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Soot causes twice as much global warming as previously thought Graphene device detects narcotics in a jiffy Prof Yash
Pal THIS UNIVERSE |
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Soot causes twice as much global warming as previously thought SOOT created by the incomplete burning of fossil fuels and organic matter is the second most important man-made substance behind global warming and reducing its emission into the atmosphere could buy valuable time in tackling climate change, a major study has found. New estimates of how much soot, or “black carbon” as it is known by scientists, is released into the atmosphere show that it causes about twice as much warming as previously believed. Cutting emissions could help to cool the planet, scientists said. Black carbon, which is released from diesel engines, coal-fired power stations and wood-burning stoves, has a warming effect of 1.1 Watts per square metre, which is about two-thirds the warming effect of carbon dioxide, the principle man-made greenhouse gas. The new study found that soot emissions globally are substantially larger than previously estimated. It found that black carbon is a significant cause of the rapid warming seen in northerly regions of America, Canada and northern Europe and Asia and its effects extend further South, inducing changes in rainfall patterns of the Asian monsoon. Reducing soot emissions with filters or more efficient forms of combustion could lower global temperatures over the coming couple of decades and would create a breathing space for the more difficult long-term task of reducing carbon dioxide emissions, scientists said. “There are exciting opportunities to cool climate by cutting soot emissions, but it is not straightforward. Reducing emissions from diesel engines and domestic wood and coal fires is a no-brainer, as there are tandem health and climate benefits,” said Professor Piers Forster of Leeds University, a co-author of the new report. “If we did everything we could to reduce these emissions, we could buy ourselves up to half a degree [Celsius] less warming, or a couple of decades of respite,” Professor Forster said. However, the incomplete combustion of fossil fuels and organic matter produces other substances, such as sulphate aerosols, that have an opposite effect by cutting out incoming sunlight and cooling the climate, the scientists warned. “Mitigation is a complex issue because soot is typically emitted with other particles and gases that probably cool the climate. For instance, organic matter in the atmosphere produced by open vegetation burning likely has a cooling effect. Therefore, the net effect of eliminating that source might not give us the desired cooling,” he said. “One great candidate is soot from diesel engines. It may also be possible to look at wood and coal burning in some kinds of industry and in small household burners. In these cases, soot makes up a large fraction of their emissions, so removing these sources would likely cool the climate,” Professor Forster added. The four-year study into soot, published in the Journal of Geophysical Research-Atmosphere, involved hundreds of scientists from around the world and was carried out under the auspices of the International Geosphere-Biosphere Programme based in Stockholm and the International Global Atmospheric Chemistry Project. “This study confirms and goes beyond other research that suggested black carbon has a strong warming effect on climate, just ahead of methane,” said David Fahey of the US National Oceanic and Atmospheric Administration. Unlike carbon dioxide, which lingers in the atmosphere for many decades, black carbon is soon washed out of the air and so cutting emissions will have an almost immediate effect on reducing global temperatures, said Tami Bond of the University of Illinois. “Mitigating black carbon is good for curbing short-term climate change, but to really solve the long-term climate problem, carbon dioxide emissions must also be reduced,” Dr Bond said. — The Independent
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Graphene device detects narcotics in a jiffy A new graphene-based device can pinpoint the presence of the tiniest amounts of performance enhancing drugs and steroids, rapidly and accurately, in athletes’ blood samples. Graphene, isolated for the first time by Manchester scientists in 2004, lies at the heart of the new device. It has the potential to revolutionise diverse applications from smartphones and ultra-fast broadband to drug delivery and computer chips. The breakthrough can see one molecule though a simple optical system and can analyse its components within minutes, or even detect infectious viruses. This involves plasmonics — the study of vibrations of electrons in different materials, the journal Nature Materials reports. Scientists from the Universities of Manchester and Aix-Marseille (France), who are behind the breakthrough, said the device could also be used at airports or sensitive locations to prevent concealment of explosives by terrorists or traffickers from smuggling drugs. — IANS
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THIS UNIVERSE How does science explain consciousness; and what are the scientific parameters that bring consciousness (chetna) in human beings? Please give some reference to read more about this aspect. I am convinced that while thinking about deep questions, one can transition into a state of mind that is as spiritual as one can get. I firmly believe that deep science is a spiritual discipline. While I am also asserting that while being spiritual one can also maintain reason and logic. What I have said above should not be too surprising to those who appreciate that science (and not so much technology tries to understand the mind of God or Nature that determines the being and properties of the universe. I am sorry I am not very good at recommending books to read on topics like this. Why do scientists say that light follows a straight path? And why do we consider its charge as positive? Perhaps we could call that path as a straight which the light takes in vacuum when moving without any disturbance! As far as your second question is concerned, giving a charge that is deficient in electrons as positive is only a convention. Readers can e-mail questions to Prof Yash Pal at palyash.pal@gmail.com
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Trends
LAS VEGAS: A low-cost space dwelling that inflates like a balloon in orbit will be tested aboard the International Space Station, opening the door for commercial leases of future free-flying outposts and deep-space astronaut habitats for NASA. The Bigelow Expandable Activity Module, nicknamed BEAM, will be the third orbital prototype developed and flown by privately owned Bigelow Aerospace. The Las Vegas-based company, founded in 1999 by Budget Suites of America hotel chain owner Robert Bigelow, currently operates two small unmanned experimental habitats called Genesis 1, launched in 2006, and Genesis 2, which followed a year later. Russia plans to send probe to moon in 2015 MOSCOW: Russia will resume a long-dormant quest to explore the moon by sending an unmanned probe there in 2015, the head of the space agency was quoted as saying. The craft, called Luna-Glob, or Moon-Globe, will be carried by the first rocket to blast off from a new facility that Russia is building in its far-eastern Amur region, Roskosmos director Vladimir Popovkin said, according to the Interfax news agency. "We will begin our exploration of the moon from there," he said of the new space centre that will decrease Russia's reliance of the Baikonur Cosmodrome in the ex-Soviet nation Kazakhstan, which it leases. Spanish research cuts force scientists to look abroad MADRID: Amanda Bolanos, a young Spanish scientist, knows she will not be coming home. “Exiled in Cambodia” read the banner the molecular biologist carried at a protest in Madrid against government cutbacks. Back on leave from Phnom Penh, the 30-year-old researcher plans to head for Latin America if her present contract in Cambodia is not renewed. She sees little chance of finding work in Spain. Bolanos and other scientists say sharp cuts in Spanish state spending on research and development, part of efforts to lower the national debt, leave them little choice but to go abroad. White House rejects Death Star petition WASHINGTON: The Obama Administration dashed the hopes of Star Wars geeks across the galaxy by rejecting an official petition calling for the US government to build a Death Star, the fictional planet-destroying space station featured in the Star Wars movies. “The Administration shares your desire for job creation and a strong national defence, but a Death Star isn't on the horizon,” said Paul Shawcross, head of the White House budget office’s science and space branch. — Reuters
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Steve Connor
