New Findings on Global Warming

LIMITING METHANE, SOOT COULD CURB GLOBALWARMING

(ENS)- A recent study suggests that reducing methane emissionsand soot could significantly curb global warming. The GoddardInstitute for Space Studies, a division of the National Aeronauticsand Space Administration (NASA) says technologies are within reach toreduce methane in ways that are cheaper and faster than reducingcarbon dioxide. Global warming is caused by carbon dioxide(CO₂) emitted by the combustion of coal, oil and gas, andby other greenhouse gases including chlorofluorocarbons (CFCs),methane, tropospheric ozone and black carbon soot particles. Methaneis a naturally occurring gas, a product of a variety of biologicalprocesses. But the unnatural concentration of the gas fromhuman-induced factors is the problem. Methane can enter the atmosphereas a byproduct of the decomposition of garbage, such as fromlandfills, rice cultivation, industrial production and cattle herds.Meanwhile, a recent study published in the journal Nature indicatesthat soot may be the second biggest contributor to global warming,behind CO₂. “Soot, or black carbon, may be responsible for15 to 30 percent of global warming, yet it’s not even considered inany of the discussions about controlling climate change,” saysStanford Professor Mark Jacobson, an assistant professor of civil andenvironmental engineering and author of the study. Some 90 percent ofsoot comes from the consumption of fossil fuels, particularly dieselfuel, coal, jet fuel, natural gas and kerosene, as well as the burningof wood and other biomass when land is cleared,” said Jacobson.

BIOMASS BURNING ‘CANNOT GO ON’

(ENS) –Pollution may be seriously weakening the Earth’s watercycle, reducing rainfall and threatening fresh water supplies, says arecent study by researchers at the Scripps Institution ofOceanography. The scientists suggest that tiny particles of soot andother pollutants are having a far greater effect on the planet’shydrological cycle than previously realized. Tiny aerosols, primarilymade up of black carbon, can lead to a weaker hydrological cycle,which affects fresh water availability and quality on which human lifedepends, the authors argue. The study is based on results obtainedduring the International Indian Ocean Experiment (INDOEX), andappeared in the journal Science. “Through INDOEX we found thataerosols are cutting down sunlight going into the ocean,” said onelead scientist. “The energy for the hydrological cycle comes fromsunlight. As sunlight heats the ocean, water escapes into theatmosphere and falls out as rain. So as aerosols cut down sunlight bylarge amounts, they may be spinning down the hydrological cycle of theplanet.” Another scientist noted that aerosol particulates may besuppressing rain over polluted regions. Within clouds, aerosols canlimit the size of cloud droplets, stifling the development of thelarger droplets required for raindrops. If pollutants cut back on rainand snowfall, it could directly affect the replenishment of theworld’s major stores of freshwater, including lakes, groundwatersupplies, glaciers and high elevation snow pack. If humans continue todraw down these stores at a faster rate than they are replenished,access to fresh water could become the most crucial problem facingcivilization.