Antarctic ice melt unstoppable without strong climate action

The Antarctica Ice Sheet contains approximately 30 million cubic kilometres of ice, which is around 1,779,359 times the volume of Sydney Harbour. We'll just let that sink in for a little bit...

It's the largest single mass of ice on earth, and most of that ice is sitting on land - which means it has the potential to contribute to sea level rise if melted.

A new study published in Nature has found that if climate change continues, driven by continued greenhouse gas emissions, an unstoppable melting process might start in Antarctica, committing us to a long-term sea level rise of over 1 metre.

You can read the full study here, but we've pulled out some key highlights for you below:

  • Unless substantial action is taken around the world to reduce human-caused greenhouse gas emissions, warming is likely to exceed 2°C above pre-industrial levels within this century.
  • With this level of warming, and the associated warming of the oceans, it is very likely that many of the coastal ice shelves (the support-beams of Antarctica) will melt.
  • Without this support, much of the Antarctic Ice Sheet will become unstable and will start a long-term sliding and melting process which will then continue regardless of whether we reduce our pollution or not.
  • If this process starts, Antarctica will be committed to contributing substantially to long-term sea level rise.
  • Under almost all the possible future pollution scenarios used in the study, the long-term sea level rise was greater than 1 metre.
  • The only scenario which did not result in such a substantial sea level rise assumed that human-caused greenhouse gas emissions were significantly reduced: including a steady reduction in carbon dioxide from 2020 onwards, capturing more carbon dioxide than we’re emitting by 2100, and a 40% reduction in methane emissions.

To prevent substantial and unstoppable long-term ice loss and sea level rise, the world MUST take major action to reduce human greenhouse gas emissions.

Image credit: United Nations via Flickr licensed under CC BY-NC-ND 2.0