Expert witnesses called by Sen. Barbara Boxer to testify during Senate Environment and Public Works hearings contradicted a key assertion made by President Barack Obama on climate change.
‘No Patience’ for Dissent
Speaking at a Democratic fundraiser less than a month before directing the U.S. Environmental Protection Agency to impose costly new restrictions on carbon dioxide emissions, Obama said, “We also know that the climate is warming faster than anybody anticipated five or 10 years ago.”
“I don’t have much patience for people who deny climate change,” Obama added.
Boxer’s Expert Witnesses Dissent
During the July 18 Senate Environment and Public Works hearings, Sen. David Vitter asked a panel of experts, including experts selected by California Democrat Boxer, “Can any witnesses say they agree with Obama’s statement that warming has accelerated during the past 10 years?”
For several seconds, nobody said a word. After the period of deafening silence, Weather Channel meteorologist and global warming activist Heidi Cullen attempted to change the subject, saying our focus should be on longer time periods rather than the 10-year period mentioned by Obama. When pressed, however, she contradicted Obama’s central assertion and said warming has slowed, not accelerated.
Several minutes later, Sen. Jeff Sessions (R-AL) returned to the topic and sought further clarity. Sessions recited Obama’s quote claiming accelerating global warming during the past 10 years and asked, “Do any of you support that quote?”
Again, a prolonged and deafening silence ensued. Neither Cullen nor any of the other experts on the panel spoke a word, not even in an attempt to change the subject.
Sessions Debunks Cullen’s Claims
Cullen added to Boxer and Obama’s embarrassment by making demonstrably false or misleading statements as focal points of her testimony.
Cullen claimed global warming is causing an increase in wildfires. However, Sessions presented a chart showing the number of U.S. wildfires is in long-term decline. Although the number of total acres burned may have increased, that is due to a recent change in government fire policy that no longer aims to extinguish fires immediately after they begin.
Cullen also claimed global warming is causing more extreme heat, but Sessions presented a chart showing no increase in daily high temperature records. U.S. daily high temperature records were set much more frequently during the first half of the 20th century, Sessions’ chart showed.
Cullen claimed global warming is causing more drought, yet Sessions presented a chart showing no long-term increase in drought in the United States. Globally, scientific data and peer-reviewed studies show a long-term increase in global soil moisture, resulting in less frequent and less severe drought.
Cullen claimed global warming is causing a decrease in snow coverage. However, Rutgers University Global Snow Lab data over the past 45 years show Northern Hemisphere snow extent is experiencing long-term increase, not decrease.
Cullen finally claimed global warming was a major factor producing Hurricane Sandy and its negative impacts. However, Sessions presented a chart showing there has been no long-term increase in hurricanes. Indeed, the U.S. Northeast experienced much more hurricane activity during the first half of the 20th century, when human carbon dioxide emissions were relatively minor, than in the 60-plus years since.
Pielke Addresses Extreme Weather
Roger Pielke, Jr., professor of environmental sciences at the University of Colorado, added weight to Sessions’ data and charts, testifying that global warming is not causing more frequent and severe weather events.
Pielke, who agrees that humans are causing some global warming, testified it is important not to exaggerate the impacts of global warming. Pielke debunked Cullen’s extreme-weather claims and additionally debunked Reinsurance Association of America president Frank Nutter’s testimony that global warming is causing more insurance losses. Pielke pointed out the increase in insurance losses resulting from extreme weather events is due to more wealth created and at risk to normal weather events.
“Globally, weather-related losses have not increased since 1990 as a proportion of GDP [gross domestic product],” Pielke testified.
Pielke noted weather-related losses have declined approximately 25 percent since 1990.
Spencer Explains Minimal Warming
Roy Spencer, principal research scientist at the University of Alabama in Huntsville and U.S. Science Team Leader for the NASA satellite instruments measuring global temperature, pointed out global temperatures are rising much more slowly than predicted by United Nations computer models. Spencer charted tropical mid-troposphere temperature predictions of 73 climate models and showed all 73 predicted more warming than actually occurred.
Tropical mid-troposphere temperatures are especially important because this is where human-caused global warming is expected to leave its most visible fingerprint.
Spencer also showed global warming throughout the planet has occurred at only half the pace predicted by UN computer models.
Applying real-world observations to climate model predictions, Spencer demonstrated a doubling of atmospheric carbon dioxide would cause only about 1.3 degrees Celsius of global warming. This modest amount of global warming would not create a global warming crisis, Spencer noted.
Boxer’s Hearings Backfire
Boxer likely envisioned her high-profile global warming hearings as an opportunity to build momentum for congressional or EPA action to restrict carbon dioxide emissions. Instead, her witnesses made claims that were easily debunked by real-world scientific evidence. At the same time, Boxer gave scientists such as Pielke and Spencer a visible platform to explain why humans are not causing a global warming crisis.
James M. Taylor ([email protected]) is managing editor of Environment & Climate News.