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Antarctica Transport

The Antarctic Snow Cruiser was a vehicle designed from 1937 to 1939 under the direction of Thomas Poulter, intended to facilitate transport in Antarctica during the United States Antarctic Service Expedition (1939–41). The Snow Cruiser was also known as "The Penguin," "Penguin 1" or "Turtle" in some published material.

Poulter had been second in command of Byrd's Second Antarctic Expedition, launched in 1934. From his time in the Antarctic, Poulter had devised several innovative features. However, the massive Snow Cruiser generally failed to operate as hoped under the difficult conditions, and was eventually abandoned in Antarctica. Rediscovered under a deep layer of snow in 1958, it later disappeared again due to shifting ice conditions.

Physics Antarctica

The lowest natural temperature ever directly recorded at ground level on Earth is −89.2 °C (−128.6 °F; 184.0 K) at the Soviet Vostok Station in Antarctica on 21 July 1983 by ground measurements.

On 10 August 2010, satellite observations showed a surface temperature of −93.2 °C (−135.8 °F; 180.0 K) at 81.8°S 59.3°E / -81.8; 59.3, along a ridge between Dome Argus and Dome Fuji, at 3,900 m (12,800 ft) elevation. The result was reported at the 46th annual meeting of the American Geophysical Union in San Francisco in December 2013; it is a provisional figure, and may be subject to revision. The value is not listed as the record lowest temperature as it was measured by remote sensing from satellite and not by ground-based thermometers, unlike the 1983 record. The temperature announced reflects that of the ice surface, while the Vostok readings measured the air above the ice, and so the two are not directly comparable. More recent work shows many locations in the high Antarctic where surface temperatures drop to approximately −98 °C (−144 °F; 175 K). Due to the very strong temperature gradient near the surface, these imply near-surface air temperature minima of approximately −94 °C (−137 °F; 179 K).

Climate change Environment Antarctica Glaciers

The Western Antarctic Ice Sheet (WAIS) is the segment of the continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains that lies in the Western Hemisphere. The WAIS is classified as a marine-based ice sheet, meaning that its bed lies well below sea level and its edges flow into floating ice shelves. The WAIS is bounded by the Ross Ice Shelf, the Ronne Ice Shelf, and outlet glaciers that drain into the Amundsen Sea.

New Zealand Antarctica

The McMurdo Dry Valleys are a row of largely snow-free valleys in Antarctica, located within Victoria Land west of McMurdo Sound. The Dry Valleys experience extremely low humidity and surrounding mountains prevent the flow of ice from nearby glaciers. The rocks here are granites and gneisses, and glacial tills dot this bedrock landscape, with loose gravel covering the ground. It is one of the driest places on Earth and has not seen rain for nearly 2 million years.

The region is one of the world's most extreme deserts, and includes many features including Lake Vida, a saline lake, and the Onyx River, a meltwater stream and Antarctica's longest river. Although no living organisms have been found in the permafrost here, endolithic photosynthetic bacteria have been found living in the relatively moist interior of rocks, and anaerobic bacteria, with a metabolism based on iron and sulfur, live under the Taylor Glacier.

Climate change Environment Geography Antarctica Arctic Geology Globalization Science Policy Weather Sanitation

Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

The largest driver of warming is the emission of gases that create a greenhouse effect, of which more than 90% are carbon dioxide (CO
2) and methane. Fossil fuel burning (coal, oil, and natural gas) for energy consumption is the main source of these emissions, with additional contributions from agriculture, deforestation, and manufacturing. The human cause of climate change is not disputed by any scientific body of national or international standing. Temperature rise is accelerated or tempered by climate feedbacks, such as loss of sunlight-reflecting snow and ice cover, increased water vapour (a greenhouse gas itself), and changes to land and ocean carbon sinks.

Temperature rise on land is about twice the global average increase, leading to desert expansion and more common heat waves and wildfires. Temperature rise is also amplified in the Arctic, where it has contributed to melting permafrost, glacial retreat and sea ice loss. Warmer temperatures are increasing rates of evaporation, causing more intense storms and weather extremes. Impacts on ecosystems include the relocation or extinction of many species as their environment changes, most immediately in coral reefs, mountains, and the Arctic. Climate change threatens people with food insecurity, water scarcity, flooding, infectious diseases, extreme heat, economic losses, and displacement. These impacts have led the World Health Organization to call climate change the greatest threat to global health in the 21st century. Even if efforts to minimise future warming are successful, some effects will continue for centuries, including rising sea levels, rising ocean temperatures, and ocean acidification.

Many of these impacts are already felt at the current level of warming, which is about 1.2 °C (2.2 °F). The Intergovernmental Panel on Climate Change (IPCC) has issued a series of reports that project significant increases in these impacts as warming continues to 1.5 °C (2.7 °F) and beyond. Additional warming also increases the risk of triggering critical thresholds called tipping points. Responding to climate change involves mitigation and adaptation. Mitigation – limiting climate change – consists of reducing greenhouse gas emissions and removing them from the atmosphere; methods include the development and deployment of low-carbon energy sources such as wind and solar, a phase-out of coal, enhanced energy efficiency, reforestation, and forest preservation. Adaptation consists of adjusting to actual or expected climate, such as through improved coastline protection, better disaster management, assisted colonisation, and the development of more resistant crops. Adaptation alone cannot avert the risk of "severe, widespread and irreversible" impacts.

Under the 2015 Paris Agreement, nations collectively agreed to keep warming "well under 2.0 °C (3.6 °F)" through mitigation efforts. However, with pledges made under the Agreement, global warming would still reach about 2.8 °C (5.0 °F) by the end of the century. Limiting warming to 1.5 °C (2.7 °F) would require halving emissions by 2030 and achieving near-zero emissions by 2050.