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Double
food output to stop world from starving Prof Yash
Pal This Universe Trends Scientists glean lessons from stalled AIDS vaccine |
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Double food output to stop
world from starving A second “green revolution” is needed in agriculture to feed the extra 3 billion people who will be added to the existing population of 6 billion by 2050. The experts, drawn from the Royal Society, Britain’s national academy of scientists, believe that a variety of short-term and longer-term measures will have to be adopted urgently if agricultural production is to meet the demands made by the growth in human numbers. They cite the original green revolution of the 1960s when new crop varieties, greater use of agro-chemicals, and a change in farming practices led to a dramatic increase in food production: it leapt from 1.84 billion tonnes in 1961 to 4.38 billion tonnes in 2007. But scientists accept that this increase came at great environmental cost, and the Royal Society report warns that a second green revolution has to be based on a sustainable increase in global food production without a significant expansion in the area of land turned over to farming. “There is insufficient water to support an increase in the cultivated areas, and the environmental consequences of increasing cultivated areas are undesirable. Additional production will have to take place without further damage to [the environment],” the Royal Society report says. The area of land available to sustain each human being is “dangerously declining” because of soil degradation, the report says. Professor Sir David Baulcombe of Cambridge University, who led the study, said that the Government must be prepared to pay £2bn over a period of 10 years to fund research into ways of boosting food production around the world. “We need to take action now to stave off food shortages. If we wait even five to 10 years, it may be too late. Biological science has progressed in leaps and bounds in the last decade and UK scientists have been at the head of the pack when it comes to topics related to food crops,” Professor Baulcombe said. “In the UK, we have the potential to come up with viable scientific solutions for feeding a growing population, and we have a responsibility to realise this potential. There’s a very clear need for policy action and publicly-funded science to make sure this happens,” he said. The Royal Society report says that a range of measures, from new ways of managing crops —such as changes to the way they are irrigated — to the introduction of GM varieties that are drought-resistant or salt-tolerant, will all have to be called upon to boost food production. “There is no panacea for ensuring global food security. Science-based approaches introduced alongside social science and economic innovations are essential if we’re to have a decent chance of feeding the world’s population in 40 years’ time,” Professor Baulcombe said. “Technologies that work on a farm in the UK may have little impact for harvests in Africa,” he said. —By arrangement with
The Independent
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This Universe Does energy get destroyed when we try to push a heavy rock with all our might and fail to move it? Energy is definitely used up. Your force may not move the rock through a measurable distance but other changes do occur. Smallest movement of the rock might account for a lot of energy expended. But lot of energy also goes into pumping up your muscles, in pumping blood, in the tension in your arms and legs and in heating up your body. As your body heats up the energy is lost to the atmosphere through radiation. You will begin to perspire and energy is used up in evaporating that perspiration to keep you cool. If you have been working hard to push the rock you might have scratched your palms. That would also use some of your energy. You never destroy energy; you only transform it. Why do most heavenly bodies revolve in the
anti-clockwise direction in the universe? It is difficult to define clockwise or anti-clockwise in a three dimensional universe. Often it would depend on the direction from which you are looking. When we look at a diagram showing the directions in which the earth and the other planets move around the sun, we usually find that this direction is anti-clockwise. But this is only because we have chosen a direction for looking, namely what we call the top direction. If, on the other had we were to look at the same diagram from the back of the paper you would say that the motion is clockwise! Just try it. But your question still stands in the sense that if you were to ask why all the planets in the solar system revolve in the same direction. The explanation for this can be found through a realisation that the sun and its planets all arose from the contraction of a large cloud of gas and dust that was slowly rotating. The direction rotation of that initial cloud would then determine the direction of spin of the sun as also of the pieces of that cloud that accreted to form various planets. This direction of orbital motion of all the planets and of the spin of the sun has a common inheritance, and therefore the same. If an object is transparent then no shadow will be formed. However, I saw a shadow of a stream of water flowing through a pipe. How? If a medium through which light passes is transparent, it does not simultaneously imply that the light cannot be bent while going through it. A prism made out of glass that is quite transparent can still break up white light into seven colours. (Colours result from the fact that the components of light of different wavelengths bend differently in going through the prism). When a stream of water flows through a pipe might have different thickness across its cross section, or might have varying non-uniform thickness, even portions where there are air pockets. It is because of this reason that it does not appear transparent. Being transparent does not mean completely non-interacting.
Readers wanting to ask Prof Yash Pal a question can e-mail him at palyash.pal@gmail.com
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Trends
OSLO: Space agencies and Google Inc are helping an international project to monitor forests by satellite to fight global warming, the head of an international earth observation group said on Tuesday. Deforestation from Brazil to Indonesia is blamed for emitting about a fifth of all greenhouse gases from human activities — plants soak up carbon as they grow and release it when they burn or rot. Scientists glean lessons from stalled AIDS vaccine PARIS: Merck and Co’s failed AIDS vaccine may not have worked, but it probably did not raise the risk of infection either, doctors said on Tuesday. Data analyzed after the large clinical trial was stopped in 2007 contradict earlier findings that suggested some groups, such as uncircumcised men, may have been more vulnerable to infection if they got the vaccine, Dr. Susan Buchbinder of
the San Francisco Department of Public Health told an AIDS vaccine conference.
— Reuters |
Global food production needs to be increased by between 50 and 100 per cent if widespread famine is to be avoided in the coming decades as the human population expands rapidly, leading scientists said.