Friday, February 02, 2007

Global Warming Caused by Us, New Report Concludes

"We have this nailed," said climate scientist Jerry Mahlman. A new report on global warming compiled by hundreds of the world's leading climate scientists concludes that humans are causing the climate change that is melting ice caps and raising sea levels. The probability that human emissions are responsible was calculated to exceed 90%.

The report was issued today, Feb 2, from the Intergovernmental Panel on Climate Change. It can be seen by clicking here.

The Panel's previous report, in 2001, concluded that humans were "likely" the cause of planetary warming, with a 66% probability. But accumulating evidence has just about slammed the lid shut on that question.

Among the evidence cited in the new report:

  • 11 of the last 12 years rank among the 12 warmest years since humans have been recording surface temps with instruments (since 1850)
  • Balloon-borne and satellite measurements show tropospheric warming rates similar to those of surface warming rates
  • Water vapor content in surface air and in the troposphere has increased steadily since the 1980s, consistent with the extra water vapor that warmer air can hold
  • Since 1961, the ocean has been warming to a depth of at least 3000 meters, causing the water to expand, contributing (along with melting ice caps) to rising sea levels
  • Mountain glaciers and snow cover have declined in both hemispheres

Concluded the report: "Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level....The atmospheric concentration of CO2 has increased from a pre-industrial value of about 280 ppm to 379 ppm in 2005, far exceeding the natural range over the last 650,000 years (180 to 300 ppm)." The widespread warming of the globe and the loss of ice mass are more than 90% likely to be caused by human emissions, report the scientists.

How will we see these changes in weather events?

  • Warmer and fewer cold days and nights
  • Warmer and more frequent hot days and nights
  • Heavy precipitation events. Higher proportion of total rainfall from heavy falls, meaning higher runoff and more erosion, fewer penetrating rains.
  • Increase in areas affected by drought.
  • Increase in intense tropical cyclones.
  • Increased incidence of extreme high sea levels.
These changes will affect wildlife habitats dramatically, driving many species to extinction. Agricultural areas worldwide will also be impacted heavily, as is already the case in sub-Saharan Africa and other areas suffering from a shortened rainy season, too many heavy rains with erosion, and shrinking lakes.

Who is causing the problem?

The United States is the biggest contributor worldwide to greenhouse gases, which are responsible for trapping solar radiation and warming the planet. Carbon dioxide is the primary greenhouse gas and is, as we know, emitted when fossil fuels are burned. Americans contribute disproportionately more of this gas because our business-friendly federal government and most state governments place no limitations on CO2 emissions from industry. And because we drive big cars that burn a lot of fuel, with slack emission standards imposed by our oil-friendly federal government. The U.S. government continues to pretend that the connection between human activity and climate change is a theory rather than a fact. And the feds offer few incentives to Americans to reduce our fuel consumption at home or in vehicles.

Another report says the White House has stifled evidence of global warming

Two non-profit advocacy groups (the Union of Concerned Scientists and the Government Accountability Project) reported last Tuesday Jan 30 that dozens of federal scientists say they have been pressured to tone down their scientific findings related to climate change, to omit phrases like "global warming" and "climate change" from their reports, and have actually had their findings changed by government officials. Rep. Henry Waxman D-Calif said "it appears there may have been an orchestrated campaign to mislead the public about climate change."

Waxman said that House members have seen documents that "provide evidence that White House and agency officials repeatedly pushed to undermine the EPA's scientific conclusion about global warming."

Hmm. Americans generate more CO2 than any other country. President suppresses reporting about the consequences of our fossil fuel orgy. Well then. Perhaps it's time to take the reigns....


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