- Email: [email protected]
Why Antarctic ice is growing despite global warming
LARRY LEE/CORBIS
UPFRONT
Climate ‘cold war’ thaw? FEARS of a cold war on climate between China and the US, in which each waits for the other to budge first on greenhouse emissions, were replaced this week by sunnier hopes. In Washington, the Environmental Protection Agency has officially recognised carbon dioxide as a danger to human health. Although this may not result in direct regulation, it may prompt “cap and trade” laws, in which the government auctions emissions permits that can then be traded. “The greater significance may be that it will put more pressure on Congress to pass legislation,” says Bob Ward of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics. In Beijing, Chinese climate negotiators indicated on Monday that
at the UN climate conference in Copenhagen in December 2009, they may be prepared to offer a declared limit on future emissions – at least indirectly. China’s current five-year plan includes a target to reduce the “carbon intensity” of the Chinese economy by 20 per cent. That means it is reducing the amount of carbon burned for every dollar the economy makes. The next five-year plan is likely to include a further reduction, according to China’s top climate negotiator, Su Wei, who said the country could “very easily translate energy reduction targets to carbon dioxide limitation”. However, an actual reduction in emissions is unlikely for the near future, Su told The Guardian newspaper in London.
Dengue detectives
By repeating the experiment on each of the fruit fly’s 14,000 genes, they identified more than 100 genes necessary for infection to occur (Nature, DOI: 10.1038/nature07967). Further testing found that inhibiting 42 of the equivalent human genes stopped dengue fever from infecting human cells, suggesting targets for drug treatment. The team also identified a gene necessary for dengue fever to infect its host, the Aedes aegypti mosquito, potentially leading to new ways to prevent transmission.
–The US and China are shifting their stance–
Ozone with ice
“The ozone hole has generated strong storms around the Ross Sea, where new ice has formed” Antarctica. They found that depletion of ozone has intensified strong winds that swirl around the continent. This vortex has drawn more warm air in from 4 | NewScientist | 25 April 2009
L. CALÇADA/ESO
BLAME the southern ozone hole. That’s why Antarctic sea ice is growing even though Arctic ice is shrinking at record rates. It seems CFCs and other ozonedepleting chemicals in the atmosphere have given the South Pole a respite from global warming. Satellite images studied by John Turner of the British Antarctic Survey and his colleagues show that Antarctic sea ice increases in every month except January. “We’re trying to understand why it’s increasing now, at a time of global warming,” says Turner. The researchers used an atmospheric model to investigate how the ozone hole has changed weather patterns around
Chile, which has warmed the Antarctic peninsula and may have contributed to the collapse of several ice shelves. However, it has also generated stronger cool-air storms around the Ross Sea, where new ice has formed. Overall, the increase in sea ice has been greater than the reduction (Geophysical Research Letters, DOI: 10.1029/2009GL037524, in press). The respite is temporary, though. The ozone hole will eventually close, Turner says. “In the next decade or so we should see sea ice plateauing and then decreasing massively.”
AS DENGUE fever struck Buenos Aires in Argentina for the first time this week, there is renewed hope that a drug to treat the 100 million people infected worldwide each year may one day be possible. Mariano Garcia-Blanco of Duke University Medical Center in Durham, North Carolina, and colleagues used RNA interference technology to “knock down” the activity of a gene in a fruit fly cell before exposing it to the dengue virus to assess the impact of this gene on infection.
Alien waterworld A PLANET orbiting a red dwarf star 20 light years away could be the first known waterworld, entirely covered by a deep ocean. The planet, named Gliese 581d, is not a new discovery, but its orbital period has now been revised from 83 to 66 days, putting it within the “habitable zone” where liquid water could exist on the surface. “It is the only low-mass planet known inside the habitable –Planetary system with a water feature– zone,” says Michel Mayor of the
UPFRONT
Climate ‘cold war’ thaw? FEARS of a cold war on climate between China and the US, in which each waits for the other to budge first on greenhouse emissions, were replaced this week by sunnier hopes. In Washington, the Environmental Protection Agency has officially recognised carbon dioxide as a danger to human health. Although this may not result in direct regulation, it may prompt “cap and trade” laws, in which the government auctions emissions permits that can then be traded. “The greater significance may be that it will put more pressure on Congress to pass legislation,” says Bob Ward of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics. In Beijing, Chinese climate negotiators indicated on Monday that
at the UN climate conference in Copenhagen in December 2009, they may be prepared to offer a declared limit on future emissions – at least indirectly. China’s current five-year plan includes a target to reduce the “carbon intensity” of the Chinese economy by 20 per cent. That means it is reducing the amount of carbon burned for every dollar the economy makes. The next five-year plan is likely to include a further reduction, according to China’s top climate negotiator, Su Wei, who said the country could “very easily translate energy reduction targets to carbon dioxide limitation”. However, an actual reduction in emissions is unlikely for the near future, Su told The Guardian newspaper in London.
Dengue detectives
By repeating the experiment on each of the fruit fly’s 14,000 genes, they identified more than 100 genes necessary for infection to occur (Nature, DOI: 10.1038/nature07967). Further testing found that inhibiting 42 of the equivalent human genes stopped dengue fever from infecting human cells, suggesting targets for drug treatment. The team also identified a gene necessary for dengue fever to infect its host, the Aedes aegypti mosquito, potentially leading to new ways to prevent transmission.
–The US and China are shifting their stance–
Ozone with ice
“The ozone hole has generated strong storms around the Ross Sea, where new ice has formed” Antarctica. They found that depletion of ozone has intensified strong winds that swirl around the continent. This vortex has drawn more warm air in from 4 | NewScientist | 25 April 2009
L. CALÇADA/ESO
BLAME the southern ozone hole. That’s why Antarctic sea ice is growing even though Arctic ice is shrinking at record rates. It seems CFCs and other ozonedepleting chemicals in the atmosphere have given the South Pole a respite from global warming. Satellite images studied by John Turner of the British Antarctic Survey and his colleagues show that Antarctic sea ice increases in every month except January. “We’re trying to understand why it’s increasing now, at a time of global warming,” says Turner. The researchers used an atmospheric model to investigate how the ozone hole has changed weather patterns around
Chile, which has warmed the Antarctic peninsula and may have contributed to the collapse of several ice shelves. However, it has also generated stronger cool-air storms around the Ross Sea, where new ice has formed. Overall, the increase in sea ice has been greater than the reduction (Geophysical Research Letters, DOI: 10.1029/2009GL037524, in press). The respite is temporary, though. The ozone hole will eventually close, Turner says. “In the next decade or so we should see sea ice plateauing and then decreasing massively.”
AS DENGUE fever struck Buenos Aires in Argentina for the first time this week, there is renewed hope that a drug to treat the 100 million people infected worldwide each year may one day be possible. Mariano Garcia-Blanco of Duke University Medical Center in Durham, North Carolina, and colleagues used RNA interference technology to “knock down” the activity of a gene in a fruit fly cell before exposing it to the dengue virus to assess the impact of this gene on infection.
Alien waterworld A PLANET orbiting a red dwarf star 20 light years away could be the first known waterworld, entirely covered by a deep ocean. The planet, named Gliese 581d, is not a new discovery, but its orbital period has now been revised from 83 to 66 days, putting it within the “habitable zone” where liquid water could exist on the surface. “It is the only low-mass planet known inside the habitable –Planetary system with a water feature– zone,” says Michel Mayor of the