Local evidence for climate change is there: droughts and heat waves in July. However, there are unseen, far more significant changes in areas most of us will never visit, such as Marion Island and the Southern Ocean which surrounds Antarctica.
Local evidence for climate change is there: droughts and heat waves in July. However, there are unseen, far more significant changes in areas most of us will never visit, such as Marion Island and the Southern Ocean which surrounds Antarctica.
Hidden in the sub-Antarctic, approximately 1 770km from Port Elizabeth, Marion Island is untouched by humans and has been a haven for scientific observation since 1965. Through studying such a remote environment, scientists are able to analyse the specific effects of climate change on ecosystems.
Prof Ian Meiklejohn of Rhodes University's Department of Geography, along with fellow researchers, monitors changes in the island’s landscape to measure the impacts of our climate. At one time, parts of Marion Island remained frozen throughout the year, but warming temperatures have resulted in melting. An increase in landslide and mudslides could be linked to the loss of ground stability, once provided by ice.
Not only are the landscapes shifting, but our oceans are disturbed by changing temperatures. The Southern Ocean is currently the world's largest sink for carbon dioxide. Its large expanse and cool temperatures effectively dissolve greenhouse gases. However, as water temperatures increase, its ability to do this diminishes. Consequently, more carbon dioxide is released into the atmosphere.
Animal species are also vulnerable. “There are a number of indications that global climate change is affecting the biology in the oceans around Antarctica,” says William Froneman, Rhodes University marine biologist.
Carbon dioxide acidifies ocean water, causing conditions that are detrimental for small but vital species. For example, the shells of some types of oceanic snails are no longer forming properly. Although these animals lack the charm of the polar bear or penguin, they are an essential link in the food chain as they ultimately guarantee the survival of other larger sub-Antarctic species.
Perhaps what we cannot see may prove more ominous for our earth. “Our pollution can be recorded on the other side of the world,” says Meiklejohn, encouraging us to think about or daily habits. Through thinking globally but taking action locally, like cycling instead of motoring, we can protect the habitats of the most delicate but critical species.
Melting climate clichés
When a giant ice island, four times the size of Manhattan, smashed into the sea it seemed an ominous sign for climate change. But the break off of the Petermann Glacier from Greenland’s northwest coast in August was the biggest in almost 50 years.
“Global temperatures are increasing, there’s no debate about that,” says Professor Meiklejohn. However, Meiklejohn maintains that ice breakup is a complex situation. Fractures in ice can occur even while ice is being generated. Cracks form naturally with the movement of seawater, and sections may eventually break off. “It’s difficult to determine the main causes,” Meiklejohn says, “However, through climate warming you can get a more rapid breakup of ice.”
Meiklejohn notes that although, in general, temperatures are rising, changes in sea currents from glacial melting could cause dramatic cooling in some areas. Land temperatures in western Europe are kept moderate by the warming effects of the Gulf current. One theory is that if Greenland were to melt, the Gulf current would be interrupted by its icy, glacial water. Europe and Asia would experience an unusually cold winter and if the ice did not lift with the spring, it would act as a reflector to the sun’s warmth and could cause long term cold temperatures.
