Antarctica is thawing faster than expected, pushing up world sea levels by almost a centimetre since the early 1990s, an international team of scientists said today.
The sea-level rise puts coastal areas at risk.
Antarctica has enough ice to raise seas by 58m if it ever all melted.
The frozen continent lost almost three trillion tonnes of ice between 1992 and 2017, the 84 scientists said in what they called the most complete overview of Antarctic ice so far.
The thaw, tracked by information from satellites and other measurements, contributed* 0.76cm to sea level rise since 1992, they wrote in the journal Nature.
And the ice losses quickened to 219 billion tonnes a year since 2012, from 76 billion previously*. “The sharp increase … is a big surprise,” said professor Andrew Shepherd of the University of Leeds and a leader of the report.
Most ice was being lost from West Antarctica and the Antarctic Peninsula, where warmer ocean water is melting floating ice shelves at the end of glaciers, allowing ice stored on land to slide faster toward the sea, the study said.
A single millimetre of global sea level rise is equal to 360 billion tonnes of melted ice, or an imaginary gigantic ice cube with sides about 7km long.
Overall, world sea levels have risen about 20cm in the past 100 years, caused mainly by water already in the oceans expanding as it warms along with a thaw of glaciers elsewhere in the world.
A major United Nations* assessment in 2014 said seas could rise this century by between 30cm to almost 1m.
Prof Shepherd said just the Antarctic thawing alone is now on track to raise world sea levels by about 15cm by 2100, above most past predictions.
Such a rise sounds small but would make coastal floods during storms at high tides more damaging, he said. Sea level rise is a threat to coastal cities such as New York and Shanghai and low-lying nations from the Pacific Ocean to the Netherlands.
“We’re watching these reports closely,” said Michiel van den Broeke, professor of Polar Meteorology at Utrecht University in the Netherlands, saying they were the guide for defending the Netherlands’ coast.
Under the 2015 Paris Climate Agreement, almost 200 governments set a goal of phasing out* fossil fuels* this century to limit warming. Australia is part of this agreement. US President Donald Trump plans to pull out of the agreement and to focus instead on US jobs and coal, which is a type of fossil fuel.
Chris Rapley, a professor of climate science at University College London, who was not involved in the study, wrote in a comment that he had suggested in 2005 that a “slumbering* giant (of ice in Antarctica) seemed to be awakening. This paper suggests it is stretching its limbs.”
- contributed: added
- previously: before now
- United Nations: international organisation that helps countries talk and agree on important world topics
- phasing out: slowing getting rid of
- fossils fuels: fuels such as coal, gas and oil that come out of the ground
- slumbering: sleeping
LISTEN TO TODAY’S STORY
- If all the ice in Antarctica melted, how much higher would the sea level be?
- Where around Antarctic is the most ice being lost and why?
- A single millimetre of sea level rise is the same as what size ice block melting?
- Give some examples of places where sea-level rise would have a big impact.
- What is the goal of the Paris Climate Agreement Australia is part of?
1. Impact of melting ice
If all the ice in Antarctica melted what effect would this have on the environment and the population?
Create a flow chart of how ice melting will impact the world as we know it. An example to help get you started …
Antarctic ice melts => Sea levels rise => Some land is covered by water =>
=> Penguins in Antarctica lose habitat =>
Your flow chart may have many branches where there is more than one effect.
Time: Allow 30 minutes
Curriculum links: English, Science, Mathematics
Many governments are trying to reduce global warming, which will hopefully reduce the Antarctic ice melting, by agreeing to phase out the use of fossil fuels.
200 governments participating in the 2015 Paris Climate Agreement is fantastic but it would be better if all countries (particularly big countries) agreed to the phasing out of the use of fossil fuel.
Can you convince governments who are yet to sign to help save Antarctica by reducing global warming?
Write a poem or a song that highlights why it is important to reduce the use of fossil fuels. Your song or poem might be a sad tale of what the world will be like if the ice melting continues or it might be a more upbeat message highlighting why we should reduce our use of fossil fuels.
Practise your song/poem and when you are happy with it present it to your class.
Time: Allow 45 minutes
Curriculum links: English, Science, The Arts — Music
With a partner see if you can you identify all the doing words/verbs in this text. Highlight them in yellow and then make a list of them all down your page. Now see if you and your partner can come up with a synonym for the chosen verb. Make sure it still makes sense in the context it was taken from.
Try to replace some of the original verbs with your synonyms and discuss if any are better and why.
QUESTION: What can children do to help slow global warming?
Use full sentences to explain your answers.