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Projections.

Gore says, “Here’s where CO2 is now [roughly 380 ppm]—way above anything measured in the prior 650,000-year record. And within 45 years, this is where the CO2 levels will be [roughly 620 ppm] if we do not make dramatic changes quickly.”

Since 1977, CO2 levels have been increasing at 1.5 ppm per year, less than half of what Gore predicts.

"A spike in the amount of carbon dioxide released into the atmosphere between 2001 and 2003 appears to be a temporary phenomenon ..." The spike of about 5 ppm was added to the atmosphere between 2001 and 2003.  Since then the rate has returned to the long term trend of about 1.5 ppm.

See National Oceanic and Atmospheric Administration, “After Two Large Gains, Rate of Atmospheric CO2 Increase Returns to Average,” NOAA Reports, March 31, 2005,

There has been no significant increase or decrease in the annual CO2 growth rates over the past 30 years.  So there is no accelerating trend.  If this trend continues, by the year 2050, the atmospheric CO2 levels will be below nearly all of the projections made by the Intergovernmental Panel on Climate Change (IPCC) in the 2001 Third Assessment Report.  Consequently, the temperature rise, over the same period, will also likely be at or below the lowest IPCC forecast. [This paragraph will be updated based on the IPCC 2005 report when the data is available]

See Keeling, C. D., and T. P. Whorf, “Atmospheric CO2 Records from Sites in the SIO Air Sampling Network, Trends: A Compendium of Data on Global Change (Oak Ridge, TN: Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, 2005).

and  “Ups and Downs: Redux,” World Climate Report, March 31, 2005.

The CO2 warming effect is not linear as Gore implies. It is logarithmic which means that the warming effect of increasing CO2 becomes much less as CO2  continues to increase.

See Intergovernmental Panel on Climate Change., Climate Change 2001: The Scientific Basis, Table 6.2, p. 358.

There has been no increase in the rate of warming since 1970. For the past 30 years, the planet has warmed at a fairly constant rate of 0.17°C per decade. The year 2005 reported to be the second warmest year in (the instrumental) record – it was still in line with the 0.17ºC per decade.

See Phil Jones and Mike Salmon, “Climatic Research Unit: Data—Temperature,” August 2006

and Patrick Michaels, “Hot Tip: Post Misses the Point!” World Climate Report, January 31, 2006

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