trade policies that distort world markets.

War and its appalling flow-ons could also be a consequence - in the past decade conflict has been triggered by land disputes and corrupt land distribution, environmental degradation, famine and water resources.

More, and possibly worse, could be in store. British defence analysts have predicted that rising populations, declining resources and climate change will increase the risk of food price spikes and shortages, water scarcities in volatile regions, mass displacement cause by climate or resource scarcities, a possible collapse in fish stocks, and greater risk of civil wars, intercommunal violence, insurgency, pervasive criminality and widespread disorder.

The Intergovernmental Panel on Climate Change also said flooding of coastal communities could trigger an even more alarming prospect: "Armed conflict between nations over resources, such as the Nile and its tributaries, is likely and nuclear war is possible."

The strain on global water supplies is enormous and growing, under pressure from irrigation to meet rising food demand, the explosion of cities, demand for higher-quality diets as economies grow, extraction exceeding natural rates of recharge, ignorance over the real state of water reserves, pollution, salinity and acidity, desertification, and poor management, farming practices and infrastructure.

The International Water Management Institute predicts that by 2050, more than two billion people will face severe water scarcity, and a further five billion moderate shortages.

Land is also running short. Global agricultural financier Rabobank estimates that the area of food production has shrunk from 0.45ha a person in the 1960s to 0.23ha, and will fall further, to about 0.18ha, by 2050.

New land is increasingly scarce, while productive land is being lost through accelerating soil degradation faster than new areas can be opened up - and much of the new land that is turned to farming has poor soil, requiring massive inputs of fertiliser and energy or drainage.

More land will be lost to rising sea levels, and at greater risk from salinisation, more and fiercer storms, worse flooding by rivers held back by rising seas: in the vital Bay of Bengal alone, a 40cm sea-level rise would inundate 11 per cent of its coastal lands, ripe out one-sixth of Bangladesh's rice harvest and displace 13 million people.

Researchers further warn that oceans - and the life they support - are under growing threat from acidity that Britain's Royal Society says is now irreversible in our lifetimes. It will require tens of thousands of years to restore ocean chemistry to pre-industrial revolution conditions.

While Cribb says co-operation, sharing of knowledge, and the subordination of national pride, greed and fear could stave off the worst, failure to work to guarantee the global food supply would mean catastrophe: "If through our neglect or abuse of resources it fails, each of us will bear the consequences."

Straight from the horse's mouth

Digging into a mountain of caviar, sea urchin roe, succulent Kyoto beef, rare conger eels, truffles and fine champagne, the leaders of the world's richest and most powerful countries shook their heads over soaring grocery prices in the developed world and spreading hunger in Africa, India, and Asia.

Over an 18-course banquet prepared for them by 60 chefs, the eight global potentates declared: "We are deeply concerned that the steep rise in global food prices coupled with availability problems in a number of developing countries is threatening global food security. The negative impacts of this recent trend could push millions more back into poverty." (Statement issued after the July 2008 meeting of the Group of Eight nations in Hokkaido, Japan.)

- From Julian Cribb's book The Coming Famine: The Global Food Crisis and What We Can Do To Avoid It

Earth's gravest challenge: Not enough food to go round

By Greg Ansley ; New Zealand Herald 

 

As negotiators sat down this week for another hard round of bargaining at the climate change summit in Cancun, Mexico, new warnings emerged of potential catastrophe ahead.

Researchers reported in Science magazine that almost every part of the world's oceans have been damaged by human activity, magnified by a significant rise in water temperatures and predicted more would come.

Another study, by the ARC Centre of Excellence for Coral Reef Studies, warned of a potential mass extinction as the number of ocean dead zones - waters starved of oxygen - increase at an accelerating pace.

Yet another, released at Cancun by the Tyndall Centre for Climate Change Research, pointed to the increasing likelihood of frightening changes to rainfall, water supplies, weather systems, sea levels and crop harvests by the end of the century.

In Canberra, Professor Julian Cribb, one of Australia's most distinguished science writers, warns that the dangers facing humankind extend beyond the already-alarming projections of climate scientists, threatening the lives of hundreds of millions of people.

"The world has ignored the ominous constellation of factors that now make feeding humanity sustainably our most pressing task - even in times of economic and climatic crisis," Cribb writes in a disturbing new analysis of the state of the planet.

Cribb's book, The Coming Famine: The Global Food Crisis and What We Can Do to Avoid It, identifies a complex and interconnected confluence of factors driving the world towards a global emergency that experts predict will peak by the middle of this century.

"It is arriving even faster than climate change," he writes.

Cribb and the battery of experts he cites say there remains time to forestall catastrophe, identifying a range of measures that could be put in place, but warn that the world has barely begun to understand the ramifications of what it now faces.

The main drivers of the looming crisis include population growth that will reach 9.2 billion by 2050 (most in the poorer nations), rising demand for protein foods such as meat, milk, fish and eggs, and a global food requirement by 2050 that will be up to double today's, outstripping growth in food output.

Fuelling this will be growing shortages of water and productive land - 25 per cent of land is already so damaged it can barely yield food - declining nutrients, high energy costs, over-fishing, decimation of coral reefs and ocean food chains, declining agricultural research, climate change, and economics, politics and trade policies that distort world markets.

War and its appalling flow-ons could also be a consequence - in the past decade conflict has been triggered by land disputes and corrupt land distribution, environmental degradation, famine and water resources.

More, and possibly worse, could be in store. British defence analysts have predicted that rising populations, declining resources and climate change will increase the risk of food price spikes and shortages, water scarcities in volatile regions, mass displacement cause by climate or resource scarcities, a possible collapse in fish stocks, and greater risk of civil wars, intercommunal violence, insurgency, pervasive criminality and widespread disorder.

The Intergovernmental Panel on Climate Change also said flooding of coastal communities could trigger an even more alarming prospect: "Armed conflict between nations over resources, such as the Nile and its tributaries, is likely and nuclear war is possible."

The strain on global water supplies is enormous and growing, under pressure from irrigation to meet rising food demand, the explosion of cities, demand for higher-quality diets as economies grow, extraction exceeding natural rates of recharge, ignorance over the real state of water reserves, pollution, salinity and acidity, desertification, and poor management, farming practices and infrastructure.

The International Water Management Institute predicts that by 2050, more than two billion people will face severe water scarcity, and a further five billion moderate shortages.

Land is also running short. Global agricultural financier Rabobank estimates that the area of food production has shrunk from 0.45ha a person in the 1960s to 0.23ha, and will fall further, to about 0.18ha, by 2050.

New land is increasingly scarce, while productive land is being lost through accelerating soil degradation faster than new areas can be opened up - and much of the new land that is turned to farming has poor soil, requiring massive inputs of fertiliser and energy or drainage.

More land will be lost to rising sea levels, and at greater risk from salinisation, more and fiercer storms, worse flooding by rivers held back by rising seas: in the vital Bay of Bengal alone, a 40cm sea-level rise would inundate 11 per cent of its coastal lands, ripe out one-sixth of Bangladesh's rice harvest and displace 13 million people.

Researchers further warn that oceans - and the life they support - are under growing threat from acidity that Britain's Royal Society says is now irreversible in our lifetimes. It will require tens of thousands of years to restore ocean chemistry to pre-industrial revolution conditions.

While Cribb says co-operation, sharing of knowledge, and the subordination of national pride, greed and fear could stave off the worst, failure to work to guarantee the global food supply would mean catastrophe: "If through our neglect or abuse of resources it fails, each of us will bear the consequences."

Straight from the horse's mouth

Digging into a mountain of caviar, sea urchin roe, succulent Kyoto beef, rare conger eels, truffles and fine champagne, the leaders of the world's richest and most powerful countries shook their heads over soaring grocery prices in the developed world and spreading hunger in Africa, India, and Asia.

Over an 18-course banquet prepared for them by 60 chefs, the eight global potentates declared: "We are deeply concerned that the steep rise in global food prices coupled with availability problems in a number of developing countries is threatening global food security. The negative impacts of this recent trend could push millions more back into poverty." (Statement issued after the July 2008 meeting of the Group of Eight nations in Hokkaido, Japan.)

- From Julian Cribb's book The Coming Famine: The Global Food Crisis and What We Can Do To Avoid It

Sunday, December 05, 2010

Satellites Reveal Differences In Sea Level Rises

by Phillip F. Schewe from Inside Science News Service

WASHINGTON (ISNS) - Glaciers are retreating and parts of the ice sheets on Greenland and Antarctica are melting into the ocean. This must result in a rise in sea level, but by how much? 

New maps show rise in sea level greater in some places than others
Relative sea-level change rates in millimeters per year.
Credit: GRACE

A new measurement of the gravity everywhere around the globe with a pair of orbiting satellites provides the first ever map detailing the rises across different parts of the globe.

According to the new results, the annual world average sea level rise is about 1 millimeter, or about 0.04 of an inch.  In some areas, such as the Pacific Ocean near the equator and the waters offshore from India and north of the Amazon River, the rise is larger.

In some areas, such as the east coast of the United States, the sea level has actually dropped a bit over the past decade.

The surface of the sea is a constantly shifting fabric. To achieve a truer sense of how much the sea is changing in any one place, scientists measure the strength of gravity in that place. Measuring gravity over a patch of ocean or dry land provides an estimate of how much mass lies in that region. The measured mass depends on the presence of such things as mountains, glaciers, mineral deposits, and oceans. 
If the gravity measurement for a place is changing, this could mean that the place is losing mass because of a retreating glacier or gaining mass if, as in the ocean surrounding Antarctica, new melt water is streaming in.
The Gravity Recovery and Climate Experiment, or GRACE for short, consists of a pair of satellites moving in an orbit that takes them over the South and North Poles. The two craft, nicknamed Tom and Jerry after the television cartoon characters, send constant signals to each other to determine their relative spacing to about 10 microns -- one-tenth the width of a human hair -- over a distance of 130 miles. If the first craft flies above a slightly more weighty area of the Earths' surface -- like a mountain range -- it will be tugged a bit out of place, an effect picked up by a change in the relative spacing of the craft.
In these way monthly gravity maps of pieces of land or ocean about 180 miles wide can be made with high precision. The new report for the years of 2003-09 looks at how much mass has been lost from land areas and how much mass has been gained by ocean areas. 
One of the authors of the report, Riccardo Riva from the Delft University of Technology in the Netherlands, said that average annual rise in sea level rise due to meltwater entering the ocean is about 1 millimeter, but that an additional rise will come from that fact that as the average temperature rises so does the ocean temperature, which in turn causes the volume of the ocean to increase. 
"The most important result of the new report is the measurement of the sea level changes for specific regions of the Earth that are based on direct and global measurements of mass change," Riva said.
Mark Tamisiea, who works at the National Oceanography Centre in Southampton, England, and was not involved in the GRACE work, believes the new report represents good research.
"As coastal sea level changes impact society, it is important for us to understand as much about the local differences from the global average as possible," Tamisiea said. "These results are one piece in that puzzle."
"GRACE is definitely the 'real deal' when it comes from measuring climate change from space," said Joshua Willis, an ocean expert at the Jet Propulsion Laboratory in Pasadena, Calif. "This work by Dr. Riva and company reminds us that the world's oceans don't behave like a giant bathtub. As the ice melts and the water finds its way back to the ocean, the resulting sea level rise won't be the same all over the world."
"These effects are still small in today's rising ocean, but as we look out over the next century, the patterns of sea level change due to melting ice will be magnified many times over as the ice sheets thin and melt," Willis said.
Looking at the actual map of sea level rises presents an ironic twist. Offshore the areas where melting ice is most rapidly falling into the ocean -- such as Greenland and Antarctica -- the sea level appears to be falling.
"The main reason for this is the rebound of the solid Earth," explained Riva. "Less ice causes the continents go up, and therefore sea level drops. Meltwater distributes around quite quickly, in most cases, so there is no accumulation due to that."
The new GRACE results appear in the journal Geophysical Research Letters.