Top scientists have a better idea of how global warming will shape the 21st century: In a new report, they predict sea levels will be much higher than previously thought and pinpoint how dangerously hot it's likely to get.
In its most strongly worded report yet, an international climate panel said it was more confident than ever that global warming is a man-made problem and likely to get worse. The report was welcomed by the Obama administration and environmental advocates who said it made a strong and urgent case for government action, while skeptics scoffed at it.
"There is something in this report to worry everyone," said Chris Field, a Carnegie Institution scientist who is a leader of the Intergovernmental Panel on Climate Change but wasn't involved in the report released Friday.
Without any substantial changes, he said the world is now on track for summers at the end of the century that are hotter than current records, sea levels that are much higher, deluges that are stronger and more severe droughts.
The Nobel Prize-winning panel's report called the warming of the planet since 1950 "unequivocal" and "unprecedented" and blamed increases in heat-trapping greenhouse gases such as carbon dioxide from the burning of coal, oil and gas.
The United Nations created the panel of climate researchers in 1990 to tell world leaders what science is saying about global warming and how bad it will get. This is the group's fifth major state-of-the-science report, approved by nearly 200 nations at the end of a weeklong meeting in Stockholm.
In its last massive report in 2007, the panel said it was "very likely" -- or 90 percent certain -- that global warming was due to human activity, particularly carbon dioxide from things like coal-burning power plants and car exhaust. The new report moves that to 95 percent or "extremely likely."
The panel also fine-tuned its predictions for temperature changes and sea levels by the end of this century. Their worst case scenario previously put sea levels increase at just shy of 2 feet (59 centimeters) by 2100; now they put it at slightly more than 3 feet (1 meter). They cite better understanding of how much glaciers and ice sheets are melting and how water expands as it warms.
Unless the world drastically cuts emissions -- an event scientists called highly unlikely to happen -- the panel said Earth will warm by at least 2 more degrees Fahrenheit (1.1 degrees Celsius) this century in all but one of the four scenarios they outline. (continued...)
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Posted: 2013-09-30 @ 2:37pm PT
Why use 21st Century AD garbage in - garbage out computers, when a 4th Century BC human already proved Earth's natural cycles with an eyewitness weather account before thermometers were invented?
"So the sea will never dry up: for before that can happen the water that has gone up beforehand will return to it: for if you say that this happens once you must admit its recurrence. If you stop the sun's course there is no drying agency. If you let it go on it will draw up the sweet water as we have said whenever it approaches, and let it descend again when it recedes. This notion about the sea is derived from the fact that many places are found to be drier now than they once were. Why this is so we have explained. The phenomenon is due to temporary excess of rain and not to any process of becoming in which the universe or its parts are involved. Some day the opposite will take place and after that the earth will grow dry once again. We must recognize that this process always goes on thus in a cycle, for that is more satisfactory than to suppose a change in the whole world in order to explain these facts. But we have dwelt longer on this point than it deserves."
Meteorology By Aristotle
Written 350 B.C.E
Translated by E. W. Webster