The Antarctic Peninsula – The canary in the climate cage?
For many years miners who worked long hard hours in deep underground caves would hang a canary in a cage nearby. If the canary began to show signs of stress, it let them know the environment in the cave was changing dangerously and it was time to get out!
Dramatic environmental changes that have been occurring on the Antarctic Peninsula may foretell a similar story for all of Antarctica. Here, on the Peninsula, air and sea temperatures have risen steadily over the past 30 years. The elevated temperatures have led to the disintegration of huge pieces of a number of “permanent” ice shelves including the Larson Ice Shelf in 2002. The massive break-out that was literally the size of France!
Rising air and sea temperatures have also been linked to declines in some penguin populations. For example, increased snowfall from the warmer temperatures is burying Adélie penguin eggs and may also be harming Adélie penguins by reducing the extent of annual sea ice that provides a critical habitat for juvenile krill, small shrimp-like organisms. Krill feed on algae that grow underside of the sea ice and penguins rely on krill as a food source. In fact, there has been a startling 50% decline in the extent of annual sea ice surrounding the Peninsula over the past 30 years.
In addition, new invasive marine species have appeared along the Antarctic Peninsula including for the first time ever, large crabs. Such invaders may have arrived because of the warming conditions and may cause considerable changes in a sea floor community that is comprised of animals that are ill prepared to defend themselves against such hungry predators.
Finally, there is great concern that marine plants and animals that adapted for million of years to very stable temperatures will suffer outright death or experience dramatic changes in the rates of development of their offspring. All these ongoing and potential effects of climate warming on the organisms that live on the Antarctic Peninsula are cause for concern.
But there is hope as well. For example, when a large hole in the ozone caused by the release of CFC chemicals (chlorofluorohydrocarbons) was discovered over Antarctica in 1987, the world’s nations came together quickly and agreed to immediately stop the release of these chemicals into the atmosphere. Now scientists predict that the hole in the ozone over Antarctica will be gone by approximately 2020. This is very good news because ozone protects us and all life from harmful UV radiation. A similar strategy could be used to reduce the amounts of green house gases such as methane and carbon dioxide being released in to our atmosphere. Hopefully we can tip the tide of climate change before the dramatic changes we see already well underway in polar environments extends to the places we all call home.
Accompanying Powerpoint slides of material presented here...
Additional reading on climate change can be found here....