The Larsen B Ice Shelf breaking up, as photographed by NASA satellites in 2002. Image from NASA
Mark Linn – Contributor
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World-renowned biology professor and leading expert on Antarctic ecology James McClintock spoke to members of the community about the impact of climate change in Antarctica on the eve of a research expedition to the frozen continent.
McClintock, Ph.D., is a UAB marine and polar biology endowed professor who has been making expeditions to Antarctica for almost 30 years. On Dec. 8 he spoke to a crowd of about 50 people at Avondale Brewery about his journeys and research in Antarctica.
McClintock has written more than 200 scientific publications and several books, including “Lost Antarctica: Adventures in a Disappearing Land.” The Explorers Club recently named him a fellow in recognition of his significant contributions to the field of geographical exploration.
The event was hosted as part of Bham Now’s BOLD lecture series and sponsored by EBSCO. A portion of the proceeds went to, Hand in Paws, a charity McClintock chose.
Threat to Antarctic wildlife
Changing weather patterns cause wide-ranging and in some cases unpredictable effects on the local flora and fauna of Antarctica, according to McClintock. Unseasonable winter storms caused by shifting temperatures affect the nesting practice of a species of penguin called the Adelie penguin. Krill, a shrimp-like species at the bottom of the Antarctic food chain are becoming less common, and the less nutritious Scalps, a jellyfish-like species, are taking its place. King Crabs, which previously could not survive in the cold, shallow waters around Antarctica, are now being found closer to the continental shelf. Many rare invertebrates, such as sponges and sea anemones, evolved in Antarctica unmolested by predators with hard crushing claws such as the King Crabs. These invertebrates would have little defense against the crabs should they make it into the rapidly warming waters of their home.
Ocean acidification caused by CO2 has proven to have an adverse effect on many forms of wildlife, which indirectly impacts the predators that feed off them.
It’s all about the ice
McClintock explained in his presentation that climate change is having a dramatic effect on glaciers, ice sheets and ice shelves in Antarctica. Research has shown a high degree of warming on the western portion of the continent, including the peninsula, causing thinning of the land-locked ice sheets and the breakup of many glaciers and ice shelves such as the Larsen Ice Shelf, which extends along the east coast of the Antarctic Peninsula. In 2002, Larsen B, a portion of the shelf about the size of Rhode Island, partially collapsed into the sea. A 2015 study concluded that the remnants of Larsen B will disintegrate by the end of the decade.
Aside from the thinning ice sheets and melting glaciers, further evidence of climate change exists trapped in the ice itself. McClintock explained the process of measuring air trapped inside ice cores to determine what the atmosphere was like in ages past.
“In little air bubbles that are trapped in the ice core is the history of the atmosphere of our earth,” McClintock said. “In this case, you’re looking at a history that goes back 430 thousand years.”
The ice cores can be used to measure levels of carbon dioxide in the atmosphere. They show that there are natural changes to CO2 levels and temperature that are caused by the 100,000 year “Milankovitch Cycles” that are caused by subtle changes in Earth’s elliptical orbit. Since the Industrial Revolution, humans have added an addition 25 percent of carbon dioxide to the atmosphere, greatly contributing to the greenhouse effect.
“My take-home story to you is that these communities always change, but what’s happening right now is unprecedented in the rate of change,” McClintock said. “If organisms have thousands of years to accommodate these changes it’s possible, but for organisms such as the Adélie penguin, when these things happen on the order of decades, it’s very hard to make such changes.”
Why preserving Antarctica is important
“This ancient community of organisms that’s evolved for millions of years is a rich environment for the discovery of compounds that could fight human disease,” McClintock said.
McClintock’s team discovered one such compound in a bottom-dwelling sponge-like organism called a tunicate. The chemical, named Palmerolide after the research station, was discovered in 2004. Often when such new compounds are discovered, they’re sent to institutions such as the National Cancer Institute. Several months after the discovery, McClintock and his team were contacted by the NCI and informed that Palmerolide had shown promising results against melanoma, a form of skin cancer.
Other chemical compounds found over the years by McClintock and his teams include a protein found in an Antarctic red algae that is active against the H1N1 flu virus and a chemical found in a certain sponge that’s remarkably effective against methicillin-resistant Staphylococcus aureus, or MRSA.
“Antarctica is a fantastic repository of chemical diversity that we do not want squander for ourselves [and] for our future generations,” McClintock said.
The New Normal
One final topic McClintock touched on was how the effects of the same climate change that is wreaking havoc in Antarctica has and will continue to affect Alabama. The recent drought, which despite the rain, continues to leave almost the entire state under severe drought conditions.
“We’re going to have more intense everything,” McClintock said. “We’re going to have droughts, like we’ve always had, but they’re going to be more intense. We’re going to have freezes, like we’ve always had, but they’re going to be more intense. We certainly can expect sea level to rise, and this is happening already. “
McClintock concluded his talk on a hopeful note, bringing up recent efforts to mitigate the effects of climate change such as the Paris Climate Agreement.
“99 percent of scientists or more have decided that this is something that’s very real and something that we as a society are going to have to address,” McClintock said. “So I encourage you to encourage your friends to think about these issues.”
