ESA’s 2022 emperor penguin record used Antarctic sea ice fashions which might be identified to be flawed

From polar bear science

Susan Crockford

While Arctic sea ice has declined remarkably since 1979, Antarctic ice has been unexpectedly stable. Experts concede that existing climate models – which assume CO2 emissions are driving global sea ice loss – had predicted that Antarctic sea ice would have been shrinking in recent decades – and would shrink even more in the future. They finally admitted they were wrong.

John Turner (British Antarctic Survey) and Josifino Comiso (NASA) in a NATURE article in 2017:

“Current climate models struggle to simulate the seasonal and regional variability observed in Antarctic sea ice.”

A new model released earlier this year suggests that Antarctica’s virtually stable sea-ice coverage, which has existed for the past four decades, is now projected to last for nearly another three decades until at least 2050, and only slowly decrease thereafter (Rackow et al. 2022).

However, emperor penguin researchers used the old flawed models to list the species as “threatened” in the US just a few months ago due to predicted sea ice loss (Jenouvrier et al. 2009; Jenouvrier et al. 2020; Trathan et al. 2020; USFWS 2022) .

In other words, it’s not just that penguin researchers have chosen the most pessimistic and utterly improbable “worst case” scenario to support their arguments, as polar bear specialists are so fond of doing (Crockford 2019; Hausfather and Peters 2020): sea ice experts now say these old sea ice models are quite useless for predicting future sea ice conditions and have known this for more than a decade (Blanchard-Wrigglesworth et al. 2021, 2022; Comiso et al. 2017; Turner and Comiso 2017; Turner and Overland 2009; Turner et al 2013).

Sea-ice experts knew the models regarding Antarctic sea ice and CO2 were wrong – and wrote about their concerns in the scientific literature – yet penguin biologists ignored this evidence and continued to insist that future sea ice loss in Antarctica doomed penguins to extinction Ocean. See graph below, from Jenouvrier et al. 2020:

ESA protection for Emperors was granted by US Fish & Wildlife on October 25, 2022, although a new Antarctic sea ice model was released more than eight months earlier, on February 2, 2022. This means that both the petitioners for the ESA list and the USFWS ignored years of evidence from trusted experts that Antarctic sea ice models were not fit for purpose, plus a more plausible option then offered, all calling it “best available science.” “.

The new model may be crap too, but that doesn’t justify ignoring solid evidence that the old one was seriously flawed.

The following graph is from the Turner and Comiso paper and shows the worrying discrepancy: summer arctic ice vs. Antarctic winter ice (September for both) from 1979-2017, with the maximum for Antarctic ice reaching 20.11 mkm2 in 2014 (when Arctic ice was the sixth lowest at 5.02 mkm2):

This chart ends in 2017, five years ago. Below was the extent on September 19, 2022, near the maximum for that year, eventually reaching 18.19 mkm2. Lots of ice for emperor penguins who lay their eggs and raise young in winter/spring, mainly on solid ice:

As an aside, I couldn’t help but notice that emperor penguin researchers working in Antarctica are focused on winter sea ice for future health and survival, while polar bear specialists and other Arctic biologists are most concerned about summer sea ice loss. In both cases, the ice-dependent species require winter/spring sea ice for reproduction and/or food. The difference is that summer sea ice in Antarctica has almost always disappeared over the summer (up to 15% or less than winter) and no one is claiming that any Antarctic animal needs summer sea ice to survive. Strange that.


Bird Life International. 2020 Aptenodytes forsteri. The IUCN Red List of Threatened Species 2019: e.T22697752A132600320. Downloaded October 26, 2022.

Blanchard-Wrigglesworth E, Eisenman I, Zhang S, et al. 2022. New perspectives on the mystery of Antarctic sea ice extent, Eos 103.

Blanchard-Wrigglesworth E, Roach LA, Donohoe A and Ding Q 2021. Influence of Southern Ocean winds and SSTs on Antarctic sea ice trends and variability. Journal of Climate 34(3):949-965.

Hausfather, Z. and Peters, GP 2020. Emissions – the business as usual story is misleading [“Stop using the worst-case scenario for climate warming as the most likely outcome — more-realistic baselines make for better policy”]. Nature 577: 618-620

Jenouvrier S, Caswell H, Barbraud C, Holland M, Stroeve J and Weimerskirch H 2009. Demographic models and IPCC climate projections predict a population decline of emperor penguins. Proceedings of the National Academy of Science USA 106: 1844-1847. Available here:

Jenouvrier, S. et al. 2020 The goals of the Paris Agreement will likely halt future declines in emperor penguins. Global Change Biology 26(3): 1170-1184. [paywalled]

Rackow, T., Danilov, S., Gössling, HF et al. 2022. Delayed sea-ice retreat in Antarctica in high-resolution climate change simulations. Nature Communications 13:637.

Trathan, PN et al. 2020 The Emperor Penguin – Vulnerable to projected rates of warming and sea ice loss. Biological Conservation 241:108216. [open access]

Turner, J. and Comiso, J. 2017. Solve the Antarctic sea ice puzzle. Nature 547:275-277.

Turner, J. and Overland, J. 2009. Different climate change in the two polar regions. Polar Research 28(2):146-164.

Turner J, Bracegirdle TJ, Phillips T et al. 2013 A first assessment of the Antarctic sea ice extent in the CMIP5 models. Journal of Climate 26(5):1473-1484.

USFWS 2022. “Endangered and threatened wildlife and plants; Endangered species status for the emperor penguin under Section 4(d) of the Rule.’ Federal Register 87(206):64700-64720.

Like this:

Like Loading…

Comments are closed.