Guest essay by Jim Steele, Director emeritus Sierra Nevada Field Campus, San Francisco State University
An Illusion of Extreme Climate Disruption
“While clearing larvae were starving in response to destruction of their hosts, survival in the outcrop was higher than previously recorded: an estimated 80% of larval groups survived.” 1 – C. D. Thomas, University of Leeds, United Kingdom
In Part 1, I documented how Camille Parmesan’s 1996 paper (heralded as proof that global warming was forcing butterflies northward and upward) had misread landscape change for climate change, how she failed to publish that “extinct” populations had now recovered and refused to provide the data to permit replication of her iconic paper. In Part 2, I documented how Parmesan hijacked the conservation success story of the Large Blue and the detailed conservation science of Jeremy Thomas in order to again blame global warming for expanding the range of endangered UK butterflies. In Part 3, I document how Parmesan kept half the evidence “off the books” to suggest extreme weather, supposedly caused by rising CO2, was causing population extinctions in the Sierra Nevada, and our top climate scientists then embraced and spread that myth.
In her paper Impacts of Extreme Weather and Climate on Terrestrial Biota2 Parmesan wrote, “Here, evidence is brought forward that extreme weather events can be implicated as mechanistic drivers of broad ecological responses to climatic trends. They are, therefore, essential to include in predictive biological models, such as doubled CO2 scenarios.” To demonstrate the destructive power of extreme weather, Parmesan and company detailed a sequence of events that caused the extinction of a Sierra Nevada population of Edith’s checkerspot butterfly. However unlike Parmesan’s 1996 paper,3 it was no longer global warming at low elevations that caused the population’s extinction. She now blamed climate change for unusually cold weather at higher elevations. The authors wrote:
“Twenty years of studies at one site in the Sierra Nevada of California have implicated three extreme weather events in carving a pathway to extinction of a whole set of E. editha populations at 2400 m.
“The first catastrophe occurred in 1989 when low winter snowpack led to an early and unusually synchronous adult emergence in April (as compared to the usual June flight). So early, in fact, that flowers were not yet in bloom and most adults died from starvation. Just one year later another relatively light snowpack again caused adults to emerge early. Adult butterflies, adapted to summertime conditions of warmth and sun, suffered many deaths during a “normal” May snow-storm. Each of these events decreased the population size by an order of magnitude…
“The finale came but 2 years later in 1992 when (unusually low) temperatures of ‑5° C on June 16, without the insulating snowfall, killed an estimated 97% of the Collinsia (host) plants….The butterflies had already finished flying and left behind young caterpillars that were not killed directly but starved in the absence of hosts. As of the latest census (1999), these sites remained extinct.”
Parmesan and her colleagues argued that CO2 warming had triggered cold events, which disrupted the “synchrony” between the weather, the butterflies and their food plants. Unlike Jeremy Thomas who was seeking to save an endangered species, Camille Parmesan was not interested in the details required for successful conservation. She was looking to support her global warming theory admittedly “searching for a climate fingerprint rather than critiquing each study”.4 And she knowingly omitted contradictory details and failed to mention that the other half of her observed population had prospered during those same events.
I say that she knowingly omitted the details because her future husband, Mike Singer, and C.D. Thomas wrote the research papers from which Parmesan manufactured her extreme weather story;5,6 when written, Parmesan served as their field assistant. Although weather is involved in each and every wildlife boom or bust, her reported extinctions had everything to do with how land use had changed the butterflies’ “microclimates”.
Parmesan directed the reader’s attention to just one of two neighboring populations. Both populations were literally within a stone’s throw of each other and normally they would be considered two halves of the same population equally affected by global warming. Yet only one half went extinct while simultaneously the other “natural” half survived. In fact by all accounts, the natural half didn’t just survive the “extreme weather”, it thrived!
In the early 1960s, only the “natural” half ever existed. As far as we know, it had always inhabited the rocky outcrops where the Sierra Nevada’s thin, glaciated soils prevented dense forest growth and permitted sufficient sunny patches for the caterpillars to warm their bodies. In contrast, the extinct population had just recently colonized habitat created in the 1960s after the US Forest Service had expanded logging into higher elevations. The logging opened the canopy to the warmth of the sun and created new microclimates.
Parmesan’s extinction story was a very selective retelling of the referenced study, “Catastrophic Extinction of Population Sources in a Butterfly Metapopulation”6 and a second companion paper.5 The caterpillars of the surviving natural population had fed mostly on a hardy perennial plant, which easily survives the Sierra Nevada’s erratic weather. The half-population that went extinct uncharacteristically fed on a fragile annual species Collinsia torreyi that typically invades logged areas. The checkerspot in the Sierra Nevada rarely laid its eggs on Collinsia, because normally it was not a reliable food source.
But recent logging near their natural habitat changed all that. Not only did logging open the forest floor to more sunlight, it also exposed deeper soils that had been enriched from the logging debris and burn-piles. That human disturbance created the just-right conditions for the annual Collinsia to survive for much longer periods. Serendipitously it also created a novel butterfly-plant synchrony. A longer-lived and more abundant Collinsia could now sustain the full development of hungry caterpillars.
With the life cycles of Collinsia and the checkerspot temporarily in synchrony, Collinsia suddenly became a valuable food resource. The butterflies from the outcrops opportunistically colonized the logged area and created the new second population. However this serendipitous food supply had simply prompted a boom and bust, not unlike the nearby ghost towns during the Sierra Nevada gold rush days.
While Parmesan indicted climate change in “the grand finale” during which frost killed 99.9% of the annual Collinsia, she omitted the crucial detail that the frost had little effect on the perennial food plants that sustained the natural population. More importantly, Parmesan also omitted that she had observed survival for the natural population “was higher than previously recorded, an estimated 80% of larval groups survived”.5,6
The deadly logged landscape had altered the microclimate and thus the timing of the caterpillars’ emergence from diapause. (Diapause is a period of inactivity and reduced metabolism similar to hibernation) In the Sierra Nevada, the checkerspot caterpillars diapause throughout the winter, snuggled safely under the soil and surface debris. Over the millennia, the caterpillar has evolved an instinctual sensitivity to the critical weather cues that triggered the safest time to emerge from their subsurface retreat. However, logging had opened the forest canopy, changing the pattern of snowfall accumulation, snow melt and forest-floor vegetation. Just as one centimeter of taller grass had cooled the subsurface for the Large Blue’s ant hosts, the recently logged forest floor was also heated differently. That sent the wrong signal to the diapausing caterpillars. Extreme weather affects adjacent locations equally; however, it is the different microclimates that determine how the animals respond.
Parmesan never told her readers that the natural population thrived or that the natural population maintained their synchrony with both the weather and their food plants. By re-constructing only half of the details, and with the apparent blessings of Dr. C.D. Thomas and her husband Dr. Singer, Parmesan metamorphosed a story of nature’s adaptability and resilience into another story of climate catastrophe. Such blatant sins of omission are a very serious offense, and this “scientific” paper should be retracted. The peer review process failed to detect an obvious distortion of the truth that was readily noticed by anyone who read the original study. To date, a modest 243 papers have cited her paper2 as another consensus evidence of catastrophic climate change caused by extreme weather. However when our leading climate scientists uncritically embraced her story, it was referenced by thousands more. 8
Seeking Extreme Weather and Biological Calamities
“overall in the United States there is a slight downward trend in the number of these extremes despite an overall warming in the mean temperature, but with cooling in the southeastern United States” 8
“The number of deaths related to tornadoes, hurricanes, and severe storms have either decreased or remained unchanged over the past 20 years.” 8 -Dr. David Easterling, National Oceanic and Atmospheric Administration
D.R. Easterling from the National Oceanic and Atmospheric Administration (NOAA), Thomas Karl, now the director of National Climatic Data Center and G.A. Meehl, the Senior Scientist at the National Center for Atmospheric Research were advocates looking to support CO2-caused warming. In their 2000 paper Climate Extremes: Observations, Modeling and Impacts, Easterling et al. wrote,
“if there are indeed identifiable trends in extreme climatic events it would add to the body of evidence that there is a discernible human affect on the climate.”
Apparently feeling a need to promote a greater sense of urgency, Easterling, Meehl, and Karl uncritically embraced any research that linked rising CO2 levels with extreme climate events and biological tragedy, and to that end they had invited Parmesan to coauthor their paper.
To raise our concerns about climate extremes, the first few paragraphs of Easterling’s paper listed the death and destruction caused by recent hurricanes and asked if the extreme events were natural or caused by humans. However they then reported that through the 1990s damage from extreme events had actually declined reporting, “The number of deaths related to tornadoes, hurricanes, and severe storms have either decreased or remained unchanged over the past 20 years.” 8
Heat stress was also declining; they reported that the number of days with extreme temperatures over 90.5°F and over the 90th percentile threshold peaked during the droughts of the 1930s and 1950s. They concluded, “Thus, overall in the United States there is a slight downward trend in the number of these extremes despite an overall warming in the mean temperature, but with cooling in the southeastern United States(emphasis added).”8 In an earlier paper Easterling also reported that maximums had not increased in Russia and China.9
A 2013 State of Knowledge Paper paper by 27 climate scientist has confirmed that for the contiguous USA, heat waves and droughts are still less common than in the 1930s and 50s as their graphs below depict. Although the authors offered mixed interpretations and caveats, the data was clear and they wrote, “For the conterminous United States (Fig. 1) the highest number of heat waves occurred in the 1930s, with the fewest in the 1960s. The 2001-10 decade was the second highest but well below the 1930s”
Easterling and Parmesan’s paper had also reported, “Examination of drought over the 20th century in the United States shows considerable variability, the droughts of the 1930s and 1950s dominating any long-term trend. Recent investigation of longer term U.S. Great Plains drought variability over the past 2000 years with the use of paleo-climatic data suggests that no droughts as intense as those of the 1930s have occurred since the 1700s. However, before the 16th century some droughts appear to have occurred that were of greater spatial and temporal intensity than any of the 20th-century U.S. droughts.”8
Similarly the 2013 State of Knowledge paper wrote, “each decade has experienced drought episodes that covered 30% or more (by area) of the contiguous United States. The 1930s and 1950s had the worst droughts, with 31.7% and 15.6%, respectively, of the U.S. experiencing their driest period on record. By comparison, during the first decade of the twenty-first century (2001-10) 12.8% and for 2011 8.3% of the U.S. experienced their record drought.” (see their graph below)
As shown in the graph below from 2013 State of Knowledge paper, mega-droughts far worse than the 30s and 50s happened over a thousand years ago based on reconstructed from tree ring data from 800 to 2000 AD.
Twenty-seven climate scientists concluded “decadal variations in the number of U.S. heat and cold waves do not correlate that closely with the warming observed over the United States. The drought years of the 1930s had the most heat waves, while the 1980s had the highest number of cold waves.”7
Although the data from both papers clearly showed no unusual increase in extreme weather, we must still be cautious about interpreting any extreme weather data. As Easterling lamented, “lack of long-term climate data suitable for analysis of extremes is the single biggest obstacle to quantifying whether extreme events have changed over the 20th century.”8 And he confessed that great caution needs to be taken when comparing extreme weather events warning, “investigators have often used quite different criteria to define an extreme climate event. This lack of consensus on the definition of extreme events, coupled with other problems, such as a lack of suitable homogeneous data for many parts of the world, likely means that it will be difficult, if not impossible, to say that extreme events in general have changed in the observed record (emphasis added).”8
Yet despite the lack of any evidence of unusually extreme weather and the lack of reliable data, Easterlng and Parmesan’s paper ironically marked the beginning of an era in which every weather event would soon be translated into “unprecedented extremes” caused by CO2 climate change, and again Parmesan’s butterfly effect was again instrumental in promoting biological doom.
With scant evidence that climate change had caused any increase in extreme weather they emphasized Parmesan’s extinctions writing, “Several apparently gradual biological changes are linked to responses to extreme weather and climate events.” They repeated Parmesan’s earlier fairly tale that climate change was forcing butterflies northward and upward, even adding imaginary data, “In western North America, Edith’s Checkerspot butterfly has shifted its range northward (by 92 km) and upward (by 124 m) during this century.” Did Parmesan not tell our top climate scientists that there was never any such migration? Yet they continued “drought, “false springs,” and midsummer frost, have been directly observed to cause extinction of local populations of this butterfly. Thus, the gradual northward and upward movement of the species’ range since 1904 is likely due to the effects of a few extreme weather events on population extinction rates.”
Did Parmesan also not tell them the natural populations in unlogged habitat had experienced their greatest survival during her purported “extreme weather” event? Did Easterling, Karl and Meehl not know Parmesan’s paper kept half the evidence off the books? Or did their CO2 advocacy turn a blind eye to bad science? Despite no increase extreme weather and no real biological catastrophe, the paper Climate Extremes: Observations, Modeling and Impacts is cited by over 1,650 papers to build a consensus and the public is bombarded with fear mongering that we should “Be Very Afraid”. What I fear most is how the politics of climate change has defiled good science and good environmental science!
Adapted from the chapter Deceptive Extremes in Landscapes & Cycles: An Environmentalist’s Journey to Climate Skepticism by Jim Steele
The book is also available on Amazon here
1. Singer, M., and C. D. Thomas (1996) Evolutionary responses of a butterfly metapopulation to human and climate-caused environmental variation. American Naturalist, vol. 148, p. S9–S39.
2. Parmesan, C., et al. (2000) Impacts of Extreme Weather and Climate on Terrestrial Biota. Bulletin of the American Meteorological Society, vol. 81, 443‑451
3. Parmesan, C., (1996) Climate and Species Range. Nature, vol. 382, 765-766
4. Parmesan, C. and Yohe, G. (2003) A globally coherent fingerprint of climate change impacts across natural systems. Nature, vol. 142, p.37-42.
5. Thomas, C.D, et al., (2000) Ecological and evolutionary processes at expanding range margins. Nature, vol. 411, p. 577‑581.
6. Thomas, C.D. et al. (1996) Catastrophic extinction of population sources in a butterfly metapopulation. American Naturalist, vol. 148, p. 957–975
7. Peterson, T., et al. (2013) Monitoring and Understanding Changes in Heat waves, Cold Waves, Floods and Droughts in the United States, State of Knowledge. Bulletin of the American Meterological Society. June 2013, p. 821-834.
8. Easterling, D.R., et al. (2000) Climate extremes: Observations, modeling, and impacts. Science, 289
9. Easterling, D., et al. (2000) Observed Variability and Trends in Extreme Climate Events: A Brief Review. Bulletin of the American Meteorological Society, vol. 81, p. 417-425