There have been a number of recent news articles and scientific papers regarding the status of the Antarctic ice sheet. Some are reporting that the ice is growing and others that it is melting - who are we to believe?
A recent study published in the Journal of Glaciology by NASA outlined that widespread snowfall that has accumulated over the last 10,000 years has exceeded the melting of the ice. A news article from Global News has outlined the study. Jay Zwally, a glaciologist with NASA Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study, which was published on Oct. 30 in the Journal of Glaciology has calculated ice accumulation and melting. Ice in East Antarctica in particular has been shown to have increased in size by around 0.7 inches per year over the last 10,000 years. This is argued by NASA to have been enough to outweigh the melting of Antarctica's glaciers. In contrast, NASA has also agreed that some areas of West Antarctica are melting but overall believe that the ice is growing instead of melting. Olga Sergienko, a research glaciologist with the National Oceanic and Atmospheric Administration (NOAA) has said however that there are problems with these results due to a lack of data and the hostile environment the data needs to be collected in.
On the other hand, many other studies including the Intergovernmental Panel on Climate Change’s (IPCC) 2013 report say that Antarctica is overall losing land ice, mainly around the Antarctic Peninsula. In 2008, satellite data found that, on average, the continent is losing about 134 billion metric tons of ice per year. In my opinion, I agree with most other scientists that the west Antarctic ice sheet is decreasing and is adding to rising sea levels and that the East Antarctic ice is also melting, albeit at a slower pace. This opinion concurs with other scientists who have calculated that in the last decade, observations show that the melting in Antarctica, the Arctic and Greenland have risen the oceans by 12mm. The melting of the entire western ice sheet could cause a 4m sea level rise. This video shows the scale of the melting of the Antarctic ice sheet. In the future, this could only increase with the further melting of the crumbling cryosphere in both Antarctica and the Arctic.
Figure 1: This graph from NASA's Grace satellites illustrates that ice is being lost since 2008 (source).In conclusion, there is no clear picture or view on whether the Antarctic ice is melting or growing. East Antarctica's melting status is an enigma and will continue to be until further research is carried out. The consensus and personal opinion has been that it is melting but NASA's research of mass changes in ice must also be considered in the coming years.
The next post will concentrate on the NASA report and its flaws and successes.
If the antarctic ice sheet is melting, what likely effects will this have on the animals and plants which inhabit it and the surrounding waters? I feel like a lot of attention gets given to the Arctic, as you said, with all the pictures of polar bears on ice rafts - but what is going to happen to the penguins?!
ReplyDeleteThanks for posting Ben! I think as the waters around Antarctica warm, the ocean will become less nutrient rich (nutrients is most abundant in cold waters) so will reduce the number of species able to survive there. With this warming and reduced nutrients the penguins will suffer along with the thinning of the ice near their breeding grounds.
DeleteHi Laura, very interesting blog-post. In most scenarios researchers only give attention to the Arctic, neglecting the Antarctic. Although not completely convinced that the Antarctic ice sheet is expanding, hypothetically if the Antarctic sheet is expanding to what degree do you believe this would help various species adapt to cool climates? As I feel that due to being on the other side of the world (literally) it may be very difficult for these species to migrate long distances away from their natural habitat to find similar conditions for the livelihood. What do you think?
ReplyDeleteThanks for your post Maria! I guess the reason people focus on the Arctic melting is because most of the world's population live in the northern hemisphere and it is melting faster than the Antarctic. I think if the ice sheet of Antarctica expands, it will benefit the penguins and other animals that depend on the thickness of the ice, particularly for breeding. Species would not have to migrate as far if there is more ice and if the waters around Antarctica cool, there could be extra nutrients, benefiting the species that migrate to and live in Antarctica.
DeleteI totally agree however, wouldn't they have to migrate through warm waters before they are able to reach the cool waters of the Antartica? Do you think they would be able to survive through travelling in different temperatures of water?
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