Man made climate change is now, without the doubt, the largest existential threat mankind has ever faced. The results of global warming are not merely hypotheses for the future – we are seeing the effects right now. Unfortunately, without rapid and comprehensive change, these catastrophic effects are just set to continue. Ice melting in Antarctica is one of these effects, and this has a knock on effect on other things – like the speed of change, and global sea levels. www.travelrows.com
What is Causing the Ice to Melt?
As greenhouse gases such as carbon dioxide continue to be released by humanity at unprecedented rates, global temperatures are rising. Rising temperatures within our atmosphere cause ice to melt more quickly. As air temperatures rise, so too to global oceanic temperatures. Ice in Antarctica is melting not just from above, but also from below, as ice comes into contact with sea waters of higher temperatures.
Antarctica Ice Mass Loss – The Facts
Between 1993 and 2016, Antarctica lost about 127 billion tons of ice. According to an international climate assessment of 2018, funded by NASA and the European Space Agency, ice losses from Antarctic ice sheets have tripled since 2012. This threefold increase is attributed to increased rates of ice melt in West Antarctica and the Antarctic Peninsula and reduced growth of the East Antarctic Ice Sheet. Before 2012, ice was lost at a steady rate of around 76 metric tonnes per year. Since 2012, ice loss per year has tripled to 219 metric tonnes.
The greatest change was experienced by West Antarctica, where ice loss rose from 53 metric tonnes per year in the 1990s to 159 metric tonnes a year since 2012. Most of this loss came from the enormous Pine Island, and Thwaites Glaciers. These are retreating rapidly due to ocean-induced melting.
What Are the Effects of Ice Melting in Antarctica?
Unfortunately, the melting ice is not only a result of global warming – but also causes more warming in turn.
Loss of Reflective Surfaces to Deflect Solar Radiation
When solar radiation hits ice, around 90% of it is reflected back out into space. As ocean and land lose their ice cover and become exposed, they absorb more solar radiation and increase global temperatures even more.
The Release of Greenhouse Gases From Thawing Soils
Global warming also thaw polar soils that have been frozen for as many as 40,000 years as the ice recedes. As they thaw, these soils release carbon that has been trapped within them. This is released into the atmosphere as the potent greenhouse gases carbon dioxide and methane. These gases cause more warming, which creates a feedback loop, thawing even more frozen soil.
Rising Sea Levels Due to Ice Melting in Antarctica
Finally, perhaps the most pressing concern when it comes to ice melting in Antarctica is rising sea level. A 2 degree C. temperature rise will cause is predicted to cause sea level to rise by between 0.30m and 0.93m by 2100. However, other research suggests that the rise could be even more profound, and the picture is complicated by other factors which could cause sea levels to rise. The collapse of the West Antarctic Ice Sheet, for example, could increase sea level by around 3.3m.
Ice loss in the Antarctic, for example, is predicted to have a disproportionate impact in the northern hemisphere. Estimates suggest that 90% of coastal areas will experience above average sea level rise.
Asia in general is likely to be the worst affected region. This is a result of hydrology, population density and asset concentration. Asia is home to 4/5 of the people expected to be flooded if there is a 3 degree C. temperature rise. However, 70% of Europe’s largest cities, at least 19 cities in Africa, and many east coast cities in America are also vulnerable to rising sea levels.
The Results of Sea Level Rise Due to Ice Melting in Antarctica
The ice losses from Antarctica alone raised global sea levels by 7.6mm between 1992 and 2017. 3mm of that rise has occurred since 2012. This may not sound like much, but Antarctica’s potential contribution to global sea level rises from its land-held ice is nearly 7.5 times greater than all the other ice sources in the world. If the Antarctic ice sheet were to melt entirely, it would be enough to raise global sea levels by 58m. Even a far lower rise would leave many of the world’s major cities under water.
* Understanding the effects of sea level rise caused by ice melting in Antarctica is easier thanks to a new simulation from the Virtual Earth System Laboratory at NASA-JPL, which allows you to ‘play with’ the various scenarios to understand what is happening, and what may happen in future. But this is more than a toy. This simulation uses real data from the Ice Sheet System Model.
* Over the next 100 years, under the most extreme warming scenario, the Amundsen Sea sector in the western portion of the continent has the largest potential sea level contribution – 297 mm of global sea level rise. But in a less extreme but more scientifically likely scenario, the Ronne Basin, to the north west of the continent, has melting ice streams like to cause around 161mm of sea level rise.
* The more we understand melting ice in Antarctica, the better we are able to understand the global patterns that will effect the future of our planet. Scientists are now better able than ever before to observe and understand ice melt and ice flow in Antarctica, and how the melting of the ice sheet will impact sea levels – not just in the short term but well into the future.
We must all wake up and face the music. If we do not act quickly to curb global warming – it may spiral completely out of our control.
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