Introduction
Antarctica is the fifth largest continent and covers the southernmost part of the earth, with most of its mass being found predominantly within the area enclosed by the Antarctic Circle. It is the planetās geographic South Pole. Antarcticaās size varies seasonally due to expanding coastal sea ice but is generally accepted to be approximately 5,400,000 square miles (14,000,000 square kilometers) in area; for context, the United States has an area of 3,600,000 square miles (9,360,000 square kilometers) (Redd, 2012). Most of Antarctica is covered in thick ice averaging 1.2 miles (2 kilometers) in thickness.
The continent is divided into two primary regions, separated by a mountain range that runs across the continent, called the Transantarctic Mountains. On either side of this range are East Antarctica and West Antarctica, respectively. East Antarctica comprises a two-thirds majority of the continentās landmass and is the more continental aspect of Antarctica; it is covered in sheet ice. West Antarctica comprises the smaller one-third of the continentās landmass and consists of a series of islands that stretch toward the southernmost tip of South America; a smaller continental area that is covered in sheet ice, the Ronne Ice Shelf on the Weddell Sea side of West Antarctica, and the Ross Ice Shelf on the Ross Sea side of West Antarctica. The West Antarctica continental ice sheet currently sits below sea level and is warmer than the higher-elevation East Antarctica, which is colder due to this higher elevation and more continental influences in the interior (Redd, 2012).
Despite all of its ice, Antarctica is a designated polar desert, with a large area of the East Antarctic ice sheet receiving less than 5 cm of water equivalent snowfall a year (Turner et al., 2009). Most of the snowfall received in Antarctica is in the coastal regions. To date, Antarctica has approximately one-tenth of the planetās land surface, which includes 90% of earthās ice and 70% of its fresh water (Kennicutt et al., 2014).
There are no permanent indigenous inhabitants living on Antarctica; however, there are several governments that have permanently manned research stations and field camps on the continent and nearby islands. These stations and camps are manned by scientists and researchers from around the world, with the population fluctuating depending on the season. The summer season brings an increase in the number of staff.
Antarctica is claimed by Argentina, Australia, Chile, France, New Zealand, Norway, and the United Kingdom, with the United States and Russia having reserved the right to make claims (the United States does not recognize any other international claims). There have been no formal claims in the sector between 90 degrees west and 150 degrees west (Central Intelligence Agency, 2018). The governing of Antarctica is done based on an international treaty signed in 1959, the Antarctic Treaty, as well as three other major international agreements: the 1972 Convention for the Conservation of Antarctic Seals, the 1980 Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR), and the 1991 Protocol on Environmental Protection to the Antarctic Treaty (Australian Government, 2016a, 2017).
Climate Change in Antarctica
According to Clarke, Johnston, Murphy, and Rogers (2007), three areas of the globe are currently experiencing rapid climate change in their regions: the Antarctic Peninsula, northwestern North America, and an area in central Siberia. Rapid warming of the Antarctic Peninsula has drawn considerable attention and concern, although a significant meteorological trend of increased temperatures across the continent is yet to be seen: some regions are warming and others are cooling (Clarke et al., 2007). As will be discussed later in this chapter, more data and research is needed to understand the processes and factors that are occurring. A significant portion of the current data is focused on the coastal regions of the continent (Clarke et al., 2007). Larsen et al. (2014) have reported that the strongest rates of warming are occurring in the western Antarctic Peninsula.
Effects of Climate Change
The effects of climate change on Antarctica are both tangible and unknown. Some of the tangible effects include:Some climate change effects, vulnerability, and areas affected are depicted in Table 1.
- Sea ice and physical environment changes to the west of the Antarctic Peninsula
- Ecological effects stemming from decreased duration and extent of ice and snow cover, enhanced permafrost thaw, and changes in precipitation-evaporation balance
- Inability of natural systems, wildlife, flora, and other organisms to adapt at the increased pace of climate change
- Increased vulnerability to invasions by non-indigenous species
- Ocean acidification
- Melting of the large ice sheet of West Antarctica
- Loss of ice sheets and significant loss of snow and ice banks, resulting in more open ground
Table 1
Some effects of climate change and areas affected in Antarctica
Climate change effect | Vulnerability | Areas affected |
|---|---|---|
Sea ice and physical environment changes to the west of the Antarctic Peninsula | Altering stocks and productivity of phytoplankton and krill, leading to potential effects in the Patagonian toothfish fisheries and Patagonian and Antarctic krill fisheries | Sea ice to the west of the Antarctic Peninsula; ocean fisheries in Patagonia and Antarctic |
Ecological effects stemming from decreased duration and extent of ice and snow cover, enhanced permafrost thaw, and changes in precipitation-evaporation balance | Terrestrial and freshwater ecosystems | Antarctic freshwater systems (lakes, ponds, short streams, and seasonally wetted areas); continental lakes; aquatic ecosystems of Antarctica |
Inability of natural systems, wildlife, flora, and other organisms to adapt at the increased pace of climate change | Biodiversity loss; possible loss of tourism stemming from this loss of biodiversity, loss or endangered status of the wildlife tourists seek to see in Antarctica | Antarctic continent and ocean surrounding Antarctica |
Increased vulnerability to invasions by non-indigenous species | Terrestrial ecosystems | Antarctic continent |
Ocean acidification | Embryos of Antarctic krill; potentially the larger krill fishery | Ocean surrounding Antarctica; food webs in Antarctica and its surrounding ocean; larger krill fishery as a whole (Antarctica, Patagonia) |
Melting of the large ice sheet of West Antarctica | Potential for significant climate-induced sea-level rise | Global |
Loss of ice sheets, significant loss of snow and ice banks | Consequent increase in open ground, exacerbating warming trends | West Antarctica; Antarctic Peninsula |
Sea Ice and Physical Environment Changes
Climate change is affecting both land and sea in Antarctica (Clarke et al., 2007). Changes to sea ice and the physical environment to the west of the Antarctic Peninsula have been found to be altering phytoplankton and krill stocks and productivity (Larsen et al., 2014), leading to potential effects in the Patagonian toothfish fisheries and Patagonian ...