Wednesday, May 27, 2009

Permafrost meltdown may bog down global warming, for awhile

When permafrost thaws, microbes convert ancient organic matter in the frozen soil into climate-warming gases, like carbon dioxide and methane, potentially triggering a positive feedback loop that further melts the Arctic.

But the once-barren soil also spouts new—and larger—shrubs that can act as a carbon sink, and scientists have wondered what the net effect of permafrost thawing would be on atmospheric carbon balance. A new study published this week in Nature suggests that changing landscape can counterbalance the release of permafrost carbon—but only for a little while.

"The greening of the Arctic will not compensate for the huge amount of permafrost carbon that will be released," says lead author Ted Schuur, an ecosystem ecologist at the University of Florida in Gainesville.

Click here for the article in the latest edition of Scientific American.

Paint the world white to fight global warming

(stock photo of Palm Springs, California, where many rooftops are painted white to reflect more of the sun's radiant energy, keeping homes cooler, reducing the need for air conditioning).

As a weapon against global warming, it sounds so simple and low-tech that it could not possibly work. But the idea of using millions of buckets of whitewash to avert climate catastrophe has won the backing of one of the world’s most influential scientists.

Steven Chu, the Nobel prize-winning physicist appointed by President Obama as Energy Secretary, wants to paint the world white. A global initiative to change the colour of roofs, roads and pavements so that they reflect more sunlight and heat could play a big part in containing global warming, he said yesterday.

Speaking at the opening of the St James’s Palace Nobel Laureate Symposium, for which The Times is media partner, Professor Chu said that this approach could have a vast impact. By lightening paved surfaces and roofs to the colour of cement, it would be possible to cut carbon emissions by as much as taking all the world’s cars off the roads for 11 years, he said.

(I laughed when I first read this headline, but the more I looked into it the more sense it made. At the very least you'll cut down on your summer air conditioning bills and save some cash! To read the article in the UK's Times Online click here).

Sea's rise may prove greater in the northeast

In the debate over global warming, one thing is clear: as the planet gets warmer, sea levels will rise. But how much, where and how soon? Those questions are notoriously hard to answer.

Scientists at the National Center for Atmospheric Research, in Boulder, Colo., are now adding to the complexity with a new prediction. If the melting of Greenland’s ice sheets continues to accelerate, they say, sea levels will rise even more in the northeastern United States and Maritime Canada than in other areas around the world.

The researchers, Aixue Hu and Gerald A. Meehl, based their predictions on runoff data from Greenland and an analysis of ocean circulation patterns.

The complete New York Times article is here.

Sunday, May 24, 2009

MIT model predicts accelerating warming trends

Hotter and Hotter

If an unusually detailed computer simulation at the Massachusetts Institute of Technology has it right, global warming in this century is on track to be about twice as bad as predicted six years ago.

The MIT model is said to be the only one that incorporates among its variables possible changes in economic growth and other human activities and draws on peer-reviewed science on the climatic effects of atmospheric, oceanic and biological systems.

After running the model 400 times with slight variations in the inputs, the new predictions are for surface temperatures to warm by 6.3 to 13.3 degrees Fahrenheit. The prediction is for a 9.4-degree increase in the median temperature, more than double the 4.3 degrees predicted in a 2003 simulation.

Ronald Prinn, co-author of a paper in the Journal of Climate describing the results, said the higher numbers are due to several factors, including better economic modeling, new data showing a lower probability of low-emission scenarios in the future, and better accounting for the effects of past volcanoes and soot emissions.

The simulations also examined what is likely to happen under various policy scenarios. Without strong policies to curb greenhouse gas emissions, the changes in the computer model "stacked up so they caused more projected global warming," Prinn said in a statement. With drastic steps to curb emissions buildup, however, there was less change from the earlier projections.

-- Nils J. Bruzelius

Climate change confusion

A recent survey found that Americans lack consensus on global warming. Americans fall into six distinct groups regarding their climate change beliefs, attitudes and behaviors, according to a new report, Global Warming’s Six Americas, by researchers at Yale and George Mason universities.

The researchers, who surveyed 2,129 American adults, found that 18% of Americans are ‘Alarmed’ about climate change and believe it is happening, 33% are ‘Concerned’ and believe global warming is a serious problem but find it less important and urgent than the ‘Alarmed’ category. Another 19% of the people surveyed are ‘Cautious’ and somewhat convinced that global warming is happening but say they could change their minds.

That’s the good news.

The article in and a link to the complete 140 page pdf document is here.