The impact of climate change on the Antarctic Peninsula

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Hello, I’m Benjamin Parra, I’m currently doing an Environmental Management degree at Western Sydney University and I’ll be talking to you about the impact of climate change on the Antarctic Peninsula. One of the most serious challenges the world currently faces is climate change. During the 20th century the surface of the Earth warmed by an average of 0.6°C and from the nineteen fifties most of the warming has probably been due to greenhouse gases. Greenhouse gases in the lower atmosphere change the Earth’s climate by absorbing infra-red thermal radiation emitted by the Earth and re-emitting it. Unless a considerable global effort to minimize greenhouse gas emissions from human activities commences, most of them will keep increasing, as they are related to how many people obtain their food and energy. The Antarctic Peninsula has been warming rapidly since the 1950s and is one of the places on Earth where global warming is having its greatest effects. Between 1957 and 2006, temperatures in the Antarctic Peninsula have increased by approximately six degrees Celsius, which is more than five times the global average.

The Antarctic Peninsula is an important place to research future global sea level rise. Warming of the Antarctic Peninsula is linked to changes in the duration and amount of sea ice, snow cover, glaciers retreating and increases in oceanic heat content over the Antarctic Peninsula ice shelves. In the West Antarctic Peninsula, the ice season is almost 90 days shorter, 87% of glaciers are retreating, sea ice older than one year no longer exists and these changes are increasing in speed. Penguins are sensitive to climate change and have for a long time been regarded as good indicators of environmental change. Changes in sea ice will probably have a great impact on ocean circulation and are believed to directly affect the penguins in the Antarctic Peninsula. The chinstrap penguin is a species of penguin that lives in the Antarctic Peninsula. Chinstrap penguin numbers have been declining throughout the South Shetlands. Deception Island is a volcanic island located in the South Shetlands and is home to the largest colony of chinstrap penguins in Antarctica. Chinstrap penguins at Baily Head located on the eastern shore of Deception Island had decreased by at least 50% from 1987 to 2011.

Between 2003 to 2010 Chinstrap penguins at Baily Head decreased by approximately 39%. The best explanation for the large reduction of chinstrap penguins may be due to changes in the abundance of Antarctic krill. Antarctic krill are the main food source for the chinstrap penguin. The marine ecosystem in the West Antarctic Peninsula is supported by phytoplankton blooms. Since 1980 there has been a 12% reduction of phytoplankton blooms in the West Antarctic Peninsula. The changes in phytoplankton blooms affect Antarctic krill directly. Antarctic krill are the main food source for most of the vertebrates in the Antarctic Peninsula like penguins, flighted sea birds, baleen whales, seals and fish. Sea ice cover is linked to the population size of krill. Reduced numbers of krill have considerable consequences in the ecosystems of the Antarctic Peninsula. From the 1970s to 2010 reductions in sea ice have been attributed for up to an 80% decrease in krill density. Carbon dioxide is the greenhouse gas responsible for most of the warming caused by human activities. Even if carbon dioxide emissions caused by human activities stopped completely, it would most likely take over 1,000 years for the effects it has had on global warming to reverse.

To attain a continued balance in future radiative forcing from long-lived greenhouse gases it is necessary to considerably decrease carbon dioxide emissions, if all the greenhouse gas emissions other than carbon dioxide caused by human activities were diminished to zero from 2010 onwards, it would not be enough to counteract the effects of the predicted increase of carbon dioxide emissions over the next 34 years..

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