Oxygen therapy for oil spill

Oil spill, like the one off Mumbai coast in August, leaves crude oil on shores for years.

Scientists have devised a way to expedite biodegradation of oil. They collected soil samples from beaches in Prince William Sound in Alaska that saw one of the worst oil spills, 20 years ago. The samples were treated with phosphorus and nitrogen fertiliser in the presence of oxygen. Oil degraded five times faster.

This data was used to devise a treatment that involves applying the fertilizers to breakdown natural organic matter in sea sediment. This increases sediment porosity and allows oxygen in seawater to penetrate the affected zone.
Down To Earth Features

Origin of aerosols dictates cloud shape

How cloudy is it outside? The answers may depend on the level of atmospheric pollution in one’s region. Cloud-forming microscopic particles, called aerosols, absorb and reflect solar radiation. These particles have the ability to modify cloud formation and encourage or suppress precipitation.

They can be released from manmade sources like vehicles, industry, agriculture, and natural sources like sea salt, volcanic dust, sulphates from biogenic gases. Scientists are not fully aware of the role of aerosols in affecting climate because of lack of information on their distribution and characteristics.

Two scientific papers, published in the September 17 issue of Science, fill this gap. In the first study, more than 1,000 atmospheric aerosol profiles over the Pacific Ocean were analysed. Their results demonstrated that aerosol concentration is higher in areas of human perturbation as compared to pristine regions.

The study concluded that human intervention leads to aerosols with enhanced light scattering properties and radioactive effects, and increase in the number of particles available to form cloud droplets. In the second study, aerosol and cloud formation over the Amazon rainforests were studied during the wet season, when the air is at its most pristine.

It was found that the forest produced its own rain, that is, clouds and rain were formed by volatile gases emitted by plants. The data also showed that the number of cloud droplets above the Amazonian forests depended directly on the number of aerosols. This is in contrast to more polluted areas, where the number of cloud droplets depends on how quickly hot particles from burning fires or fossil fuels ascend into the atmosphere.
Smriti Sharma,
Down To Earth Features

Renewable energy: China’s role

China’s push for rapid economic development will dominate global energy markets and be the single biggest force in spurring higher oil prices and carbon emissions linked to climate change over the next quarter-century, the International Energy Agency reported recently. At the same time, however, China is poised to be the driving influence behind the development of renewable energy like wind and solar power, according to the agency’s annual energy outlook.

The agency, which is based in Paris and advises the industrialised nations, predicted that Chinese energy demand would soar 75 per cent by 2035, accounting for more than a third of the growth in global consumption. While China today accounts for 17 percent of world demand for energy, it should account for 22 per cent in 25 years, at the same time that India and other developing countries also expand their energy use. The growth in Chinese energy consumption has already been breathtaking, the report says. Over the last decade, China’s energy demand has doubled. While China used only half as much energy as the US in 2000, it actually surpassed the United States in 2009 as the world’s largest energy user.
Clifford Krauss,
New York Times News Service

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