Wednesday, May 14, 2008

Climate change hitting Arctic faster, harder

A new study by WWF warns that climate change is having a greater and faster impact on the Arctic than previously thought.

The new report, called Arctic Climate Impact Science � An Update Since ACIA, represents the most wide-ranging reviews of arctic climate impact science since the Arctic Climate Impact Assessment (ACIA) was published in 2005.

The report shows that the melting of Arctic sea ice and the Greenland Ice Sheet is severely accelerated, prompting concerns that both may be close to their 'tipping point'; the point where, because of climate change, natural systems may experience sudden, rapid and perhaps irreversible change. "The magnitude of the physical and ecological changes in the Arctic creates an unprecedented challenge for governments, the corporate sector, community leaders and conservationists to create the conditions under which arctic natural systems have the best chance to adapt," said Dr Martin Sommerkorn, one of the report�s authors and Senior Climate Change Adviser at WWF International's Arctic Programme. According to last year's reports from the Intergovernmental Panel on Climate Change (IPCC), if the entire Greenland Ice Sheet were to melt, sea levels would rise 7.3m, making its status a global concern.

While it is currently impossible to accurately predict how much of the ice sheet will be melting, and over what time, the new report shows there has been a far greater loss of ice mass in the past few years than had been predicted by scientific models.

Likewise, the loss of summer Arctic sea ice has increased dramatically. In September 2007, the sea ice shrank to 39 per cent below its 1979-2000 average, the lowest since satellite monitoring began in 1979 and also the lowest for the entire 20th century based on monitoring from ships and aircraft.

Oxygen-poor oceans

Olive Heffernan Nature Reports Climate Change Published online: 8 May 2008

Oxygen, one of the essential elements for most of life on Earth, has become increasingly scarce across large expanses of the tropical oceans over the past half century. A new study, based on real-world observations, supports the predictions of climate models that the ocean will become oxygen-depleted as a consequence of global warming.

Lothar Stramma of the University of Kiel, Germany, and colleagues combined historical records with recent data taken from ships and buoys to reconstruct oxygen concentrations since 1960 at selected tropical ocean sites. They focused their study on waters of intermediate depth, where oxygen supply is weak and where changes would be expected to have larger consequences than in the oxygen-rich areas. Over the past 50 years, oxygen decreased by 0.09–0.34 micromoles per kilogram per year in the layer at 300–700 metres depth. Depletion was most severe in areas with the greatest increase in temperature.

Oxygen depletion is likely to worsen in the tropical oceans as temperatures rise, creating large 'underwater deserts'. The authors warn that this could decrease the survival of large mobile marine species such as tuna and could disrupt nutrient cycles in the tropical oceans, reducing the productivity of entire marine ecosystems.

World CO2 levels at record high, scientists warn

  • David Adam Monday May 12 2008

    Scientists at the Mauna Loa observatory in Hawaii say that CO2 levels in the atmosphere now stand at 387 parts per million (ppm), up almost 40% since the industrial revolution and the highest for at least the last 650,000 years.

    The figures, published by the US National Oceanic and Atmospheric Administration (NOAA) on its website, also confirm that carbon dioxide, the chief greenhouse gas, is accumulating in the atmosphere faster than expected. The annual mean growth rate for 2007 was 2.14ppm – the fourth year in the past six to see an annual rise greater than 2ppm. From 1970 to 2000, the concentration rose by about 1.5ppm each year, but since 2000 the annual rise has leapt to an average 2.1ppm.

    Scientists say the shift could indicate that the Earth is losing its natural ability to soak up billions of tons of carbon each year. Climate models assume that about half our future emissions will be re-absorbed by forests and oceans, but the new figures confirm this may be too optimistic. If more of our carbon pollution stays in the atmosphere, it means emissions will have to be cut by more than currently projected to prevent dangerous levels of global warming.

    Martin Parry, co-chair of the Intergovernmental Panel on Climate Change's working group on impacts, said: "Despite all the talk, the situation is getting worse. Levels of greenhouse gases continue to rise in the atmosphere and the rate of that rise is accelerating. We are already seeing the impacts of climate change and the scale of those impacts will also accelerate, until we decide to do something about it."

Florida wildfires ravage dozens of homes

ORLANDO, Fla. -- Damage is estimated at nearly $10 million for brush fires that swept through Brevard County, Florida damaging and destroying more than 160 homes.

One veteran firefighter said he was stunned after seeing some of the damage in Palm Bay where crews were continuing to put out hot spots and mopping up areas late Tuesday, WKMG-TV, Orlando, reported.

Statewide, more than 100 fires were reported burning Tuesday.

Myanmar death toll rises above 34,000

The death toll from Myanmar's devastating Cyclone Nargis has risen to 34,273, with 27,836 people missing, state radio said Tuesday. "According to to the latest information at 6pm today, 34,273 were killed, 1,403 were injured and 27,836 missing," it said in a report. The new official toll raises the number of those killed when the storm hit on May 3 from 31,938 dead and 29,770 missing ...