Until last week, government data on climate change indicated that the Earth has warmed over the last century, but that the warming slowed dramatically and even stopped at points over the last 17 years.
But a paper released May 28 by researchers at the National Oceanic and Atmospheric Administration has readjusted the data in a way that makes the reduction in warming disappear, indicating a steady increase in temperature instead. But the study’s readjusted data conflict with many other climate measurements, including data taken by satellites, and some climate scientists aren’t buying the new claim.
“While I’m sure this latest analysis from NOAA will be regarded as politically useful for the Obama administration, I don’t regard it as a particularly useful contribution to our scientific understanding of what is going on,” Judith Curry, a climate science professor at Georgia Tech, wrote in a response to the study.
And in an interview, Curry told FoxNews.com that that the adjusted data doesn’t match other independent measures of temperature.
“The new NOAA dataset disagrees with a UK dataset, which is generally regarded as the gold standard for global sea surface temperature datasets,” she said. ;“The new dataset also disagrees with ARGO buoys and satellite analyses.”
The NOAA paper, produced by a team of researchers led by Tom Karl, director of the agency’s National Climatic Data Center, found most of its new warming trend by adjusting past measurements of sea temperatures.
Global ocean temperatures are estimated both by thousands of commercial ships, which record the temperature of the water entering their engines, and by thousands of buoys – floatation devices that sit in the water for years.
The buoys tend to get cooler temperature readings than the ships, likely because ships’ engines warm the water. Meanwhile, in recent years, buoys have become increasingly common. The result, Karl says, is that even if the world’s oceans are warming, the unadjusted data may show it not to be warming because more and more buoys are being used instead of ships. So Karl’s team adjusted the buoy data to make them line up with the ship data. They also double-checked their work by making sure that the readjusted buoy readings matched ships’ recordings of nighttime air temperatures.
The paper came out last week, and there has not been time for skeptical scientists to independently check the adjustments, but some are questioning it because of how much the adjusted data vary from other independent measurements.
First, it disagrees with the readings of more than 3,000 “ARGO buoys,” which are specifically designed to float around the ocean and measure temperature. Some scientists view their data as the most reliable.
The ARGO buoy data do not show much warming in surface temperature since they were introduced in 2003. But Karl’s team left them out of their analysis, saying that they have multiple issues, including lack of measurements near the Arctic.
In an email, Karl told FoxNews.com that the ARGO buoy readings may be added to his data “if scientific methods can be found to line up these two types of temperatures together … (of course after correcting the systematic offsets) … This is part of the cumulative and progressive scientific process.”
Karl’s study also clashes with satellite measurements. Since 1979, NOAA satellites have estimated the temperature of Earth’s atmosphere. They show almost no warming in recent years and closely match the surface data before Karl’s adjustments.
The satellite data is compiled by two separate sets of researchers, whose results match each other closely. One team that compiles the data includes Climate Professors John Christy and Roy Spencer at the University of Alabama in Huntsville, both of whom question Karl’s adjusted data.
“The study is one more example that you can get any answer you want when the thermometer data errors are larger than the global warming signal you are looking for,” Spencer told FoxNews.com.
“We believe the satellite measurements since 1979 provide a more robust measure of global temperatures, and both satellite research groups see virtually the same pause in global temperatures for the last 18 years,” he said.
Karl said satellite data also have issues, including “orbital decay, diurnal sampling, instrument calibration target temperatures and more.”
Spencer said he agreed that those are issues, but they are less problematic than using data from thousands of ships and buoys. He added that there are a couple of satellites monitoring temperature at any given time, and that they are used to check each other.
Skeptics say there are yet more measurements, including those coming from balloon data, that line up with existing data more than with Karl’s newly adjusted data. They also note that even with Karl’s adjustments, the warming trend he finds over the last 17 years is below what U.N. models had predicted.
Some climate scientists applaud Karl’s adjustments and say they debunk the idea that the Earth has stopped warming.
“[This] points out just how small and fragile a notion that was,” Peter Frumhoff, director of science & policy at the Union of Concerned Scientists, told FoxNews.com
Asked about the contradiction with satellite data, he said he trusted the new paper.
“I trust the process of legitimate scientific peer review that this paper has undergone, as well as the care that its authors bring to their respected work,” he said, adding that, “the faux debate over a so-called ‘hiatus’ has been an unfortunate diversion from meaningful dialogue about how best to address the broadly recognized serious problem of climate change.”
But skeptics say Karl’s adjusted data is the outlier that conflicts with everything else. “Color me ‘unconvinced’,” Curry wrote.
Maxim Lott can be reached at www.maximlott.comor at firstname.lastname@example.org