WASHINGTON (Reuters) - The scientists who mind the Doomsday Clock moved it two minutes closer to midnight on Wednesday -- symbolizing the annihilation of civilization and adding the perils of global warming for the first time.
The Bulletin of the Atomic Scientists, which created the Doomsday Clock in 1947 to warn the world of the dangers of nuclear weapons, advanced the clock to five minutes until midnight. It was the first adjustment of the clock since 2002.
"We stand at the brink of a second nuclear age," the bulletin's board of directors said in a statement.
They pointed North Korea's first nuclear test, Iran's nuclear ambitions, U.S. flirtation with "bunker buster" nuclear bombs, the continued presence of 26,000 American and Russian nuclear weapons and inadequate security for nuclear materials.
But the scientists also said destruction of human habitats wreaked by climate change brought on by human activities is a growing danger.
"Global warming poses a dire threat to human civilization that is second only to nuclear weapons," they said.
The announcement was made in news conferences in London and Washington.
"We foresee great peril if governments and societies do not take action now to render nuclear weapons obsolete and to prevent further climate change," theoretical physicist Stephen Hawking of the University of Cambridge, a member of the bulletin's board of sponsors, told reporters in London.
'VILLAGE IDIOTS'
Cambridge astrophysicist Martin Rees added that while the Cold War confrontation between two nuclear-armed superpowers is over, the world is closer than ever to having nuclear bombs used in a localized war or by terrorists in a city center.
"A global village will have its village idiots," Rees said.
Kennette Benedict, the bulletin's executive director, dismissed the notion that by touting the threat posed by global warming, the scientists had diluted their message about the nuclear peril.
Many scientists predict dire consequences from global warming, including higher sea levels that over time could swamp coastal regions, more severe storms and worse wildfires. Human activities like burning of fossil fuels contribute to warming, they contend.
Physicist Lawrence Krauss of Case Western Reserve University in Cleveland said if humankind fails to change course on global warming, "there's a great possibility that the Earth in the year 2100 will only dimly resemble our planet today -- and as it has existed over the past 500,000 years."
The bulletin's scientists moved the clock two minutes forward in 2002, to seven minutes until midnight, following the September 11, 2001, attacks on the United States.
The bulletin was founded in 1945 by University of Chicago scientists who had worked on developing the first nuclear bomb, and it is now overseen by some of the world's most prominent scientists.
The bulletin created the clock in 1947, two years after the United States ushered in the nuclear age by dropping atomic bombs on two Japanese cities at the end of World War Two, to symbolize the urgent nuclear dangers confronting the world.
It now stands at the closest to midnight since 1984, when it was three minutes to midnight amid a deepening Cold War.
It has been adjusted 18 times in 60 years. It was set as close as two minutes to midnight in 1953 after the United States and Soviet Union tested hydrogen bombs, and as far as 17 minutes to midnight in 1991 at the Cold War's end.
By Will Dunham Wed Jan 17, 2:22 PM ET
Wednesday, January 17, 2007
Friday, January 05, 2007
Lost lakes of Titan are found at last
Lakes of methane have been spotted on Saturn's largest moon, Titan, boosting the theory that this strange, distant world bears beguiling similarities to Earth, according to a new study.
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Titan has long intrigued space scientists, as it is the only moon in the Solar System to have a dense atmosphere -- and its atmosphere, like Earth's, mainly comprises nitrogen.
Titan's atmosphere is also rich in methane, although the source for this vast store of hydrocarbons is unclear.
Methane, on the geological scale, has a relatively limited life. A molecule of the compound lasts several tens of millions of years before it is broken up by sunlight.
Given that Titan is billions of years old, the question is how this atmospheric methane gets to be renewed. Without replenishment, it should have disappeared long ago.
A popular hypothesis is that it comes from a vast ocean of hydrocarbons.
But when the US spacecraft Cassini sent down a European lander, Huygens, to Titan in 2005, the images sent back were of a rugged landscape veiled in an orange haze.
There were indeed signs of methane flows and methane precipitation, but nothing at all that pointed to any sea of the stuff.
But a flyby by Cassini on July 22 last year has revealed, thanks to a radar scan, 75 large, smooth, dark patches between three and 70 kilometers across (two and 42 miles) across that appear to be lakes of liquid methane, scientists report on Thursday.
They believe the lakes prove that Titan has a "methane cycle" -- a system that is like the water cycle on Earth, in which the liquid evaporates, cools and condenses and then falls as rain, replenishing the surface liquid.
As on Earth, Titan's surface methane may well be supplemented by a "table" of liquid methane that seeps through the rock, the paper suggests.
Some of the methane lakes seem only partly filled, and other depressions are dry, which suggests that, given the high northerly latitudes where they were spotted, the methane cycle follows Titan's seasons.
In winter, the lakes expand, while in summer, they shrink or dry up completely -- again, another parallel with Earth's hydrological cycle.
The study, which appears on Thursday in the British weekly journal Nature, is headed by Ellen Stofan of Proxemy Research in Virginia and University College London.
Titan and Earth are of course very different, especially in their potential for nurturing life. Titan is frigid, dark and, as far as is known, waterless, where as Earth is warm, light and has lots of liquid water.
But French astrophysicist Christophe Sotin says both our planet and Titan have been sculpted by processes that, fundamentally, are quite similar.
The findings "add to the weight of evidence that Titan is a complex world in which the interaction between the inner and outer layers is controlled by processes similar to those that must have dominated the evolution of any Earth-like planet," Sotin said in a commentary.
"Indeed, as far as we know," Sotin added, "there is only one planetary body that displays more dynamism than Titan. Its name is Earth."
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Titan has long intrigued space scientists, as it is the only moon in the Solar System to have a dense atmosphere -- and its atmosphere, like Earth's, mainly comprises nitrogen.
Titan's atmosphere is also rich in methane, although the source for this vast store of hydrocarbons is unclear.
Methane, on the geological scale, has a relatively limited life. A molecule of the compound lasts several tens of millions of years before it is broken up by sunlight.
Given that Titan is billions of years old, the question is how this atmospheric methane gets to be renewed. Without replenishment, it should have disappeared long ago.
A popular hypothesis is that it comes from a vast ocean of hydrocarbons.
But when the US spacecraft Cassini sent down a European lander, Huygens, to Titan in 2005, the images sent back were of a rugged landscape veiled in an orange haze.
There were indeed signs of methane flows and methane precipitation, but nothing at all that pointed to any sea of the stuff.
But a flyby by Cassini on July 22 last year has revealed, thanks to a radar scan, 75 large, smooth, dark patches between three and 70 kilometers across (two and 42 miles) across that appear to be lakes of liquid methane, scientists report on Thursday.
They believe the lakes prove that Titan has a "methane cycle" -- a system that is like the water cycle on Earth, in which the liquid evaporates, cools and condenses and then falls as rain, replenishing the surface liquid.
As on Earth, Titan's surface methane may well be supplemented by a "table" of liquid methane that seeps through the rock, the paper suggests.
Some of the methane lakes seem only partly filled, and other depressions are dry, which suggests that, given the high northerly latitudes where they were spotted, the methane cycle follows Titan's seasons.
In winter, the lakes expand, while in summer, they shrink or dry up completely -- again, another parallel with Earth's hydrological cycle.
The study, which appears on Thursday in the British weekly journal Nature, is headed by Ellen Stofan of Proxemy Research in Virginia and University College London.
Titan and Earth are of course very different, especially in their potential for nurturing life. Titan is frigid, dark and, as far as is known, waterless, where as Earth is warm, light and has lots of liquid water.
But French astrophysicist Christophe Sotin says both our planet and Titan have been sculpted by processes that, fundamentally, are quite similar.
The findings "add to the weight of evidence that Titan is a complex world in which the interaction between the inner and outer layers is controlled by processes similar to those that must have dominated the evolution of any Earth-like planet," Sotin said in a commentary.
"Indeed, as far as we know," Sotin added, "there is only one planetary body that displays more dynamism than Titan. Its name is Earth."
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