MANMADE AEROSOLS MESSING UP THE MONSOON

This research reported in Science blames human activity for the negative change in the South Asian summer monsoon.

Abstract: 'Observations show that South Asia underwent a widespread summertime drying during the second half of the 20th century, but it is unclear whether this trend was due to natural variations or human activities. We used a series of climate-model experiments to investigate the South Asian monsoon response to natural and anthropogenic forcings. We find that the observed precipitation decrease can be attributed mainly to human-influenced aerosol emissions. The drying is a robust outcome of a slowdown of the tropical meridional overturning circulation, which compensates for the aerosol-induced energy imbalance between the northern and southern hemispheres. These results provide compelling evidence of the prominent role of aerosols in shaping regional climate change over South Asia.'

CLIMATE-CHANGE ROCKS EVEREST?

Scientists and observers are concerned that climate-change will ultimately turn even Everest, the world's highest peak, into a rock-climb. One climber said that he was able to scale it without crampons there was so much bare rock.

Full story here.>/a>

ELECTRIC CARS SLASH SOLAR-CELL PAYBACK TIME

BusinessGreen reports on figures released by British Gas which show that owners of electric cars who charge them from their own installations of solar cells slash the payback time for the installation to less than five years.

The figures are based on a 2.52kWp system at the home of actor and TV presenter Robert Llewellyn, who uses the panels to charge his Nissan Leaf.

WHY GLOBAL OVER-HEATING RISES UNEVENLY

These stories, at TG Daily and LiveScience report a study that explains why the inexorable rise in the average global temperature is proceeding in fits and starts. The deep oceans store excess heat temporarily, for as long as a decade.

Satellites show that the discrepancy between heat coming in and being reflected back into space is growing, so the excess heat must have been going somewhere. Now we know where.

SMALLEST NORTH POLE IN 8000 YEARS

A report in the Guardian newspaper shows that the extent of Arctic sea-ice is the smallest it has been since satellite observations began in 1972, and is almost certainly the smallest it has been for at least 8000 years.

If current trends continue, a largely ice-free Arctic in the summer months is likely within 30 years. That is up to 40 years earlier than anticipated in the last assessment report by the Intergovernmental Panel on Climate Change (IPCC).

CLIMATE-CHANGE THREATENS AGRICULTURAL PRODUCTION

Science magazine (published by the American Association for the Advancement of Science) has published a study of the global production of the four largest agricultural commodities over the last 30 years: maize, wheat, soybean and rice. Together they account for about 75% of the calories consumed by humans, directly or indirectly.

The study found that maize and wheat have been negatively affected by the rise in global temperatures; rice and soybean have not been affected. Maize production declined 3.8%, wheat 5.5%. The authors conclude that 'climate-changes are already exerting a considerable drag on yield growth', which translates into substantial rises in prices.

Full study here.

CUT THE SOOT TO SLOW WARMING

ScienceDaily reports that a new study of dust-like particles of soot in the air--now emerging as the second most important, but previously overlooked, factor in global warming--provides fresh evidence that reducing soot emissions from diesel engines and other sources could slow melting of sea ice in the Arctic faster and more economically than any other quick fix, a scientist reported in Denver, Colorado on August 31, 2011.

In a presentation at the 242nd National Meeting & Exposition of the American Chemical Society (ACS), Mark Z. Jacobson, Ph.D., cited concerns that continued melting of sea ice above the Arctic Circle will be a tipping-point for Earth's climate, a point of no return. That's because the ice, which reflects sunlight and heat back into space, would give way to darker water that absorbs heat and exacerbates warming. And there is no known way to make the sea refreeze in the short term.

Jacobson's calculations indicate that controlling soot could reduce warming above parts of the Arctic Circle by almost 3 degrees Fahrenheit within 15 years. That would virtually erase all of the warming that has occurred in the Arctic during the last 100 years.

'No other measure could have such an immediate effect,' said Jacobson, who is with Stanford University. 'Soot emissions are second only to carbon-dioxide in promoting global warming, but its effects have been underestimated in previous climate models. Consequently, soot's effect on climate change has not been adequately addressed in national and international global warming legislation. Soot emissions account for about 17 percent of global warming, more than greenhouse gases like methane. Soot's contribution, however, could be reduced by 90 percent in 5-10 years with aggressive national and international policies.'

SIMPLE CATALYST SPLITS WATER IN SUNLIGHT

Using computational science researchers at the universities of Kentucky and Louisville have found a simple new catalyst that splits water in sunlight, thus opening another carbon-free door to the hydrogen age.

Full story on ScienceDaily.