Climatologist John Christy says the occurrence of both record-high and record-low temperatures is declining, contrary to Seth Borenstein's claims. (Photo: mantaphoto/Getty Images)
By Marc Morano, Daily Signal,
Associated Press reporter Seth Borenstein has made another attempt to convince the public of global warming, but his latest analysis has climate scientists once again refuting his claims.
On Tuesday, Borenstein cited AP analysis that found hot temperature records in the U.S. were being broken twice as often as cold temperature records. He concluded that this is “a clear sign of human-caused climate change.”
The AP looked at 424 weather stations throughout the Lower 48 states that had consistent temperature records since 1920 and counted how many times daily hot temperature records were tied or broken and how many daily cold records were set. In a stable climate, the numbers should be roughly equal. Since 1999, the ratio has been two warm records set or broken for every cold one. In 16 of the last 20 years, there have been more daily high-temperature records than low.
He went on to cite various climate scientists:
The AP shared the data analysis with several climate and data scientists, who all said the conclusion was correct, consistent with scientific peer-reviewed literature and showed a clear sign of human-caused climate change. They pointed out that trends over decades are more robust than over single years.
The analysis stopped with data through 2018. However, the first two months of 2019 are showing twice as many cold records than hot ones.
But the scientists he cited don’t speak for all climate scientists. Some, in fact, are dismissing his “clear sign” analysis.
Climatologist John Christy told me that Borenstein framed the data wrongly:
The occurrence of both record highs and record lows is declining. Record-low events are simply declining more rapidly than record highs. The drop in record lows is associated with development around the weather stations, which causes low temperatures to increase more than highs for a variety of reasons.
Most climate change activists cite the greenhouse gas theory—that man-made gases are causing changes to the Earth’s temperature. Christy noted that this theory predicts an increase in frequency of record-breaking temperatures. Yet the exact opposite is happening in the U.S.—the frequency of those temps is declining.
The cause? Christy says it’s likely “urbanization and natural variability.”
He added: “I’ve actually done this same analysis for the 682 [U.S. Historical Climatology Network] stations with at least 105 years of record since 1895. It is clear that the occurrence of both record high and record lows has declined since 1895, thanks to many records set from the 1920s to 1954.”
The AP … is spinning the story by only noting that record lows are fewer than highs now—but the real story is that in the U.S., both extremes are falling. This is consistent with the decline in number of days greater than 100 [degrees] Fahrenheit (or 105 Fahrenheit or 95 Fahrenheit, etc.). The differential decline in record temps is inconsistent with [greenhouse gas] theory, which predicts an increase in record highs and higher TMax in general.
Climatologist Roger Pielke Sr. expressed skepticism of the AP analysis as well:
Without assessing the role of increased urbanization and other land-use changes … changes in atmospheric aerosols overhead, microclimate around observing site, changes in heights of observations, and concurrent trends in surface air humidity, it is not robust to attribute any changes in extreme temperatures to just human-added atmospheric CO2.
He added: “We have published on each of these subjects but work remains mostly ignored.”
Borenstein’s claims are also countered in the peer-review scientific literature. A 2018 analysis found that multiple recent studies and long-term data refuted claims that there had been an increase in heat waves. In addition, a 2013 paper published in the Journal of Applied Meteorology and Climatology found that U.S. extreme heat waves have decreased since the 1930s.
It’s also important to note that recent temperatures are not at all unusual, with 2018 continuing a several-year cooling trend. The media-hyped “hottest year” claims do not hold up to scrutiny. Princeton physicist Will Happer ridiculed such claims and explained that “alleged record warmings are tenths of a degree or less, comparable to the statistical error.”
Borenstein, the chief climate reporter for the Associated Press, has a long history of promoting dubious climate claims and essentially lobbying the public to “believe” that man-made climate change is a dire emergency and that government “solutions” are needed.