Film Sparks Discussion of Fate of Penguins in the Face of Global Warming

Commentary by John C. Topping, Jr.
President, Climate Institute

A few weeks ago some of my relatives who had just seen March of the Penguins asked me what impacts global warming might have on this species. Not having yet seen the film I answered that I really didn't know but suspected that they weren't quite as threatened as the polar bear that may not be found outside zoos by the end of this

Emperor Penguins

Emperor Penguins. Photo Sharon Chester © 2005

century as warming in the Antarctic is likely to proceed much more slowly than what we anticipate for the Arctic. Now having seen this movie, the finest nature film I have ever watched and one of the best films of any kind in the past decade, I am inclined to think my initial judgment was premature. Although it does not delve into the global warming issue or speculate about impacts of climate change, March of the Penguins makes the viewer acutely aware of the fragility of existence of the Emperor Penguin. A change in the availability of food due to reductions in the krill and those creatures who feed off it could wreak havoc. So might changes in breeding grounds due to changes in sea ice or temperatures. We don't know how climate change will play out in Antarctica and how various penguin species will adapt but even now there are grounds for great concern for a wide range of penguin species.

Adelie Penguin. Photo: © Gerald & Buff Corsi, California Academy of Sciences

We have some grasp of how penguins have adapted over the past seven centuries to changes in Antarctic climate as a result of studies of abandoned colonies of Adélie Penguins. Six such abandoned colonies were excavated near Palmer Station, Anvers Island, Antarctic Peninsula. Food remains indicate that much of the food of the penguins came from mesopelagic squid and two species of fish. The research indicates that the colonies may have shifted their diet in response to warming and cooling cycles in the past. David Ainsley, a respected scientist provides a detailed look at this species in his book,The Adélie Penguin, Bellwether of Climate Change.

There is evidence of decline of a number of penguin species with explanations including human harvesting of eggs or guano used in nesting, introduction of non-native species such as rodents and, especially in areas outside Antarctica, alteration of habitat. Some of these declines have been dramatic with the Blackfooted Penguin population falling from about 575,000 in the early 1900s to about 178,000 in the late 1990s. Climate change may already have produced large reductions in populations of the Rockhopper Penguins. The number breeding on one island reportedly dropped from about 1.4 million in the 1940s to about 100,000 today with a possible explanation being a warming of surrounding waters.

Climate Change may be the leading explanation for an apparent halving of the Galapagos Penguin population since the early 1970s. .The severe El Nino event of 1982-1983 resulted in reductions estimated as about 77%. In a fascinating lecture

Galapagos Penguin. Photo: © John H. Tashjian, California Academy of Sciences.

at the Royal Society Sir Crispin Tickell describes the relationship of the El Nino Southern Oscillation to the fauna of affected areas, noting the 1982-1983 El Nino's devastating impact on Galapagos Penguins, finches and bluefooted boobies.

Evidence is accumulating that the Emperor Penguin may already be declining due to climate change. Its population has reportedly been halved over the last 50 years with an abnormally long warm spell in the Southern Ocean in late 1970s contributing to a decline of Emperor Penguins at Terre Adelie, Antarctica.

Already there are signs of rapid change in the Antarctic geography with a 1200 square mile portion of the Larsen Ice Shelf disintegrating in early 2002. It is hard to imagine that large scale changes like this, should they occur in important penguin breeding grounds, would have benign consequences.

Both the penguin and the polar bear may be threatened by emissions generated thousands of miles away. In the absence of some dramatic change in world energy trends these species may be sacrificed on the altar of industrial progress.

See National Geographic pictures

Warming, Nesting and Egg Laying