NASA scientists propose reductions in black carbon in battle against global warming

NASA scientists propose reductions in black carbon in battle against global warming


In the battle against global warming, scientists say they some of the world’s largest emitters should adjust their focus from reducing emissions of carbon dioxide, to curbing the emissions of soot and methane.

NASA scientists, in a study published in Science, say that while carbon dioxide from fossil fuels like coal and oil remain a larger overall cause of global warming, reducing methane and soot may offer short-term solutions that could slow down the impacts of global warming.

The research, led by Drew Shindell of NASA’s Goddard Institute for Space Studies, finds that focusing on black carbon and methane measures could slow global mean warming 1 degree Fahrenheit by 2050, preventing between 700,000 and 4.7 million premature deaths each year.

While all regions of the world would benefit, countries in Asia and the Middle East would see the biggest health and agricultural gains from the emissions controls, said NASA officials.

The study, which was conducted under NASA, included an international team, which considered about 400 control measures. The new study focused on 14 measures with the greatest climate benefit. The study concludes that all 14 measures would curb the release of either black carbon or methane, pollutants that exacerbate climate change and damage human or plant health either directly or by leading to ozone formation. The new study builds upon research featured in an assessment report published last year by the United Nations Environment Program and the World Meteorological Organization.

The study also finds that hundreds of thousands of deaths would be prevented with such changes. Between 700,000 and 4.7 million premature deaths could be averted, say scientists. Black carbon, a product of burning fossil fuels or biomass such as wood or dung, is one of the leading causes of respiratory and cardiovascular diseases. The small particles also absorb radiation from the sun causing the atmosphere to warm and rainfall patterns to shift. In addition, they darken ice and snow, reducing their reflectivity and hastening global warming. Ways to cut back include building more efficient cookstoves, installing more filters on diesel vehicles, taking the worst polluting vehicles off the road and banning the practice of burning farmland, the study said.

Methane, a colorless and flammable substance that is a major constituent of natural gas, is both a potent greenhouse gas and an important precursor to ground-level ozone. Ozone, a key component of smog and also a greenhouse gas, damages crops and human health. Nations could update wastewater treatment plants, limit emissions from farm manure, drain rice paddies more often, capture gas that escapes from coal mines and oil and gas facilities and reduce leaks from long-distance pipelines.

The study comes as NASA has taken an increasingly vocal stance on the issue. NASA scientists have overseen as number of studies on global warming in recent months. A study released in late 2011 reaffirmed the impact of global warming, warning that the world could see an increase in temperature would likely lead to widespread destruction of ecological habitats, mainly by the introduction of invasive species drawn to warmer or cooler climates.

Meanwhile, researchers from NASA’s Jet Propulsion Laboratory and the California Institute of Technology in Pasadena, California, investigated how Earth’s plant life is likely to react over the next three centuries as Earth’s climate changes in response to rising levels of human-produced greenhouse gases.