Greenland, Antarctica ice melt worsening, confirms Nasa

New satellite information shows that ice sheets in Greenland and western Antarctica continue to shrink faster than scientists thought and in some places are already in runaway melt mode.

British scientists for the first time calculated changes in the height of the vulnerable but massive ice sheets and found them especially worse at their edges. That's where warmer water eats away from below. In some parts of Antarctica, ice sheets have been losing 30 feet a year in thickness since 2003, according to a paper published online in the journal Nature.

Some of those areas are about a mile thick, so they've still got plenty of ice to burn through. But the drop in thickness is speeding up. In parts of Antarctica, the yearly rate of thinning from 2003 to 2007 is 50 per cent higher than it was from 1995 to 2003.

These new measurements, based on 50 million laser readings from a Nasa satellite, confirm what some of the more pessimistic scientists thought: The melting along the crucial edges of the two major ice sheets is accelerating and is in a selffeeding loop. The more the ice melts, the more water surrounds and eats away at the remaining ice.

"To some extent it's a runaway effect. The question is how far will it run?" said the study's lead author, Hamish Pritchard of the British Antarctic Survey. "It's more widespread than we previously thought."

The study doesn't answer the crucial question of how much this worsening melt will add to projections of sea level rise from manmade global warming.

Some scientists have previously estimated that steady melting of the two ice sheets will add about three feet, maybe more, to sea levels by the end of the century. But the ice sheets are so big it would probably take hundreds of years for them to completely disappear.

As scientists watch ice shelves retreat or just plain collapse, some thought the problem could slow or be temporary. The latest measurements eliminate "the most optimistic view," said Penn State University professor Richard Alley, who wasn't part of the study. The research found that 81 of the 111 Greenland glaciers surveyed are thinning at an accelerating, self-feeding pace. The key problem is not heat in the air, but the water near the ice sheets, Pritchard said.

Australia in list of countries with high carbon emissions; India figures in list

Australia’s economy is the worst-placed in the rich world to stay competitive when global efforts to curb climate change force a price on carbon-dioxide emissions, a report released on Monday found.

Australia ranked 15th in its ability to generate business in a low-carbon world, according to an analysis commissioned by London-based think tank E3G and Sydney’s The Climate Institute.

Only South Africa, India, Saudi Arabia and Indonesia had lower rankings. France, Japan, Britain, South Korea and Germany ranked highest for carbon competitiveness, because of their energy efficiency measures and their shift from reliance on coal for power generation.

In a preface to the report, economist and climate campaigner Lord Nicholas Stern said the global economic downturn provided an opportunity for countries like Australia to improve energy efficiency.

“Countries which don’t seize this opportunity will undermine their future competitiveness,” Mr. Stern said. Climate Institute head John Connor said that Australia had more work to do than any other nation to decouple economic growth from carbon emissions.

“We’re coming at the back of the pack in terms of how efficient our economies are and how we can be helping towards a global agreement,” he said. “This is something which puts our jobs and living standards at risk if we don’t get on with economy-wide measures to change our economy to cut carbon pollution and to increase our productivity.” Australians are the world’s worst carbon-dioxide polluters per capita, according to the British risk assessment company Maplecroft Ltd. The United States, Canada, the Netherlands and Saudi Arabia round out the top five emitters of greenhouse gases from fossil fuels in the per capita list Maplecroft released last week.

Australia has an average output of 20.5 tons of carbon dioxide per person per year, compared with 19.7 tons for the US, 4.5 tons for China and just 1.1 tons for India.