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in the decade when 1 was the lead reporteron climate change for the New York Times,.nearly every blizzard or cold wave that hitthe Northeast would bring the same conversationat work.
Somebody in the newsroom would eye meand say something like, "So much for globalwarming." This would often, but not always,be accompanied by teasing or maliciousexpressions, and depending on my mood theperson would get either a joking or snappishor explanatory response. Now, such exchangesmight still happen, but most of them must havegiven way to silence of certainty.
On October 12, 2007, A1 Gore and theU.N.'s Intergovernmental Panel on ClimateChange (IPCC) were awarded the 2007 NobelPeace Prize. If, as they say, Gore has been thelead singer on climate change for years, theIPCC-a group of more than 2,000 scientistsfrom around the world--has been his chorus.Established by the UN in 1988 as the finalscientific authority on global warming, the IPCChas issued four assessments--the most recent in2007-taking the current temperature of climatechange. Reading the successive reports, whichgrow more and more confident about the realityand the danger of climate change, is like seeingan image fall into focus.
▲In 1990, in its first report, the panel found evidence ofglobal warming but said its cause could be natural as easily ashuman.
▲In a landmark 1995 report, the panel altered its judgment,saying that "the balance of evidence suggests a discerniblehuman influence on global climate."
▲In 2001, it placed the probability that human activitycaused most of the warming of the previous half century at 66percent to 90 percent-a "likely" rating.
▲In 2007, it declared that the evidence of a warming trendis "unequivocal," and that human activity has"very likely" been the driving force in thatchange over the last 50 years. It certified that11 of the last 12 years were among the 12warmest on record worldwide.
In temperate zones, the frequency of colddays, cold nights and frosts has diminished,while the frequency of hot days, hot nightsand heat waves has increased. Droughts insome parts of the world have become longerand more intense. Precipitation has decreasedover the subtropics and most of the tropics,but increased elsewhere in the Northern andSouthern Hemispheres.
There have been widespread increases in the frequencyof"heavy precipitation events," even in areas where overallprecipitation has gone down. What this means is that inmany places, it rains and snows less often but harderwell-documented characteristics of a warming atmosphere.Remember this in the future, when the news media reportheavy, sometimes catastrophic one-day rainfalls-four,six, eight inches as has often happened in the UnitedStates in recent years.
The list goes on.
And for the first time, in the wake of HurricaneKatrina, the panel reported evidence of a trend toward more intense hurricanes since 1970, and said it was likelythat this trend, too, would continue.
Some of the panel's main conclusions have remainedfairly stable over the years. One is that if greenhouse gasemissions continue unabated, they will most likely warmthe earth by about 3 to 7 degrees Fahrenheit by the end ofthis century, with a wider range of about 2 to 12 degreespossible. The warming over the Northern Hemisphere isprojected to be higher than the global average, as is thecase for the modest one-degree warming observed in thelast century.
Some experts believe that no matter whathumans do to try to rein in greenhouse gasemissions, a doubling is all but inevitable by 2 I00.In this view, the urgent task ahead is to keep themfrom rising even higher.
If the concentrations were to triple, and evenif they just double, there is no telling at this pointwhat the world will really be like as a result, exceptto speculate that on balance, most of its inhabitantsprobably won't like ir much. If James E. Hansen,one of the bolder climate scientists of the last twodecades, is right, they will be living on a differentplanet.
It has been pointed out many times, includingby me, that we are engaged in a titanic globalexperiment. The further it proceeds, the clearerthe picture should become. At age 71. I'm unlikelyto be around when it resolves to everyone'ssatisfaction or dissatisfaction. Many of you maybe. and a lot of your descendants undoubtedly willbe.
Good luck to you and to them.
Somebody in the newsroom would eye meand say something like, "So much for globalwarming." This would often, but not always,be accompanied by teasing or maliciousexpressions, and depending on my mood theperson would get either a joking or snappishor explanatory response. Now, such exchangesmight still happen, but most of them must havegiven way to silence of certainty.
On October 12, 2007, A1 Gore and theU.N.'s Intergovernmental Panel on ClimateChange (IPCC) were awarded the 2007 NobelPeace Prize. If, as they say, Gore has been thelead singer on climate change for years, theIPCC-a group of more than 2,000 scientistsfrom around the world--has been his chorus.Established by the UN in 1988 as the finalscientific authority on global warming, the IPCChas issued four assessments--the most recent in2007-taking the current temperature of climatechange. Reading the successive reports, whichgrow more and more confident about the realityand the danger of climate change, is like seeingan image fall into focus.
▲In 1990, in its first report, the panel found evidence ofglobal warming but said its cause could be natural as easily ashuman.
▲In a landmark 1995 report, the panel altered its judgment,saying that "the balance of evidence suggests a discerniblehuman influence on global climate."
▲In 2001, it placed the probability that human activitycaused most of the warming of the previous half century at 66percent to 90 percent-a "likely" rating.
▲In 2007, it declared that the evidence of a warming trendis "unequivocal," and that human activity has"very likely" been the driving force in thatchange over the last 50 years. It certified that11 of the last 12 years were among the 12warmest on record worldwide.
In temperate zones, the frequency of colddays, cold nights and frosts has diminished,while the frequency of hot days, hot nightsand heat waves has increased. Droughts insome parts of the world have become longerand more intense. Precipitation has decreasedover the subtropics and most of the tropics,but increased elsewhere in the Northern andSouthern Hemispheres.
There have been widespread increases in the frequencyof"heavy precipitation events," even in areas where overallprecipitation has gone down. What this means is that inmany places, it rains and snows less often but harderwell-documented characteristics of a warming atmosphere.Remember this in the future, when the news media reportheavy, sometimes catastrophic one-day rainfalls-four,six, eight inches as has often happened in the UnitedStates in recent years.
The list goes on.
And for the first time, in the wake of HurricaneKatrina, the panel reported evidence of a trend toward more intense hurricanes since 1970, and said it was likelythat this trend, too, would continue.
Some of the panel's main conclusions have remainedfairly stable over the years. One is that if greenhouse gasemissions continue unabated, they will most likely warmthe earth by about 3 to 7 degrees Fahrenheit by the end ofthis century, with a wider range of about 2 to 12 degreespossible. The warming over the Northern Hemisphere isprojected to be higher than the global average, as is thecase for the modest one-degree warming observed in thelast century.
Some experts believe that no matter whathumans do to try to rein in greenhouse gasemissions, a doubling is all but inevitable by 2 I00.In this view, the urgent task ahead is to keep themfrom rising even higher.
If the concentrations were to triple, and evenif they just double, there is no telling at this pointwhat the world will really be like as a result, exceptto speculate that on balance, most of its inhabitantsprobably won't like ir much. If James E. Hansen,one of the bolder climate scientists of the last twodecades, is right, they will be living on a differentplanet.
It has been pointed out many times, includingby me, that we are engaged in a titanic globalexperiment. The further it proceeds, the clearerthe picture should become. At age 71. I'm unlikelyto be around when it resolves to everyone'ssatisfaction or dissatisfaction. Many of you maybe. and a lot of your descendants undoubtedly willbe.
Good luck to you and to them.