TerraN_EmpirE
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voice oneUN climate change report dismisses slowdown in global warming
Published September 27, 2013 | FoxNews.com
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The Earth has changed in “unprecedented ways” since 1950, the U.N. says, and its scientists are 95 percent certain that humans are responsible.
Yet the planet has largely stopped warming over the past 15 years, data shows -- and a landmark report released Friday by the U.N.’s climate group could not explain why the mercury has stopped rising.
Global surface temperatures rose rapidly during the 70s, but have been relatively flat over the past decade and a half, rising only 0.05 degrees Celsius (0.09 degrees Fahrenheit) per decade according to data from the U.K.’s weather-watching Met Office, a trend current models of the world’s climate have been unable to predict. A draft of the report leaked in early September acknowledged that trend and put it bluntly: We simply can’t explain it.
“Models do not generally reproduce the observed reduction in surface warming trend over the last 10–15 years.”
But a final version of the report released Friday morning by the U.N.’s Intergovernmental Panel on Climate Change (IPCC) strips out the failure of models and explains away the downward trend.
“Due to natural variability, trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends,” the new report reads.
A later reference suggests volcanoes, oceans and solar activity may have affected the warming, although the IPCC said it wasn't confident in that finding.
The U.N. arm also acknowledges another possibility: Maybe it was wrong.
"There may also be ... an overestimate of the response to increasing greenhouse gas and other anthropogenic forcing," the new report admits.
Climate skeptics have seized upon the change in world weather patterns, some citing it as evidence that global warming itself has decelerated or even stopped. Benny Peiser, director of the Global Warming Policy Foundation, said the slowdown was a far larger issue than the report shows.
“Unless global temperature will begin to rise again in the next few years, the IPCC is very likely going to suffer an existential blow to its credibility,” he said. Judith Curry, professor and chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, was even blunter.
“IPCC has thrown down the gauntlet – if the pause continues beyond 15 years (well it already has), they are toast.”
Many governments had objections over how the issue was treated in earlier drafts and some had called for it to be deleted altogether. In a Friday morning presentation of its findings, Thomas Stocker, co-chair of the group that wrote the report, defended that decision, the Associated Press reported.
"An old rule says that climate-relevant trends should not be calculated for periods less than around 30 years," Stocker said.
Many scientists say the slowdown reflects random climate fluctuations and an unusually hot year, 1998, picked as a starting point for charting temperatures. Another leading hypothesis is that heat is settling temporarily in the oceans.
Stocker said there wasn't enough literature on "this emerging question."
The IPCC said the evidence of climate change has grown thanks to more and better observations, a clearer understanding of the climate system and improved models to analyze the impact of rising temperatures.
"Our assessment of the science finds that the atmosphere and ocean have warmed, the amount of snow and ice has diminished, the global mean sea level has risen and the concentrations of greenhouse gases have increased," said Qin Dahe, co-chair of the working group that wrote the report.
Yet recent reports have stressed that climate models have failed to accurately predict global temperatures. A study in the journal Nature Climate Change compared 117 climate predictions made in the 1990's to the actual amount of warming. Out of 117 predictions, the study’s author told FoxNews.com, 3 were roughly accurate and 114 overestimated the amount of warming.
On average, the predictions forecasted two times more global warming than actually occurred.
"It's a real problem ... it shows that there really is something that needs to be fixed in the climate models," climate scientist John Christy, a professor at the University of Alabama in Huntsville, told FoxNews.com at the time.
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Voice twoScientists more convinced mankind is main cause of warming
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8:51pm EDT
By Alister Doyle and Simon Johnson
STOCKHOLM (Reuters) - Leading climate scientists said on Friday they were more convinced than ever that humans are the main culprits for global warming, and predicted the impact from greenhouse gas emissions could linger for centuries.
The Intergovernmental Panel on Climate Change (IPCC) said in a report that a hiatus in warming this century, when temperatures have risen more slowly despite growing emissions, was a natural variation that would not last.
It said the Earth was set for more heatwaves, floods, droughts and rising sea levels from melting ice sheets that could swamp coasts and low-lying islands as greenhouse gases built up in the atmosphere.
The study, meant to guide governments in shifting towards greener energies, said it was "extremely likely", with a probability of at least 95 percent, that human activities were the dominant cause of warming since the mid-20th century.
That was an increase from "very likely", or 90 percent, in the last report in 2007 and "likely", 66 percent, in 2001.
U.N. Secretary-General Ban Ki-moon said the study was a call for governments, many of which have been focused on spurring weak economies rather than fighting climate change, to work to reach a planned U.N. accord in 2015 to combat global warming.
"The heat is on. Now we must act," he said of the report agreed in Stockholm after a week of talks between scientists and delegates from more than 110 nations.
U.S. Secretary of State John Kerry said the report was a wake-up call. "Those who deny the science or choose excuses over action are playing with fire," he said, referring to skeptics who question the need for urgent action.
They have become emboldened by the fact that temperatures rose more slowly over the last 15 years despite increasing greenhouse gas emissions, especially in emerging nations led by China. Almost all climate models failed to predict the slowing.
"LOOKING FOR THE CURE"
European Climate Commissioner Connie Hedegaard said it was time to treat the Earth's health. "If your doctor was 95 percent sure you had a serious disease, you would immediately start looking for the cure," she said.
Compiled from the work of hundreds of scientists, the report faces extra scrutiny this year after its 2007 edition included an error that exaggerated the rate of melting of Himalayan glaciers. An outside review later found that the mistake did not affect its main conclusions.
The IPCC said some effects of warming would last far beyond current lifetimes.
Sea levels could rise by 3 meters (9 feet, 10 inches) under some scenarios by 2300 as ice melted and heat made water in the deep oceans expand, it said. About 15 to 40 percent of emitted carbon dioxide would stay in the atmosphere for more than 1,000 years.
"As a result of our past, present and expected future emissions of carbon dioxide, we are committed to climate change and effects will persist for many centuries even if emissions of carbon dioxide stop," said Thomas Stocker, co-chair of the talks.
The IPCC said humanity had emitted about 530 billion tons of carbon, more than half the 1 trillion ton budget it estimated as a maximum to keep warming to manageable limits. Annual emissions are now almost 10 billion tons and rising.
Explaining a recent slower pace of warming, the report said the past 15-year period was skewed by the fact that 1998 was an extremely warm year with an El Nino event - a warming of the ocean surface - in the Pacific.
It said warming had slowed "in roughly equal measure" because of random variations in the climate and the impact of factors such as volcanic eruptions, when ash dims sunshine, and a cyclical decline in the sun's output.
Rajendra Pachauri, chair of the IPCC, told Reuters the reduction in warming would have to last far longer - "three or four decades" - to be a sign of a new trend.
And the report predicted that the reduction in warming would not last, saying temperatures from 2016-35 were likely to be 0.3-0.7 degree Celsius (0.5 to 1.3 Fahrenheit) warmer than in 1986-2005.
Still, the report said the climate was slightly less sensitive than estimated to warming from carbon dioxide.
A doubling of carbon in the atmosphere would raise temperatures by between 1.5 and 4.5 degrees Celsius (2.7 to 8.1F), it said, below the 2-4.5 (3.6-8.1F) range in the 2007 report. The new range is identical to the ranges in IPCC studies before 2007.
The report said temperatures were likely to rise by between 0.3 and 4.8 degrees Celsius (0.5 to 8.6 Fahrenheit) by the late 21st century. The low end of the range would only be achieved if governments sharply cut greenhouse gas emissions.
And it said world sea levels could rise by between 26 and 82 cm (10 to 32 inches) by the late 21st century, in a threat to coastal cities from Shanghai to San Francisco.
That range is above the 18-59 cm estimated in 2007, which did not take full account of Antarctica and Greenland.
Bjorn Lomborg, author of "The Skeptical Environmentalist" said "the IPCC's moderate projections clearly contradict alarmist rhetoric" of higher temperature and sea level rises by some activists.
(Additional reporting by Nina Chestney in London, Barbara Lewis in Brussels, Valerie Volcovici in Washington; editing by Alistair Scrutton and Mark Trevelyan)
I recommend hunting down a copy and giving it a read.
