Perils of global warming and search for green technology
Saturday, 8 December 2007
Syed Fattahul Alim
At the UN climate change conference in Bali scientists have again expressed their deep concern about the consequences of unchecked green house gas (GHG) emission which might lead to extreme conditions such as droughts, flooding and rise in sea level globally.
Urging that a new international deal on climate change has to be reached to ensure that global warming may not rise more than 2 degrees centigrade above the pre-industrial level. And whatever needs to be done has to be done within the next 10 to 15 years. That in other words means the emission of the GHGs must peak and decline within this deadline. The target should be to cut at least by 50 per cent by 2050. The warning at Bali has been issued after thousands of scientists working under the UN's Intergovernmental Panel on Climate Change came up with their assessment that the global warming was 'unequivocal' and the chief cause behind this is human action.
Emission of GHG gases is not the sole reason for global warming and other climate changing conditions. For example, deforestation caused by indiscriminate felling of trees from the big natural forests in the different parts of the world is also accelerating the pace climate change. The Amazon rain forest is one of the places on earth that is still trying to maintain the earth's ecological balance. But that rain forest, too, is under big threat from unscrupulous human action.
Narrated below is the Amazon rain forest which is being decimated and if this destruction goes on unchecked 60 per cent of the forest might be wiped out by 2030. Alison Benjamin of the Guardian reports in detail how that tragedy is being enacted before our own eyes.
"Climate change could speed up the large-scale destruction of the Amazon rainforest and bring the "point of no return" much closer than previously thought, conservationists warned today.
Almost 60 per cent of the region's forests could be wiped out or severely damaged by 2030, as a result of climate change and deforestation, according to a report published today by WWF.
The damage could release somewhere between 55.5bn-96.9bn tons of carbon dioxide into the atmosphere from the Amazon's forests and speed up global warming, according to the report, Amazon's Vicious Cycles: Drought and Fire.
Trends in agriculture and livestock expansion, fire, drought and logging could severely damage 55 per cent of the Amazon rainforest by 2030, the report says. And, in turn, climate change could speed up the process of destruction by reducing rainfall by as much as 10 per cent by 2030, damaging an extra 4 per cent of the forests during that time.
By the end of the century, global warming is likely to reduce rainfall by 20 per cent in eastern Amazonia, pushing up temperatures by more than 2C and causing forest fires, the report said.
Destroying almost 60 per cent of tropical rainforest by 2030 would do away with one of the key stabilisers of the global climate system, it warned.
Such damage could have a knock-on effect on rainfall in places such as central America and India, and would also destroy livelihoods for indigenous people and some 80 per cent of habitats for animal species in the region.
The "point of no return", in which extensive degradation of the rainforest occurs and conservation prospects are greatly reduced, is just 15-25 years away - much sooner than some models suggest, the report warns.
Releasing the report at the UN conference in Bali, which aims to begin negotiations on a new international climate change deal, the WWF called for a strategy to reduce emissions from forests and stop deforestation.
Beatrix Richards, the head of forests at WWF-UK, said: "The Amazon is on a knife-edge due to the dual threats of deforestation and climate change.
"Developed countries have a key role to play in throwing a lifeline to forest around the world. At the international negotiations currently underway in Bali governments must agree a process which results in ambitious global emission reduction targets beyond the current phase of Kyoto which ends in 2012.
"Crucially this must include a strategy to reduce emissions from forests and help break the cycle of deforestation."
The report's author, Dan Nepstead, senior scientist at the Woods Hole research centre in Massachusetts, said: "The importance of the Amazon forest for the globe's climate cannot be underplayed.
"It's not only essential for cooling the world's temperature but such a large source of freshwater that it may be enough to influence some of the great ocean currents, and on top of that it's a massive store of carbon."
With global efforts to bring down GHG emissions, scientists are also working tirelessly develop technologies that are clean and based the use of renewable energy. James Randerson of Guardian tells how laser technology is coming in aid of man's search for cleaner technology.
"Laser fusion Magnetic fusion has long been heralded as the future of renewable energy, but could it be lasers that hold the key? James Randerson looks into science's latest power saviour
It's a clean source of energy using fuel that can easily be extracted from sea water, and it isn't owned by Saudi Arabia. We're talking about fusion - and a multinational project led by British researchers that aims to use high-powered lasers to produce nuclear fusion, the same physical reaction powering the sun. If they succeed, they could solve the approaching world energy crisis without destroying the environment.
Although the team admits a commercial fusion reactor is still decades away, it believes using lasers to spark fusion shows great promise. The EU has agreed to fund the setup costs for a seven-year research project called HiPER (High Powered laser Energy Research) to build a working demonstration reactor. But preparing for that stage - requiring the collaboration of 11 nations including Germany, France, Canada and Russia - is expected to cost more than €50m (£35m). Building the reactor itself will cost more than €500m.
Money machine
Why such investment? Because if we can control a fusion generator, it will be self-powering, offering abundant excess energy (to convert in turn to electricity) from virtually unlimited fuel. On top of this, its waste products won't contribute to climate change or pose the long-term waste storage problem that fission - our present nuclear generation system - poses. And we desperately need new electricity sources.
But fusion is infamous for its grand claims, massive grant proposals and, so far, limited success. Physicists joke that they've been saying fusion power is 40 years away for the past 40 years. So far it's only been used in the H-bombs exploded in tests, but that was uncontrolled.
Up to now, most attention has been on so-called magnetic fusion, in which a powerful magnetic jacket brings two different isotopes of hydrogen at enormously high temperatures close enough to fuse. That releases huge amounts of energy. It's been done - but no reactor has been built large enough to generate more energy than is put in via the magnets.
From the lab to reality
The HiPER team knows its approach can work. US experiments with underground nuclear explosions in the 1980s showed if you deliver enough energy to a pellet of hydrogen, fusion will occur. Laser fusion just needs to replicate that in the lab, using a high-powered laser, not a bomb.
A huge US military experiment at Livermore in California called the National Ignition Facility aims to do this in the next two years. Once done, the HiPER team wants to leapfrog the American effort. "This is how to take it from a scientific demonstration to a commercial reality," says Professor Mike Dunne, director of the UK's Central Laser Facility (CLF) in Oxfordshire and an instigator of the HiPER project.
Laser fusion involves some mind-numbing science. CLF's laser, called Vulcan, is the most powerful laser in the world: it can focus 500 joules of energy (about the same required to lift 50 apples by 10m) into a laser burst just 40 femtoseconds (40 x 10-15) long - equivalent to one second in a million years. During that period, it's applying 10,000 times more energy than the National Grid generates.
HiPER would use an even more powerful laser to set off a fusion reaction. The idea is to fire the laser at pellets of hydrogen that contain a mixture of the isotopes tritium and deuterium (which have three and two neutrons respectively). The intense power creates huge pressure - equivalent to 10 aircraft carriers resting on your thumb, claims Dunne - making the pellet implode until it has 20 times the density of lead, and the hydrogen nuclei fuse to form helium and release energy. Harder still, the laser must be fired five times per second, aimed at pellets being released at precisely the same rate. The engineering challenge is immense.
In principle, fusion is much safer than its cousin nuclear fission. Unlike fission, which tears apart atomic nuclei, only low-level radioactive material is left over - no more dangerous than hospital waste. And best of all, a runaway chain reaction like the one that caused the Chernobyl meltdown is simply impossible. "At any given point in time there is not much energy in a pellet of fuel; the worst that can happen is it doesn't work," Dunne says.
The other plus is that the raw materials for fusion are cheap and easily obtainable. There is an almost limitless supply of deuterium in sea water, and tritium is a by-product of the fusion reactor itself.
Crossing the finishing line
So will magnetic or laser get there first? That depends on who you talk to. Dunne is convinced that the ability to solve problems in parallel gives laser fusion a distinct edge; unlike magnetic fusion, progress does not depend on the whole machine being up and running.
At the moment high-powered lasers need a few minutes to recharge between firing; in a laser fusion reactor they'll need to fire five times a second. What's more, they're typically 2 per cent efficient, so this will need to improve by a factor of 10 if fusion is to be a realistic possibility.
At the UN climate change conference in Bali scientists have again expressed their deep concern about the consequences of unchecked green house gas (GHG) emission which might lead to extreme conditions such as droughts, flooding and rise in sea level globally.
Urging that a new international deal on climate change has to be reached to ensure that global warming may not rise more than 2 degrees centigrade above the pre-industrial level. And whatever needs to be done has to be done within the next 10 to 15 years. That in other words means the emission of the GHGs must peak and decline within this deadline. The target should be to cut at least by 50 per cent by 2050. The warning at Bali has been issued after thousands of scientists working under the UN's Intergovernmental Panel on Climate Change came up with their assessment that the global warming was 'unequivocal' and the chief cause behind this is human action.
Emission of GHG gases is not the sole reason for global warming and other climate changing conditions. For example, deforestation caused by indiscriminate felling of trees from the big natural forests in the different parts of the world is also accelerating the pace climate change. The Amazon rain forest is one of the places on earth that is still trying to maintain the earth's ecological balance. But that rain forest, too, is under big threat from unscrupulous human action.
Narrated below is the Amazon rain forest which is being decimated and if this destruction goes on unchecked 60 per cent of the forest might be wiped out by 2030. Alison Benjamin of the Guardian reports in detail how that tragedy is being enacted before our own eyes.
"Climate change could speed up the large-scale destruction of the Amazon rainforest and bring the "point of no return" much closer than previously thought, conservationists warned today.
Almost 60 per cent of the region's forests could be wiped out or severely damaged by 2030, as a result of climate change and deforestation, according to a report published today by WWF.
The damage could release somewhere between 55.5bn-96.9bn tons of carbon dioxide into the atmosphere from the Amazon's forests and speed up global warming, according to the report, Amazon's Vicious Cycles: Drought and Fire.
Trends in agriculture and livestock expansion, fire, drought and logging could severely damage 55 per cent of the Amazon rainforest by 2030, the report says. And, in turn, climate change could speed up the process of destruction by reducing rainfall by as much as 10 per cent by 2030, damaging an extra 4 per cent of the forests during that time.
By the end of the century, global warming is likely to reduce rainfall by 20 per cent in eastern Amazonia, pushing up temperatures by more than 2C and causing forest fires, the report said.
Destroying almost 60 per cent of tropical rainforest by 2030 would do away with one of the key stabilisers of the global climate system, it warned.
Such damage could have a knock-on effect on rainfall in places such as central America and India, and would also destroy livelihoods for indigenous people and some 80 per cent of habitats for animal species in the region.
The "point of no return", in which extensive degradation of the rainforest occurs and conservation prospects are greatly reduced, is just 15-25 years away - much sooner than some models suggest, the report warns.
Releasing the report at the UN conference in Bali, which aims to begin negotiations on a new international climate change deal, the WWF called for a strategy to reduce emissions from forests and stop deforestation.
Beatrix Richards, the head of forests at WWF-UK, said: "The Amazon is on a knife-edge due to the dual threats of deforestation and climate change.
"Developed countries have a key role to play in throwing a lifeline to forest around the world. At the international negotiations currently underway in Bali governments must agree a process which results in ambitious global emission reduction targets beyond the current phase of Kyoto which ends in 2012.
"Crucially this must include a strategy to reduce emissions from forests and help break the cycle of deforestation."
The report's author, Dan Nepstead, senior scientist at the Woods Hole research centre in Massachusetts, said: "The importance of the Amazon forest for the globe's climate cannot be underplayed.
"It's not only essential for cooling the world's temperature but such a large source of freshwater that it may be enough to influence some of the great ocean currents, and on top of that it's a massive store of carbon."
With global efforts to bring down GHG emissions, scientists are also working tirelessly develop technologies that are clean and based the use of renewable energy. James Randerson of Guardian tells how laser technology is coming in aid of man's search for cleaner technology.
"Laser fusion Magnetic fusion has long been heralded as the future of renewable energy, but could it be lasers that hold the key? James Randerson looks into science's latest power saviour
It's a clean source of energy using fuel that can easily be extracted from sea water, and it isn't owned by Saudi Arabia. We're talking about fusion - and a multinational project led by British researchers that aims to use high-powered lasers to produce nuclear fusion, the same physical reaction powering the sun. If they succeed, they could solve the approaching world energy crisis without destroying the environment.
Although the team admits a commercial fusion reactor is still decades away, it believes using lasers to spark fusion shows great promise. The EU has agreed to fund the setup costs for a seven-year research project called HiPER (High Powered laser Energy Research) to build a working demonstration reactor. But preparing for that stage - requiring the collaboration of 11 nations including Germany, France, Canada and Russia - is expected to cost more than €50m (£35m). Building the reactor itself will cost more than €500m.
Money machine
Why such investment? Because if we can control a fusion generator, it will be self-powering, offering abundant excess energy (to convert in turn to electricity) from virtually unlimited fuel. On top of this, its waste products won't contribute to climate change or pose the long-term waste storage problem that fission - our present nuclear generation system - poses. And we desperately need new electricity sources.
But fusion is infamous for its grand claims, massive grant proposals and, so far, limited success. Physicists joke that they've been saying fusion power is 40 years away for the past 40 years. So far it's only been used in the H-bombs exploded in tests, but that was uncontrolled.
Up to now, most attention has been on so-called magnetic fusion, in which a powerful magnetic jacket brings two different isotopes of hydrogen at enormously high temperatures close enough to fuse. That releases huge amounts of energy. It's been done - but no reactor has been built large enough to generate more energy than is put in via the magnets.
From the lab to reality
The HiPER team knows its approach can work. US experiments with underground nuclear explosions in the 1980s showed if you deliver enough energy to a pellet of hydrogen, fusion will occur. Laser fusion just needs to replicate that in the lab, using a high-powered laser, not a bomb.
A huge US military experiment at Livermore in California called the National Ignition Facility aims to do this in the next two years. Once done, the HiPER team wants to leapfrog the American effort. "This is how to take it from a scientific demonstration to a commercial reality," says Professor Mike Dunne, director of the UK's Central Laser Facility (CLF) in Oxfordshire and an instigator of the HiPER project.
Laser fusion involves some mind-numbing science. CLF's laser, called Vulcan, is the most powerful laser in the world: it can focus 500 joules of energy (about the same required to lift 50 apples by 10m) into a laser burst just 40 femtoseconds (40 x 10-15) long - equivalent to one second in a million years. During that period, it's applying 10,000 times more energy than the National Grid generates.
HiPER would use an even more powerful laser to set off a fusion reaction. The idea is to fire the laser at pellets of hydrogen that contain a mixture of the isotopes tritium and deuterium (which have three and two neutrons respectively). The intense power creates huge pressure - equivalent to 10 aircraft carriers resting on your thumb, claims Dunne - making the pellet implode until it has 20 times the density of lead, and the hydrogen nuclei fuse to form helium and release energy. Harder still, the laser must be fired five times per second, aimed at pellets being released at precisely the same rate. The engineering challenge is immense.
In principle, fusion is much safer than its cousin nuclear fission. Unlike fission, which tears apart atomic nuclei, only low-level radioactive material is left over - no more dangerous than hospital waste. And best of all, a runaway chain reaction like the one that caused the Chernobyl meltdown is simply impossible. "At any given point in time there is not much energy in a pellet of fuel; the worst that can happen is it doesn't work," Dunne says.
The other plus is that the raw materials for fusion are cheap and easily obtainable. There is an almost limitless supply of deuterium in sea water, and tritium is a by-product of the fusion reactor itself.
Crossing the finishing line
So will magnetic or laser get there first? That depends on who you talk to. Dunne is convinced that the ability to solve problems in parallel gives laser fusion a distinct edge; unlike magnetic fusion, progress does not depend on the whole machine being up and running.
At the moment high-powered lasers need a few minutes to recharge between firing; in a laser fusion reactor they'll need to fire five times a second. What's more, they're typically 2 per cent efficient, so this will need to improve by a factor of 10 if fusion is to be a realistic possibility.