WhatFinger


Another suite of articles in the mainstream media that appear to be littered with scientific flaws

Climate Science Journalism Problems in the Southwest



The hyperbole masquerading as objective and rigorous climate science journalism rolls on. As part of a three part series on "How climate change is altering the deserts of the southwest," Ian James states the following:
"In the deserts of the Southwest, adaptation will likely involve learning to live with more extreme heat. Scientists predict in the newly released National Climate Assessment report that annual average temperatures in the Southwest could rise by 5.5-9.5 degrees by the end of the century if emissions of greenhouse gases continue to grow. That would make the climate of cooler high-elevation deserts more like the region's hottest low-elevation deserts. Palm Springs, Indio and El Centro, among other places, could be scorched by average temperatures hotter than those seen today in Death Valley, which holds the record for the hottest temperature ever recorded: 134 degrees."
There hasn't been a significant trend in "annual average temperatures in the Southwest" since the late 1980s. Since the mid-1990s, the correlation has been negative -- not positive. Emissions of greenhouse gases have been increasing rapidly for the past quarter-century, and yet average temperatures in the Southwest exhibit no significant trend, and show a nearly significant declining trend since 2000.

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Perhaps this lack of correlation between greenhouse gas concentrations in the atmosphere and average annual temperatures in the Southwest for at least a couple decades should cause some doubt over projections that further increases in greenhouse gas emissions will lead to increases in the average annual temperature of between 5.5 to 9.5°F for the Southwest by 2100? The trend in annual average temperatures for this region since 1895 has been only +1.7°F/century. How realistic are projections of an additional 5.5 to 9.5°F of warming over the next 86 years, especially when there has been no significant trend since Reagan was president. What about the potential for Palm Springs to "be scorched by average temperatures hotter than those seen today in Death Valley, which holds the record for the hottest temperature ever recorded: 134 degrees"? The Desert Sun article claims that "climate data from weather stations across the Southwest show that average temperatures have risen during the past 20 years [since 1994] as compared to average temperatures before 1960." Maybe, but here is what the article doesn't tell you. Average summertime temperatures in Palm Springs during June, July, or August don't have a hint of a statistically significant trend since 1994. Actually, there is a statistically significant trend towards decreasing average August temperatures in Palm Springs over the past 20 years. Yes, a cooling -- not warming -- trend. Average annual temperatures are not increasing in Palm Springs over the past two decades, either. Monthly mean maximum temperatures during the summertime aren't increasing. In fact, there is a statistically significant decreasing trend for August "during the past 20 years." The same applies for the highest maximum temperatures during each of the summer months. No trends for the past two decades during June and July, and a significant declining trend in August. According to the National Parks Service, the average daily highs in Death Valley during June, July, and August are 110, 116, and 115°F, respectively. Over the past two decades, the corresponding average daily highs in Palm Springs were 104, 109, and 108°F with no increasing trends (actually, a decreasing trend in August). Average daily temperatures during June, July, and August in Death Valley are 96, 102, and 101°F. Compare that to the corresponding values of 88, 94, and 93°F for Palm Springs since 1994 -- with no increasing trends (and, once again, a decreasing trend in August). Odds of Palm Springs reaching that "hottest temperature ever recorded" of 134°F in the coming century? Effectively zero if trends since 1922 are any indication. Palm Springs has no significant trend in maximum temperatures since records began in the early 1920s. When discussing the Colorado River system, John Entsminger -- general manager of the Southern Nevada Water Authority -- states the following:
"'That's what climate change can mean for this basin, that you're going to see not only less precipitation but precipitation that doesn't get into the river and ultimately results in less water,' Entsminger said. 'All of us are going to have to come together and, in my opinion, in the 21st century figure out how to live with less water.'"
Less precipitation? I can find no significant trends in annual precipitation since 1895 (i.e., almost 120 years) for the areas comprising the Colorado River basin in California, Arizona, Nevada, Utah, New Mexico, Colorado, or Wyoming. More claims that need to be challenged:
"The average number of days each year with temperatures hotter than 90 degrees increased by more than 25 percent [in the Southwest]. And while the comparison of those periods showed only a slight decline in precipitation region-wide, some areas -- such as Indio, Blythe and Palm Springs -- have grown significantly drier ... Low-lying Indio has seen a sharp rise of about 2.5 degrees in average temperatures, as well as a drop in average annual rainfall from 3.1 inches to 1.8 inches."
I find no significant trend in annual precipitation at Palm Springs/Indio since records began in 1908. No significant trend at Blythe, either, since records began in 1949 -- indeed, the correlation is positive towards more precipitation, not less. As for the "number of days each year with temperatures hotter than 90 degrees," the San Diego, Los Angeles, Las Vegas, Phoenix, Yuma, Flagstaff, and Albuquerque climate regions all show no significant trends over at least the past 30 years. How is that consistent with the catastrophic anthropogenic global warming mechanism and a supposedly continuing warming trend at each location? Another problematic claim:
"Climate records show significant shifts already occurring across the region and in particular in areas near Joshua Tree National Park, which straddles the boundary between the higher Mojave Desert and the lower Sonoran Desert. During the past 20 years, the high desert town of Twentynine Palms has grown 1.4 degrees warmer on average and slightly drier than it was in the decades before 1960."
What nonsense. According the NOAA National Weather Service database, there has been absolutely no significant trend whatsoever in precipitation at Twentynine Palms since records began in 1936. The temperature record for this town over the past 30 years also looks to be far too incomplete for any reliable statistical analyses to be conducted. Only half of the years during the last three decades have complete monthly temperature records. There are serious scientific problems throughout this piece of so-called science journalism. Just read the following description of the methods used for the series:
"In order to analyze changes in climate in the Southwest, The Desert Sun used the National Climatic Data Center's online database and obtained monthly summaries for a selection of weather stations across much of the region. Thirty-one weather stations with some of the longest continuous records were chosen, with data on temperatures and precipitation starting between the 1890s and 1940s. The data were analyzed by converting monthly average temperatures, as well as average monthly highs and lows, into averages by decade. Temperatures and precipitation during the past 20 years, since 1994, were then compared with the averages in the decades before 1960 -- a time frame often used by scientists in studying climate change."
It doesn't appear as if any statistical tools whatsoever were used to determine if the trends and/or "differences" between time periods were statistically significant. Pure junk science. In addition, it sounds as though the average since 1994 was compared to "the averages in the decades before 1960," which could apparently mean any period from either the 1890s to 1960 or from the 1940s to 1960.

No consistent datum for comparison appears to be employed

In other words, no consistent datum for comparison appears to be employed. Instead, whatever record existed before 1960 was used in its entirety? So we could be comparing the 1994-current period with the 1940-1960 period at Station A, and the 1994-current period with the 1895-1960 period at Station B? Given the climatic cycles that exist in this region over time, such comparisons yield non-comparable trends. Overall, I either can't reproduce many of the findings from this media series on climate change in the Southwest, or have such serious concerns over the data analysis methods being used that the results of the study should be considered unreliable and thereby unsuitable for any serious policy discussions.


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Sierra Rayne -- Bio and Archives

Sierra Rayne holds a Ph.D. in Chemistry and writes regularly on environment, energy, and national security topics. He can be found on Twitter at @srayne_ca


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