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Crop failures &
drought within our children’s lifetime Will the future for these children be even bleaker because of global warming? Perhaps, it will be so, scientists warn. — Reuters Prof Yash
Pal This universe Trends |
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Crop failures &
drought within our children’s lifetime Children today are likely to reach old age in a world that is 4C warmer, where the 10,000-year certainties of the global climate can no longer be relied on, and widespread crop failures, drought, flooding and mass migration of the dispossessed become a part of everyday life. This dire scenario could come as early as the 2060s — well within the lifetime of today’s young people. It could mark the point when, for the first time since the end of the Ice Age, human civilisation has to cope with a highly unstable and unpredictable global climate. A series of detailed scientific assessments of this possible “four-degree world”, published today, documents for the first time the immense problems posed if the average global temperature rises by 4C above pre-industrial levels — a possibility that many experts believe is increasingly likely. The international climate negotiations which resume this week in Cancun, Mexico, are aimed at keeping global temperatures within the “safe” limit of a 2C increase. But many scientists believe that, based on current trends, a rise of 3C or 4C is far more likely. The greatest concern is that a 4C increase in global average temperatures — a temperature difference as great as that between now and the last Ice Age — would create dramatic transformations in the world, leading to water shortages, the collapse of agriculture in semi-arid regions and triggering a catastrophic rise in sea levels in coastal areas. One of the studies, led by scientists from the Met Office’s Hadley Centre, predicts that, unless there is a concerted international agreement to curb dramatically the burning of fossil fuels such as coal, oil and gas, a 4C warmer world is virtually inevitable by the end of this century. This critical threshold could, however, be reached within just 50 or 60 years based on other factors, such as human interference with natural feedback cycles that accelerate global warming, and the sensitivity of the climate to man-made carbon-dioxide emissions. “Most emissions scenarios have a chance that take us past the four-degree point by the end of the 21st century, but it is down to the strength of the feedbacks and the sensitivity of the climate as to when this actually happens. It’s certainly not outrageous to say it could happen in the 2060s,” said Richard Betts, the lead author of the Hadley Centre study, published in the Philosophical Transactions of the Royal Society. Of equal concern to scientists is the speed of climate change. A second study in the series found that a global temperature rise of between 2C and 4C could be so rapid that it would coincide with the expected peak in global population, which is expected to reach nine billion by 2050 before it begins to fall. This would mean that the problems of water shortages and food production caused by climate change will occur at precisely the same time as the world is having to cope with feeding the greatest number of people in its history. A slower rate of climate change, on the other hand, will see the highest temperature increases occurring after the global population has peaked. Niel Bowerman of Oxford University, who led the study into the rate of climate change, said it highlighted the urgency of having emissions peak in coming years. “Our study shows we need to start cutting emissions soon to avoid potentially dangerous rates of warming within our lifetimes, and to avoid committing ourselves to potentially unfeasible rates of emissions reduction in a couple of decades time,” he added. —
The Independent |
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This universe Frankly, I am a little disturbed by the use of the word “spontaneous”. Nothing happens completely spontaneously without any disturbance, except as a statistical variation. When we expose a piece of sodium to air or moisture, it catches fire. This is truly not spontaneous on the part of that piece of sodium. It is only because the said exposure allows a chemical reaction that is exothermic. Sometimes a heap of straw containing lot of organic material heats up because of intense bacterial action and without loss of heat can rise to a temperature where a combustion might ensue. A dry forest might catch fire in a lot of wind because of a burning cigarette left by a workman, frictional heating through vigorous rubbing of dry wood on wood, sparks produced by stones falling on each other, or due to a lightening strike. None of these is a case of a spontaneous fire. There are fires and explosions in coalmines. I am no expert in this area, but I suspect that one of the reasons might be the following: The mining operation might produce a lot of coal dust hanging in the air. The slightest violent action like an axe striking a hard rock or a stone might produce some sparks that might be enough to ignite the coal dust hanging in the air. It is instructive to remember what happens when we light a fire, which is a phenomena in which a chemical reaction takes place producing enough energy to break the chemical potential barrier between oxygen and neighbouring atoms. When the chemical barrier is small, slightest perturbation allows us to break it. That happens in the case of the highly combustible substances. Perhaps there is also a probabilistic element involved in crossing over the barrier. This reminds me of an entirely different field where apparently a spontaneous reaction takes place. I am referring here to the radioactivity of elements like uranium where alpha particles are emitted without provocation, but randomly. These particles can be considered imprisoned within the potential well of the uranium nucleus and keep hitting the wall of this nucleus in an effort to get out. Due to quantum effects, they have a probability of leaking through the barrier. This probability defines the probability of alpha decay. Even though radioactive decay of uranium looks like a spontaneous effect, it depends on the momentum of the alpha particles in the nucleus and the probability of its leaking through.
Readers wanting to ask Prof Yash Pal a question can e-mail him at palyash.pal@gmail.com
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Trends WASHINGTON: Red dwarf stars are far more common than astronomers have believed-in fact, they may make up 80 percent of the star population, scientists said in a study on Wednesday that triples the number of stars in the universe. They analysed the light coming from galaxies known as elliptical galaxies and found they were chock full of these red dwarfs, which are small, cool stars. Secret military mini-shuttle headed back to Earth CAPE CANAVERAL, Florida: A miniature robotic space shuttle launched from Cape Canaveral in April has completed a nine-month classified mission for the military and will be headed for a landing as early as Friday, Air Force officials said. The vehicle, known as the Orbital Test Vehicle or X-37B, is expected to land at Vandenberg Air Force Base in California between Friday and Monday.
Huntington’s tests to aid drug search LONDON: Scientists have developed a new range of tests that allow them to track the progression of Huntington’s disease long before symptoms appear and should aid the development of drugs for the incurable inherited disease.
Finger length linked to prostate cancer risk LONDON: Men with long index fingers have a lower risk of prostate cancer, British scientists said on Wednesday, a finding that could be used to help select those who need regular screening for the disease. Researchers at Britain’s Warwick University and the Institute of Cancer Research (ICR) found that men whose index finger is longer than their ring finger were one-third less likely to develop the disease than men with the opposite pattern of finger lengths.said. —Reuters |
Children today are likely to reach old age in a world that is 4C warmer, where the 10,000-year certainties of the global climate can no longer be relied on, and widespread crop failures, drought, flooding and mass migration of the dispossessed become a part of everyday life.
This dire scenario could come as early as the 2060s — well within the lifetime of today’s young people.
