Over the last forty years, rising temperatures have accelerated ice loss from the ice sheets and glaciers that cover around 10% of the Earth’s land area. Due to more extreme warming above the Arctic circle, the Greenland Ice Sheet melting rate has drastically accelerated, which is expected to continue into the future. 

The Greenland Ice Sheet holds enough water to raise average global sea levels by 7.4 metres. The accelerated ice loss observed in recent decades can be attributed to atmospheric and oceanic warming. The average winter near-surface air temperature has risen 2.8°C over the 100-year period from 1911 to 2012. 

Northern Hemisphere temperature anomalies

Figure 1. Temperature anomalies above 64°N latitude, from 1880 to 2019 (data: NASA GISS).

Since 1978, Arctic sea ice extent has visibly decreased for all months of the year, with a reduction of around 10 to 12% per decade in the month of September (yearly low).

Greenland Ice Sheet September 1980-2012

Figure 2. Comparison of sea ice cover in Greenland between September 1980 and September 2012 (data: Copernicus data hub).

From 2006 to 2015, the Greenland ice sheet lost ice mass at an average rate of around 270 gigatons per year. To put that into perspective:

Gigatonne perspective

As a result, mean sea levels have risen by  10.8 ± 0.9mm from 1992 to 2008.

What are the Potential Impacts?

So far we have just considered Greenland’s ice sheet. This, combined with a rapid breakup of West Antarctic ice sheets could result in up to 5m of sea level rise by the end of the century. 

This would disproportionately affect developing countries, particularly Vietnam, Egypt and the Bahamas. Places like West Africa are already feeling the bite.

As a final bombshell, if we ignore ice sheet instability then it is estimated that sea levels will still rise by 50-70cm resulting in the forced displacement of up to 200 million people, 70% of which will come from just 8 countries in Asia.

 

Acknowledgements

Big thanks to all the authors and people behind the referenced source and those backing the fight for our planet Earth.

Article written by Steven Vuong and Owen Mulhern.

You might also like: The Cost of Natural Disasters.

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