Guest post by David Middleton
From the formerly respectable National Geographic…
By Aaron Sidder
PUBLISHED JUNE 29, 2016
Adélie penguins (Pygoscelis adeliae) have survived in Antarctica for nearly 45,000 years, adapting to glacial expansions and sea ice fluctuations driven by millennia of climatic changes. The penguins remained resilient through these changes, but new research from the University of Delaware suggests that unique 21st-century climates may pose an existential threat to many of the colonies on the Antarctic continent.
Published Wednesday in Scientific Reports, the study, led by oceanographer Megan Cimino, found that up to 60 percent of the current Adélie penguin habitat in Antarctica could be unfit to host colonies by the end of the century.
Believe it or not, I wrote the title of this post before reading past the second paragraph of the article or clicking the link to the Scientific Reports paper. So, now let’s click the link to see if I have to change the title…
The contribution of climate change to shifts in a species’ geographic distribution is a critical and often unresolved ecological question. Climate change in Antarctica is asymmetric, with cooling in parts of the continent and warming along the West Antarctic Peninsula (WAP). The Adélie penguin (Pygoscelis adeliae) is a circumpolar meso-predator exposed to the full range of Antarctic climate and is undergoing dramatic population shifts coincident with climate change. We used true presence-absence data on Adélie penguin breeding colonies to estimate past and future changes in habitat suitability during the chick-rearing period based on historic satellite observations and future climate model projections. During the contemporary period, declining Adélie penguin populations experienced more years with warm sea surface temperature compared to populations that are increasing. Based on this relationship, we project that one-third of current Adélie penguin colonies, representing ~20% of their current population, may be in decline by 2060. However, climate model projections suggest refugia may exist in continental Antarctica beyond 2099, buffering species-wide declines. Climate change impacts on penguins in the Antarctic will likely be highly site specific based on regional climate trends, and a southward contraction in the range of Adélie penguins is likely over the next century.
Adélie penguin CRHS models show the spatial distribution of novel climate and changes in CRHS compared to historic observations (Fig. 2). All CRHS models performed well (area under the curve (AUC) > 0.85) and confirmed the importance of SST, SIC and bare rock to penguin chick-rearing habitats (see Supplemental Results). In this study, novel climate is SST or SIC outside the range of average SST and SIC observations from 1978–1984 (−2.42 > SST > 1.55 °C, SIC > 95.41%), which corresponds to CRHS model training data (see methods). Interestingly, ~1.5 °C was roughly the warmest SST that increasing Adélie penguin populations experienced throughout the entire satellite record while many decreasing populations experienced SST warmer than this threshold (Supplemental Fig. 1). The WAP experienced the greatest number of novel climate years, with up to seven years of novel climate from 1981–2010 and over 40 years of novel climate using an ensemble of global climate model projections from 2011–2099 (Fig. 2a, see Supplemental Figs 2–9 for individual climate model output and Supplemental Fig. 10 for variability). Marguerite Bay appears to be on a slower warming trajectory compared to the WAP (Fig. 2a), which is also evident in the high-resolution GFDL-CM2.6 projections (Supplemental Fig. 9). While both the WAP and Ross Sea regions have been characterized by high CRHS in the recent past (Fig. 2b), our model projects a substantial decrease in CRHS along the WAP and an increase in CRHS in the Ross Sea over the next century (Fig. 2c). The Cape Adare region, home to the earliest known occupation and the largest Adélie colony4, had no novel climate and high CRHS in the past and future (Fig. 2a,b). CRHS in the Cape Adare region is also projected to increase in the future (Fig. 2c, Supplemental Fig. 11). At Cape Adare, SST is projected to increase from about −1 °C to 0 °C and SIC is projected to decrease from ~20% to ~10% by 2100 (Supplemental Fig. 11), with these changes in SST and SIC shifting towards peak suitability (see response curves, Supplemental Fig. 12). The northeastern Antarctic Peninsula appears to be a more favorable environment than the southwestern Antarctic Peninsula (Fig. 2a,b). From 1981–2010, the South Shetland Islands and the WAP had a similar number of novel climate years and mean CRHS (Fig. 2a,b) but CRHS improved in the South Shetland Islands (Fig. 2c). During this time, the more northerly South Sandwich and South Orkney Islands experienced no years with novel climate, higher mean CRHS and improved CRHS compared to southerly islands and the WAP. Comparing two species distribution modeling approaches and two spatial subsets of the presence-absence data, we found the modeling methods (MaxEnt vs. GAMs) produced similar results but varied more when presence or absence data was incomplete. Model output was most sensitive to incomplete absence data, especially when true presence data was included, perhaps because absence data was missing within a specific environmental niche and Adélie penguins do not occupy all available habitats (Supplemental Results).
It appears that the penguins are doomed by cumulative “novel climate years.” How did the authors calculate future “novel climate years”?
RCP 8.5, of course! The paper even cites Deconto & Pollard.
Figure 4 from the paper…
From the supplemental information…
Maybe some Red State AG’s can investigate this. Alarmist nonsense based on bad science fiction (RCP 8.5) must qualify as fraud.
Fraud must be proved by showing that the defendant’s actions involved five separate elements: (1) a false statement of a material fact,(2) knowledge on the part of the defendant that the statement is untrue, (3) intent on the part of the defendant to deceive the alleged victim, (4) justifiable reliance by the alleged victim on the statement, and (5) injury to the alleged victim as a result.
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Addendum: RCP 8.5 Explained
RCP 8.5 = Relative Concentration Pathway 8.5
In most, if not all, catastrophic AGW papers, RCP 8.5 (or an equivalent) is invoked as a “business as usual scenario.” A recent example can be found here. The peer-reviewed paper said, “Antarctica has the potential to contribute more than a metre of sea-level rise by 2100.” This was translated by journalists into, “Antarctic ice sheets are expected to double sea-level rise to two metres by 2100, if carbon emissions are not cut.”
There is a world of difference between “has the potential to” and “are expected to,” particularly when the “potential” is based on an insanely unrealistic scenario.
The Stuff Nightmares Are Made From
Dr. Judith Curry has a very thoughtful discussion of RCP 8.5, “the stuff nightmares are made from,” on her Climate Etc. blog…
(1) AN INTRODUCTION TO SCENARIOS ABOUT OUR FUTURE
In AR5 four Representative Concentration Pathways (RCPs) describe scenarios for future emissions, concentrations, and land-use, ending with radiative forcing levels of 2.6, 4.5, 6.0, and 8.5 W/m2 by 2100. Strong mitigation policies result in a low forcing level (RCP2.6). Two medium stabilization scenarios lead to intermediate outcomes: (RCP4.5, RCP6.0).
RCP8.5 gets the most attention. It assumes the fastest population growth (a doubling of Earth’s population to 12 billion), the lowest rate of technology development, slow GDP growth, a massive increase in world poverty, plus high energy use and emissions. For more about the RCPs see “The representative concentration pathways: an overview” by Detlef P. van Vuuren et al, Climatic Change, Nov 2011.
RCP8.5 assumes a nightmarish world even before climate impacts, resulting from substantial changes to long-standing trends. It provides AR5 with an essential worst case scenario necessary for conservative planning.
Unfortunately scientists often inaccurately describe RCP8.5 as the baseline scenario — a future without policy action: “a relatively conservative business as usual case with low income, high population and high energy demand due to only modest improvements in energy intensity” from “RCP 8.5: A scenario of comparatively high greenhouse gas emissions” by Keywan Riahi et al in Climate Change, November 2011, This is a material misrepresentation of RCP8.5. Scientists then use RCP8.5 to constructhorrific visions of the future. They seldom mention its unlikely assumptions.
“Scientists then use RCP8.5 to construct horrific visions of the future.” Why would “scientists” feel compelled “to construct horrific visions of the future”? Furthermore, why would they so often describe these “horrific visions of the future” as baseline, expected or “business as usual” scenarios?
Based on a real world “business as usual” emissions scenario, with natural gas displacing oil at its current pace and no carbon tax, I come up with a CO2 right about inline with RCP 6.0, “a mitigation scenario, meaning it includes explicit steps to combat greenhouse gas emissions (in this case, through a carbon tax)“.
Then I took my real world “business as usual” relative concentration pathway and applied three reasonable climate sensitivities to it: 0.5, 1.5 and 2.5 °C per doubling of atmospheric CO2, starting at 280 ppmv (TCR 0.5, TCR 1.5 and TCR 2.5). HadCRUT4, referenced to 1850-1879 is clearly tracking very close to TCR 1.5…
Since it is generally assumed that at least half of the warming since 1850 was natural, the actual climate sensitivity would have to be significantly lower than 1.5 °C per doubling. Therefore, RCP 8.5 should never be described as “business as usual,” “expected” or a “baseline case.” Since its assumptions are mind mindbogglingly unrealistic, it shouldn’t be used in any serious publication. It is bad science fiction.