Christy's Unconvincing Congressional Testimony
by dana1981, Skeptical Science, March 10, 2011
"In 1994, Nature magazine published a study of mine in which we estimated the underlying rate at which the world was warming by removing the impacts of volcanoes and El Niños (Christy & McNider 1994.)...The result of that study indicated the underlying trend for 1979-1993 was +0.09 °C/decade...I have repeated that study for this testimony with data which now cover 32 years...In an interesting result, the new underlying trend remains a modest +0.09 °C a decade for the global tropospheric temperature"
Should Have Seen More Warming?
"+0.09 °C/decade for the global tropospheric temperature...is still only one third of the average rate the climate models project for the current era (+0.26 °C/decade.)"
“The resulting trend of reconstructed tropospheric temperatures from satellite data is physically consistent with the observed surface temperature trend. For the tropics, the tropospheric warming is ~1.6 times the surface warming, as expected for a moist adiabatic lapse rate.”
"The observations at the surface and in the troposphere are consistent with climate model simulations...The resulting global averaged tropospheric trend is +0.20 K/10 yr"
"All the [satellite lower troposphere temperature] analyses except UAH are compatible with computer model projections of tropospheric warming; the error ranges include the values expected from model simulations."
Heating from Land Use Changes
"warming is dominated by increases in nighttime temperatures, with little change in daytime temperatures. This pattern of warming is a classic signature of surface development (land cover and land use change) by human activities."
"one of the clearest signatures or fingerprints of greenhouse gas warming as depicted in climate models...consists of a region of the tropical upper atmosphere which in models is shown to warm at least twice as fast as the surface rate of warming...We, and others, have tested this specific signature, i.e. this hypothesis, against several observational datasets and conclude that this pervasive result from climate models has not been detected in the real atmosphere."
"Spencer tracks large global temperature changes over periods of several weeks...he finds the real climate system is dominated by negative feedbacks (probably related to cloud variations) that work against changes in temperature once that temperature change has occurred."
"the IPCC and other similar Assessments do not represent for me a consensus of much more than the consensus of those who already agree with a particular consensus."
Impact of Carbon Regulations
"we calculate that the impact of legislative actions being considered on the global temperature is essentially imperceptible....downward adjustments to North American coal use will have virtually no effect on global CO2 emissions"
More Carbon is Better?
"...the many positive benefits of higher concentrations of CO2 in the atmosphere, especially for the biological world"
- The hot spot is an anthropogenic signature
- There's no consensus
- CO2 limits will make little difference
- More carbon is better