This week marks 20 years since NASA’s James E. Hansen testified before a joint Congressional hearing that there was a strong “cause and effect” relationship between “current” climate conditions and emissions of carbon dioxide into the atmosphere. Current conditions in 1988 were a big heat wave and drought in the eastern U.S. The public bit. Two days later, 70 percent of the respondents to a CNN poll agreed with the proposition that 1988’s misery was caused by global warming. Yet in fact, no climate scientist can ever blame an individual weather event, like a heat wave or drought, on global warming.
Hansen’s testimony that year included a graph of annual temperatures, with a dramatic spike on the last point, the January-May temperatures. He knew, as does any scientist, that a sample of monthly data will vary much more than year-to-year temperatures, and that monthly data could give a false impression of extremely hot (or cold) conditions, compared to annual temperatures.
Hansen has long employed stagecraft
for political gain. On June 23, 1988, he delivered his testimony in an unusually toasty hearing room. Why was it so warm? As then-Sen. Tim Wirth (D., Colo.), told ABC’s Frontline
: “We went in the night before and opened all the windows, I will admit, right, so that the air conditioning wasn’t working inside the room . . . it was really hot.”
Hansen offered three scenarios for future warming. “Scenario A,” was business as usual, meaning carbon dioxide emissions would continue with no stringent curbs. It forecast an ever-increasing rate of emissions, but the rate of increase turned out to be constant. So this scenario predicted too much warming. Indeed, even though there was no major curb on emissions, they still didn’t increase exponentially.
“Scenario B,” which forecast a slower increase, is pretty close to what has happened, as far as global carbon dioxide emissions go. It projected that increasing CO2 concentrations would result in global temperatures about 1.48°F above the 1951-80 average in 2007. But that’s 33 percent more warming than has actually been observed, according to data published by the U.N. Intergovernmental Panel on Climate Change.
“Scenario C” stopped the growth of carbon dioxide emissions altogether in 2000, which obviously hasn’t happened.
Every climate scientist knows there’s been no — zero — net change in surface temperatures in the last ten years, as shown in the climate history of the United Nations Intergovernmental Panel on Climate Change.
Unless you throw in a volcano (there hasn’t been a decent one in the last decade), none of Hansen’s valid 1988 models predict what’s actually happened. He simply predicted too much warming, especially for the last ten years. Why should we believe what he forecasts for the rest of the 21st century?
Hansen’s 1988 predictions were flatly wrong about the extent of global warming. Yet on the 20th anniversary of his original testimony, Hansen said that people “should be tried for high crimes against humanity and nature” for spreading doubts about the promised global warming holocaust. He named names, too: the CEOs of ExxonMobil and Peabody Energy.
Excuse me, Inquisitor Hansen, but what exactly are their crimes against humanity? Being demonstrably wrong about climate science?