Antarctic thaw quickens, trillions of tonnes of ice raise sea levels

Antarctic thaw quickens, trillions of tonnes of ice raise sea levels

The West Antarctic ice sheet has lost almost three trillion tonnes of ice during this span - with a large chunk of the numbers coming in the last few years, according to research.

This latest IMBIE is the most complete assessment of Antarctic ice mass changes to date, combining 24 satellite surveys of Antarctica and involving 80 scientists from 42 worldwide organizations.

Their assessment of conditions in Antarctica is based on combined data from 24 satellite surveys and updates 2012 findings.

In its Fifth Assessment Report, the Intergovernmental Panel on Climate Change suggested that average sea level rose by 7.5 inches between 1901 and 2010.

Antarctica, which is technically classified as a desert, due to the small amount of precipitation it receives in the form of snow, is home to most of Earth's fresh water (between 60 and 90%).

While the current ice loss measured is literally a drop in the ocean compared to Antartica's catastrophic potential to raise global sea level by as much as 58 metres (190 ft) if the ice sheets were to completely melt, the apparent acceleration in the latest satellite observations is enough to have scientists duly anxious.

"Satellites have given us an fantastic, continent-wide picture of how Antarctica is changing", Pippa Whitehouse, of Durham University, said.

At the northern tip of the continent, ice shelf collapse at the Antarctic Peninsula has driven a 25 billion-ton increase in ice loss since the early 2000s.

"This does not mean that at current atmospheric carbon dioxide levels Antarctica won't contribute to sea level rise".

If the volcanoes are active, they could erupt at any moment, melting vast amounts of ice and contributing to the already worrisome rising sea levels endangering large swathes of coastal populations around the globe.

"There are many more vulnerable ice shelves in the Antarctic that, if they break up, will accelerate the processes of sea level rise", she said.

Knowing how much ice Antarctica is losing is critical to understanding how climate change will affect humanity both now and in the future, given the fact that the continent contains enough frozen water to raise sea levels by 58 meters.

These potential results rely on what is done, or not done, now about climate change.

That's adding 0.6 of a millimetre to sea levels each year.

Scientists have long known that the effects of global warming are amplified in Antarctica, causing changes that can be felt around the world. Altogether, 34,000 square kilometers (more than 13,000 square miles) of ice shelf area has been lost since the 1950s.

That's a lot of ice.

The Post also points out that East Antarctica lost around 28 billion tons of ice annually during the last five years.

The research was done by taking data from satellites that have been flying over the Antarctic region for 25 years.

Pine Island is now losing about 45 billion tons per year, and Thwaites is losing 50 billion.

According to NASA, the data for this study was gathered by over a dozen different satellites - NASA's ICESat mission, the NASA/German Aerospace Center twin GRACE satellites, the European Space Agency's Envisat and CryoSat-2 satellites, the German Aerospace Center TerraSAR-X satellite, the European Union's Sentinel-1 and Sentinel-2 satellites, the Italian Space Agency's COSMO-SkyMed satellite constellation, the Japan Aerospace Exploration Agency's Advanced Land Observatory System, and the Canadian Space Agency's RADARSAT-1 and RADARSAT-2 satellites. Of that loss, 40 percent took place from 2012 to 2017.

"The detailed record shows an acceleration, starting around 2002", said Beata Csatho, a co-author of the study, and a glaciologist at the University at Buffalo.

The geological history of the massive ice sheet - frozen both above and, in many places, below the ocean's surface - has been hard to pinpoint.

"If the political landscape of a future Antarctica is more concerned with rivalry, and how each country can get the most out of the continent and its oceans, then all protections could be overturned".

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