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| SCIENCE & TECHNOLOGY |
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Has
global warming stopped? No, it’s just on ‘pause’ Now, a
microchip that mimics human brain Prof Yash
Pal This
Universe |
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Has global warming stopped? No, it’s just on ‘pause’ HUGE amounts of heat — equivalent to the power of 150 billion electric kettles — are being continuously absorbed by the deep ocean, which could explain why global warming has “paused” over the past 10 to 15 years, scientists have concluded in a series of reports to explain why the Earth’s rate of warming has slowed down. Global average temperatures are higher now than they have ever been since modern records began. However, after a period of rapid temperature increases during the 1980s and 1990s, there has been a significant slow-down since the turn of the century, leading some sceptics to claim that global warming has stopped. A scientific assessment of the planet’s heat balance has found that the most likely explanation for the recent hiatus in global warming is the continual absorption of thermal energy by the huge “heat sink” of the deep ocean many hundreds of metres below the sea surface, according to scientists from the Met Office. Senior climate scientists said they had always expected periods when the rate of increase in temperatures would level off for a few years and emphasised that the last decade was still warmer than any previous decade, with 12 of the 14 hottest years on record occurring since 2000. Professor Rowan Sutton, a climate scientist at Reading University, said the temperatures have levelled off in the past, the latest example being in the 1940s and 1950s when sulphate pollutants from the post-war boom in industrial production may have acted as a shield against incoming solar radiation. “Some people call it a slowdown, some call it a hiatus, some people call it a pause. The global average surface temperature has not increased substantially over the last 10-15 years,” Professor Sutton said. “Climate scientists absolutely expect variations in the rate at which surface temperature will rise…but that is not to say we understand all the details of the last 10 to 15 years,” Professor Sutton said. The problem for the Met Office is to explain why the rate of increase in global temperatures has declined in recent years while concentrations of carbon dioxide in the atmosphere have continued to accelerate. Sceptics claim that this shows there is not a strong link between the two, whereas climate scientists insist that rising carbon dioxide concentrations are largely responsible for the rise in global temperatures. Professor Stephen Belcher, head of the Met Office Hadley Centre, said that a pause in the rate of increase in global temperatures lasting this long is unusual but not exceptional, with similar pauses of about 10 years expected on average twice every century. The most likely explanation for the current pause is that excess heat trapped by carbon dioxide in the atmosphere is being transferred from the atmosphere to the oceans where it is being transported down to deeper layers that cannot be monitored by satellites, Professor Belcher said. “It looks like the Earth is continuing to accumulate energy but it looks like it is being re-arranged and hidden from view,” he said. However, measurements from hundreds of ocean floats released over the last decade, which descend and drift to depths of up to 2,000 metres, show that huge amounts of heat from the sea surface is now being transferred to the deep ocean, with unknown consequences for the environment, the scientists said. “In summary, observations of ocean heat content and of sea-level rise suggest that the Earth system has continued to absorb heat energy over the past 15 years, and that this additional heat has been absorbed in the ocean,” says the Met Office report. The pause, however, is unlikely to change the predictions over the future course of global warming. Temperature increases expected by 2015 will only be delayed by a further five or 10 years, the scientists said. Average surface temperatures are still on course to increase by 2°C this century, with further rises expected by the end of the century if nothing is done to curb carbon dioxide emissions, they said. It is not possible to account for the recent lack of surface warming solely by looking at the difference between amount of heat being received from the Sun and the amount of thermal energy being lost from the planet — calculations show that extra heat continues to be absorbed by the Earth at a rate of 0.6 Watts per square metre, equivalent to about 300bn 1KW electric heaters or 150bn 2KW kettles distributed across the planet. “Observations of ocean heat content and of sea-level rise suggest that the additional heat from the continued rise in atmospheric carbon dioxide concentrations has been absorbed in the ocean and has not been manifest as a rise in surface temperature,” the Met Office says in one of its three reports into the global warming pause. “Radiated forcing by greenhouse gases has continued unabated; that heat is being held in the system but is not manifest as a rise in global mean surface temperature. Observations of ocean heat content and of sea-level rise suggest that this additional heat has been absorbed by the ocean,” it says. — The Independent
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Now, a microchip that mimics human brain SWISS scientists have developed a novel new microchip that works just like a human brain and exhibits cognitive abilities. No computer works as efficiently as the human brain — so much so that building an artificial brain is the goal of many scientists, researchers said. Researchers from the University of Zurich and ETH Zurich in Switzerland have now made a “breakthrough” in this direction by understanding how to configure so-called neuromorphic chips to imitate the brain’s information processing abilities in real time. They demonstrated this by building an artificial sensory processing system that exhibits cognitive abilities. Most approaches in neuroinformatics are limited to the development of neural network models on conventional computers or aim to simulate complex nerve networks on supercomputers. Few pursue the Zurich researchers’ approach to develop electronic circuits that are comparable to a real brain in terms of size, speed, and energy consumption, the researchers said. “Our goal is to emulate the properties of biological neurons and synapses directly on microchips,” said Professor Giacomo Indiveri. The major challenge was to configure networks made of artificial, i.e., neuromorphic, neurons in such a way that they can perform particular tasks, which the researchers have now succeeded in doing, the researchers said. They developed a neuromorphic system that can carry out complex sensorimotor tasks in real time. They demonstrate a task that requires a short-term memory and context-dependent decision-making — typical traits that are necessary for cognitive tests. The researchers combined neuromorphic neurons into networks that implemented neural processing modules equivalent to so-called “finite-state machines” — a mathematical concept to describe logical processes or computer programmes. Behaviour can be formulated as a “finite-state machine” and thus transferred to the neuromorphic hardware in an automated manner. The scientists thus demonstrate for the first time how a real-time hardware neural-processing system where the user dictates the behaviour can be constructed. — PTI
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This Universe I suppose human consciousness is anti-gravitational and wishes to expand like black energy but bound to earthly atmosphere by the black matter due to its gravitational effect. Please explain whether it is scientifically appropriate to draw such an inference. Perhaps it is more poetic and philosophic than scientific. Your statement can neither be proved nor disproved. Perhaps it is in a category which cannot be shown to be even wrong, though certainly not correct. Why don't you dream a bit more positively? After heavy rainfall I saw three to four times more stars at 3 am in the sky. I was astonished because these stars and their positions were completely different from the usual night sky. Please explain. One likely reason for your experience could be that the heavy rain had washed out the dust and pollution from the atmosphere and its transparency had greatly improved. Also at 3 am in the morning the background of city light might have been much less. Besides, you might have been looking at a denser portion of the Milky Way galaxy. I admire your interest in observing things of this sort. I want to become a scientist, so what stream should I take? Just wonder, dream, and follow your passion — to find out. This can be done through many streams. Just chose any which allows you to swim freely. Readers can e-mail questions to Prof Yash Pal at palyash.pal@gmail.com
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Trends LONDON: Drinking another person’s sweat may sound obnoxious, but a machine that takes sweat-laden clothes and turns the moisture into drinking water has been launched in Sweden. The device spins and heats the material to remove the sweat and then passes the vapour through a special membrane designed to only let water molecules get through, BBC reported. Since its launch, its creators said more than 1,000 people have “drunk other’s sweat” in Gothenburg city. The experts said the liquid was “cleaner” than local tap water. Return of bumblebee near Seattle stirs scientific buzz OLYMPIA, Washington: A North American bumblebee species that all but vanished from about half of its natural range has re-emerged in Washington state, delighting scientists who voiced optimism the insect might eventually make a recovery in the Pacific Northwest. Entomologists and bee enthusiasts in recent weeks have photographed several specimens of the long-absent western bumblebee — known to scientists as Bombus occidentalis — buzzing among flower blossoms in a suburban park north of Seattle. Snow falling around infant solar system WASHINGTON: Cosmic frost! Astronomers have discovered a snowy region in a far-off baby solar system, 175 light years away from the Earth. The snow line, located in the disc around the Sun-like star TW Hydrae, has been imaged in a far-off infant solar system for the very first time. The discovery promises to bring out more about the formation of planets and comets, the factors that decide their composition, and the history of the Solar System. — Agencies |
Steve
Connor
