By James B. McClintock, Ph.D.

Endowed University Professor of Polar and Marine Biology,

UAB Department of Biology

James McClintock

The Antarctic Peninsula—a region of Antarctica stretching some 1,200 miles north toward South America—is the site of the UAB marine research program I direct with UAB’s Chuck Amsler, Ph.D. In 40 years, it will be a very different place. Chuck and I have witnessed, firsthand, many of the impacts brought on by rapid climate change. Barring unforeseen shifts in climate model projections, it is likely the current warming trend on the Antarctic Peninsula will have continued, or perhaps even accelerated, in four decades. And the balance of the continent of Antarctica, so far showing only modest warming on its western sector, will likely be catching up with its more rapidly warming Arctic cousin.

Melting Glaciers

In 40 years, the peninsular Marr Glacier that once backed right up to the U.S. Palmer Research Station where we work will have continued to recede at an alarming pace. Already, glacial melting has transformed a visit to the glacier from a walk to a hike. At the base of the glacier, Amsler Island, its entirety recently unveiled in a geological wink of an eye from beneath a melting tongue of ice, will rest even further from the glacial ice. Should Chuck and Maggie Amsler visit their namesake four decades hence, they will find the broken glacial tongue long since melted from its shores.

In 40 years, the eight major ice shelves that have freed themselves from the Antarctic Peninsula will have been joined by others. In 2002, the Larson Ice Shelf breakout was the size of Rhode Island. In 2008, the Wilkins Ice Shelf breakout was the size of Connecticut. What portends 2018, 2027, or 2049? The demise of the ice shelves frees the earthbound glacial ice sheets to flow seaward, their meltwater acting as a stimulus to a global rise in sea levels.

Missing Penguins

In 40 years, the 15,000 breeding pairs of Adélie penguins that once lived within sight of Palmer Station will likely be gone. Their breeding colony, established some 700 years ago, has already been reduced in size by 70 percent since 1975. The penguins’ eggs have been lost to the unseasonable snowfall that ironically accompanies the increasing humidity brought on by warming air temperatures. The Adélie also may be suffering from malnutrition, as the annual sea ice upon which they historically marched to their rich offshore feeding grounds has diminished. Already, warming has reduced the extent and duration of the peninsular annual sea ice some 40 percent in just 25 years.

Killing of the Krill

In 40 years, the loss of the peninsular sea ice also will have dramatically reduced the once-rich populations of krill. When they are young, the shrimp-like krill depend on the dense, luxuriant growth of microalgae that accumulates on the undersurface of the sea ice for their meals. As a result, planktonic krill will likely have been replaced by salps, small jellyfish-like animals that lack the nutritional content of protein-rich krill. Collectively, the vast krill-consumers of the Antarctic Peninsula—the fish, sea birds, penguins, seals, and baleen whales—may have moved elsewhere.

Hope for the Future

But despite all this, there still remains hope. In 40 years, the seasonal hole in the ozone layer that encompasses the entire continent of Antarctica will have almost disappeared. Earth’s atmosphere, which protects the planet from deadly ultraviolet radiation from space, will be healed—the result of the 1989 Montreal Protocol. This agreement happened when a collective of nations gathered around the proverbial round table with the common goal of regulating ozone-destroying chlorofluorohydrocarbons.

Let’s hope that in 40 years humankind will be celebrating a similar effort in terms of a global cooperative to regulate greenhouse gases. If not, it may be too late for the delicate ecological balance of marine life along the Antarctic Peninsula. And sadly, on a global scale, the warning that the Antarctic Peninsula was the “canary in the coal mine” may have come to fruition.