NASA Data Exaggerated U.S. Warming

Published October 1, 2007

U.S. temperature data compiled and reported by NASA since 2000 contained errors that caused the organization to falsely claim a number of recent years were the hottest or among the hottest on record, scientists have discovered.

High-Profile Scare Stories

During recent years, the early January news cycle has been dominated by high-profile stories claiming U.S. temperatures during the preceding year ranked at or near the top of the warmest years on record.

The Washington Post, for example, published a front-page article on January 10, 2007 titled “Climate Experts Worry as 2006 is Hottest Year on Record in U.S.” The article began, “Last year was the warmest in the continental United States in the past 112 years–capping a nine-year warming streak ‘unprecedented in the historical record.'”

The Associated Press, USA Today, and other media outlets published similar stories. A January 9, 2007 news release from the Union of Concerned Scientists argued, “No one should be surprised that 2006 is the hottest year on record for the U.S.”

NASA Admits Errors

However, climate expert Steve McIntyre–one of the “deniers” alarmists claim should be ignored in the ongoing global warming debate–noticed irregularities in the U.S. temperature data compiled since 2000.

A thorough review of the raw data revealed that beginning in 2000 NASA applied a new formula to its methods of smoothing out and averaging raw temperature data. The new formula, McIntyre proved, resulted in NASA unjustifiably adding 0.15ยบ Celsius to each year’s final temperature average.

Confronted with McIntyre’s findings, NASA admitted its error and quietly revised downward its post-2000 U.S. temperature reports.

Media Strangely Silent

As a result, scientists discovered 2006 was not the warmest year in U.S. history. In fact, 1934 was the warmest year, and 2006 fell to a distant fourth. Only four of the top 11 warmest years have occurred since 1954, according to the corrected data.

Although the mainstream media had annually given high-profile coverage to the erroneous reports of record-setting U.S. temperatures, few mainstream newspapers or news networks reported the corrected data, even in the briefest of mentions.

‘Denier’ Vindicated Again

“This is precisely how the ‘hockey stick’ purporting to rewrite history–erasing the Medieval Warm Period and subsequent Little Ice Age–was debunked, and indeed by the very same person–McIntyre,” said Chris Horner, a senior fellow at the Competitive Enterprise Institute.

“While the hockey stick error was glaring, as it absurdly rewrote well-established history, this new documentation of data errors overstating recent warming was pure investigative genius fueled by dogged determination,” Horner added. “McIntyre knew that our surface measuring stations are suspect. Some were exposed as being in asphalt parking lots, on tar roofs, next to air conditioning vents, attached to a chimney, and overhanging a Weber Grill. So he began digging and found an otherwise inexplicable jump in the year 2000.”

Similarly, in the current instance, “Again, a Gore advisor–James Hansen this time–refused to provide his codes, but again McIntyre was able to recreate enough to present his findings to NASA, who corrected the error. The alarmists who trumpeted recent years as ‘warmest ever!!!’ in the United States (by a mere tenth of a degree) now dismiss this reversal–2000 and subsequent years being cooler than 1900–as just being a tenth of a degree or so. Well, either that’s a big deal whichever direction it falls or it isn’t. Which time are you lying?” Horner asked.

Full Data Disclosure Necessary

“The key lesson here is not that NASA, GISS [the Goddard Institute for Space Studies], Jim Hansen, or anyone else was intentionally making mistakes, but that in complex data compilations and analyses, no matter how diligent you try to be, mistakes work their way in,” said Robert Ferguson, president of the Science and Public Policy Institute.

“This is why it is important to be as open as possible as a scientist about what you did and how you did it, to make full disclosure of all your data and methods,” Ferguson explained. “This allows others to replicate your work and helps ensure that science moves forward on the best possible footing, and that policymakers operate off of factual data and not belief systems.

“It is for this reason that it is of the gravest concern that leading climate scientists and organizations, up to and including even the IPCC [Intergovernmental Panel on Climate Change], are still failing to make full disclosure regarding many of the data that they spin into the public domain,” Ferguson observed.

James M. Taylor ([email protected]) is managing editor of Environment & Climate News and a senior fellow at The Heartland Institute.

For more information …

Steve McIntyre, Climate Audit:

Joe D’Aleo, revised temperature data: