The Daily Caller's Bad Science on 'Global Cooling'
"It is a favorite tactic of those who resist climate regulation to cherry-pick data from limited time periods and limited geographical areas to draw broad conclusions that are contrary to the overwhelming body of climate science," says Michael Gerrard, a law professor and director of the Sabin Center for Climate Change Law at Columbia University. JIM URQUHAR/REUTERS
The Daily Caller published a story on Tuesday that posits that federal data shows the U.S. climate is actually cooling, not warming up, and thus debunking this whole man-made global warming thing that the pope seems really up in arms about. There’s even a graph to prove it.
Except it’s totally wrong.
The article, headlined “America’s Most Advanced Climate Station Data Shows U.S. in a 10-Year Cooling Trend,” is a great example of the ways climate data can be used to fabricate an argument that opposes the scientific consensus on climate change and of the data itself.
First of all, the data does not show a cooling trend. Second of all, even if it did (which it doesn’t!), it wouldn’t be proof that the globe is indeed in a global warming “pause,” which is the secondary argument of the article.
Let’s break it down.
The author quotes Anthony Watts, a former meteorologist who runs a blog dedicated to climate change denial. For the graphs on which The Daily Caller article focuses, Watts used monthly temperature data from the U.S. Climate Reference Network (USCRN) from 2005 to 2015. The USCRN is a system of temperature monitoring stations around the country, managed by the National Oceanic and Atmospheric Administration (NOAA). Watts plotted the average temperature data from those stations over 10 years on a graph and found an almost-stable trend line that indicated slight cooling. This, he writes, “clearly” shows that a “‘pause’ or ‘hiatus’ exists in this most pristine climate data,” pointing to the much-referenced argument in “skeptic” circles that there has been a global warming “pause” in recent years.
There are two major problems here.
First, in 2005, the USCRN was far from complete. As of January 1, 2005, only 69 of its 114 temperature monitoring stations, or just 60 percent of the ultimate total, had been installed, according to NOAA’s Howard Diamond, who is the program manager of USCRN. The last and 114th station wasn’t installed until September 2008, which means that comparing the data from 2005 to 2008 with data after 2008 produces a severely lopsided analysis. This is especially important because of the geographic nature of temperature monitoring: Since only stations in certain areas of the U.S. were up and running before 2008, there is a lot of information missing from the averages of those early years.
If Watts had chosen to exclude the data from before the USCRN was complete and start his analysis on, say, January 1, 2009, to the present, he’d actually see see “a slightly increasing trend of temperature anomaly data in the contiguous U.S.,” according to Diamond, as shown in the graph below. “So the same upward trends in temperature data we have seen have been and continue to be the case.” In other words, the U.S. is still getting warmer.
A graph showing the trends in temperature anomalies monitored by USCRN from 2009 to 2015, layered over with data sets from two older climate monitoring networks, the U.S. Historical Climatology Network and U.S. Climate Divisional Dataset. The slight warming trend for this period is consistent across all three data sets. USCRN/NOAA
Second, The Daily Caller tried to extrapolate that interpretation of U.S. data to apply to global climate trends. The author quotes from Watt’s blog: “Clearly, a ‘pause’ or ‘hiatus’ exists in this most pristine climate data.” The piece goes on:
Watts’s plotting of [USCRN] data comes after NOAA researchers put out a study claiming there’s been no “hiatus” in global warming—a 15-year period with no significant rise in the world’s average temperature. Basically, NOAA made adjustments to weather stations, buoys and ships that increased the warming trend from older data.
The peer-reviewed NOAA study the author references (and which he previously referred to as “fiddling with data”) found “possible artifacts of data biases” in prior global average temperature analysis and set about to update the analysis. The results, the authors wrote, “do not support the notion of a 'slowdown' in the increase of global surface temperature.” Basically, they conclude that a “pause” doesn’t exist.
Even if one chooses to believe that the NOAA paper is all smoke and mirrors, you still can’t extrapolate U.S. data to apply to the whole globe; clearly, the surface area covered by the U.S. is just a fraction of the planet, and since temperature fluctuates substantially according to geography—well, you get the idea.
"It is a favorite tactic of those who resist climate regulation to cherry-pick data from limited time periods and limited geographical areas to draw broad conclusions that are contrary to the overwhelming body of climate science," says Michael Gerrard, a law professor and director of the Sabin Center for Climate Change Law at Columbia University.
But still, as it happens, if you were to draw the comparison properly, by beginning from 2009 when all the USCRN monitoring stations were installed, you wouldn’t be far off from the global trends, according to Diamond.
“The USCRN was designed to get a national signal of climate change,” Diamond explains, and not act as a global indicator. “But frankly, the upward trend we see in the U.S. is consistent with what other people are finding across the globe.”
Comments