With much of the focus of atmospheric pollution on


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With much of the focus of atmospheric pollution on climate-changing gases such as carbon dioxide (CO2), there can be a tendency to downplay the risk posed by other pollutants. One such pollutant is sulfur dioxide, the chemical involved in acid rain, which is discussed in your chapter readings, and can also have a cooling effect on the climate. Other pollutants — among others — that are often overlooked as important to global climate change are methane, nitrous oxide, and black carbon (dark sooty particulates from burning of fossil fuels and biomass). Read: Read the article Accelerated Warming: The danger of clearing the air (Links to an external site.) by Anil Ananthaswamy in New Scientist (Note: You must be logged into ERNIE to use the Hunt Library). Consider the danger that these other pollutants may pose to the Earth’s climate, what their sources are, and if humans or nature are the drivers of these pollutants. Compare and contrast the effect of reducing these other “non-CO2” gases and aerosols, and postulate whether such reductions are feasible, either economically or socially. Post: State your opinion on which of these pollutants other than CO2 are of more concern to you and why, backing your opinion with data from your readings, or from other sources outside the class. If you use sources outside of class, be warned: Use your Critical Thinking Habits-of-Mind when comparing and contrasting different sources, and consider – really CONSIDER – where your sources are coming from. Do you feel they’re trustworthy? If so, why? If not, explain. link ATTACHMENT PREVIEW Download attachment article phys.pdf ADAM FERGUSON/VII MENTOR PROGRAM Smoke signal Carbon dioxide is not the only climate-altering pollutant. We ignore the others at our peril, says Anil Ananthaswamy 38 | NewScientist | 20 February 2010 I N JUNE 1783, lava and gases began pouring from the Laki fissure in Iceland in one of the biggest and most devastating eruptions in history. Poisonous gases and starvation killed a quarter of Iceland’s population. The effects of the eight-month-long eruption were felt further afield, too. In the rest of Europe, a scorching summer of strange fogs was followed by a series of devastating winters. In North America, the winter of 1784 was so cold the Mississippi froze at New Orleans. At the time, French naturalist Mourgue de Montredon suggested the eruption might be to blame, but two centuries passed before scientists started to work out how gas and dust from volcanoes affect climate. The main NASA IMAGE COURTESY JEFF SCHMALTZ, MODIS RAPID RESPONSE TEAM, GODDARD SPACE FLIGHT CENTER The brown haze that hangs over large parts of Asia is affecting the monsoon rains culprit is sulphur dioxide, which has a cooling effect. Laki pumped an estimated 120 million tonnes of the stuff into the atmosphere, cooling the northern hemisphere by as much as 0.3 °C over the next few years. Nowadays, we are pumping out amounts of sulphur dioxide each year comparable to Laki’s emissions. Human emissions rose rapidly over the 20th century, peaking at an estimated 70 million tonnes a year in the 1990s as developed countries cleaned up their act. Even such huge amounts, however, have not been enough to stop global warming: the cooling effect has been more than offset by the warming effect of carbon dioxide and other pollutants. We are only now beginning to understand the effects of some of those other pollutants. One of the major players is black carbon, produced by the burning of everything from dung to diesel. Some recent studies suggest it is one of the biggest causes of warming after CO2 in the short term, contributing to the rapid warming in the Arctic and the melting of Himalayan glaciers. These findings mean we face both a danger and an opportunity. When China and India reduce their sulphur dioxide emissions, the rate at which the planet is warming will rise dramatically. Satellite measurements show that China is already making headway, says Frank Raes o

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