THE POSSIBILITY OF A "RUNAWAY" GLOBAL WARMING
Dr. Jeremy Leggett
1.LINK IT:
Part One written by Dr. Jeremy Leggett, who took his PhD in earth sciences at the University of Oxford in 1978, and joined the faculty at Imperial College of Science and Technology, where during an 11 year career he won two major awards for his research on the geological history of oceans, sat on several advisory committees for the UK government's Natural Environment Research Council, and consulted for the oil industry in the UK and Japan.
In September 2000, world-renowned physicist Stephen Hawking was widely quoted in the press as being very worried about "runaway global warming." (See story below) "I am afraid the atmosphere might get hotter and hotter until it will be like Venus with boiling sulfuric acid," said Hawking. "I am worried about the greenhouse effect."
The planet Venus is indeed a frightening example of what scientists call "runaway global warming." Venus actually had oceans of water at one time, but now is an intense 900ºF, which has boiled away all surface water. Astronomers attribute the extreme hotness of Venus's atmospheric temperature to the occurrence of a runaway greenhouse effect on Venus. Ninety-six percent of Venus's atmosphere is now carbon dioxide - a powerful greenhouse gas. On Venus (and on Earth), sunlight passes through the atmosphere as visible light, which warms up the surface of the planet. On Earth, some of this surface heat is then radiated back into space, mostly in infrared wavelengths. But unlike visible light waves, infrared waves can't pass through Venus's atmosphere back into space because they are blocked by the huge amount of carbon dioxide and other greenhouse gases in its atmosphere. As a result, the heat is "trapped" in Venus atmosphere, causing it to be the hottest place in the solar system. And Venus keeps getting hotter as more sunlight hits it every day. Even' worse, scientists say the "runaway greenhouse effect" on Venus could continue indefinitely.
So why is Stephen Hawking worried about Earth becoming like Venus? He's worried because if all of the carbon dioxide, methane, and other greenhouse gases currently trapped in Earth's oceans and other greenhouse gas "sinks" were released into the atmosphere through the positive feedback mechanisms discussed in the articles below, our atmosphere would have as much carbon dioxide and other greenhouse gases as Venus now does. The effects of that on global climate could be profound - like what has happened on Venus, runaway global warming could conceivably make Earth so hot that life as we know it could no longer survive.
The vast majority of the world's climate scientists agree that global warming is now occurring on Earth due to the release of carbon dioxide and other greenhouse gases into the atmosphere by the burning of fossil fuels and other human activities. It is not certain that the present global warming will "runaway" and cause a catastrophic climate change such as that which has made Venus uninhabitable, but, as is discussed in the articles below, it is considered a possibility. The question is, do we want to play what is basically a form of Russian roulette with life on Earth by continuing to pour greenhouse gases into the atmosphere on the gamble that runaway global warming won't happen? (06/01/1992) Scientists fear a coalescing pattern of positive global warming feedbacks could cause "runaway" global warming, threatening the entire basis for life on Earth. Scientific consensus on global warming was formalized in May 1990 in an assessment by the Intergovernmental Panel on Climate Change (IPCC). Its authoritative early warning set most of the world's governments negotiating for a Global Climate Convention in February 1991. Amid rapid advances in scientific research, the IPCC was asked to prepare an updated report by January 1992.
When climate scientists gathered in Guangzhou, China, to complete the second IPCC report, the political scrutiny was intense. Some governments (like Germany and Austria) looked for confirmation that their policies of cutting carbon dioxide emissions - the gas is modern civilization's major contributor to global warming - were sound. Foot-dragging governments (like the United States and Saudi Arabia) sought evidence for their arguments that uncertainties about global warming permit delays in efforts to cut greenhouse gas emissions.
3.Some facts:I feel everybody can save global only have a heart then you everybody can do.
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