Antarctica travelogue at the Cary Institute

MILLBROOK — Cary Institute’s auditorium was packed Friday night, Jan. 8, for an engaging Antarctica travelogue complete with photos of penguins and scientific charts given by the institute’s president, William Schlesinger. Speaking extemporaneously, Schlesinger gave an informative lecture focused on environmental impacts on the Antarctica ecosystem.

“The reason to go to Antarctica is to see the penguins,†Schlesinger said, and observed that it is difficult to resist imitating their walk. “The protocol is to stay at least 15 feet away from them, but if you are quiet and patient they will come up to you because they are curious,†he said.

Antarctica abounds in other life — seals, whales, birds, jellyfish.

“What is going on with the ice should be of concern to all of us,†Schlesinger said as he began the scientific part of his lecture. He explained the difference between sea ice and glacial ice. The continent of Antarctica, which is approximately the size of the United States, has both types of ice, while the Arctic is composed entirely of sea ice. Sea ice expands and contracts seasonally and does not impact sea levels. Although there appears to be a decrease in the area of sea ice in Antarctica in recent years, it is not statistically clear that this is a long-term trend.

“Glacial ice is very different,†Schlesinger explained. It is created as snow accumulates on Antarctica’s continental land mass, becomes compressed and slowly flows in all directions. As glacial ice moves outward to the ocean’s edge, it breaks into giant icebergs. Schlesinger said that records from certain station locations show thinning of glacial ice, while in other areas the ice is growing thicker. In his opinion, “the overall ice balance is negative,†and the melting is contributing to rising global ocean levels, as recorded since 1880.

Schlesinger praised global cooperation for stabilizing the ozone hole, which appears from August to December over Antarctica, as a “environmental success story.â€

In 1974 Sherwood Rowland, a scientist at University of California (Berkeley), predicted that the earth’s protective ozone layer would be depleted by the chlorofluorocarbons (CFCs) then found in aerosols and freon refrigerants. In 1985 British scientists in Antarctica observed what Rowland had predicted, a rapidly expanding hole in the ozone layer. Realizing the very serious health implications of ozone depletion, the nations of the world signed the Montreal Protocol, which mandated the substitution of hydro fluorocarbons for CFCs beginning in 1989. Although the ozone hole still forms over Antarctica, its size is now stabilized. Schlesinger suggested that this example of many nations working together provides a model for global climate change negotiations.

After humorous photos of white, pink and black penguin feet, Schlesinger turned to the impact of global warming on Antarctic wildlife. With the rise of sea levels and warmer waters, krill, the primary food for many ocean animals, are decreasing.

“What we do in the temperate zone plays out in the survival of species,†Schlesinger said.

Gentoo penguins seem to be doing well in the warmer environment, but the Adelie penguin population is declining rapidly. He observed, “They don’t ask much — just krill and a place to nest.â€

The 60 to 80 cruise ship visits a year contaminate the environment and disturb the penguin habitat. “When you leave, you leave a fragile world, which needs our attention and stewardship.â€

In a later conversation with The Millerton News, Schlesinger mentioned the recent renegotiation of the Antarctic Treaty, which will limit the estimated 45,000 annual tourist visits to Antarctica.

At the end, Schlesinger took a series of interesting questions from the audience, most of which were about global warming rather than Antarctica or penguins.

“What causes krill to decrease?â€

He answered, “Over-fishing, and the warmth of the water.â€

Another asked, “Is there an ozone hole over the North Pole?â€

He explained that extreme cold in the stratosphere, in excess of minus 50 degrees, is not present at the North Pole.

There were some members of the audience who expressed doubt about man’s contribution to climate change. One asked if underwater volcanic activity could be responsible for warming the ocean, which Schlesinger refuted.

“I’m a big believer that the science of global warming is solid and that it is caused, at least partially, by human activity,†Schlesinger said. He later said he, “gets these kind of questions all the time, and is glad to provide a large audience with a scientific explanation.â€

The last question Schlesinger took was from a “young hand at the back of the audience.†The little girl asked the one question he said he could not answer. “Why is Antarctica called Antarctica?â€

The next lecture at the Cary Institute of Ecosystem Studies, which Schlesinger said “should be a barn burner,†will be Dr. James Hansen presenting his new book, “Storms of My Grandchildren: The Truth about the Coming Climate Catastrophe and Our Last Chance to Save Humanity,†on Friday, Feb. 5. To learn more, log onto caryinstitute.org.