New Zealand’s most valuable science prize, worth half a million dollars, has gone to a large team of researchers finding links between melting ice sheets in Antarctica and rising sea levels in New Zealand.
The ‘Melting ice and rising seas’ team from Victoria University of Wellington, NIWA and GNS Science is the winner of the prestigious 2019 Prime Minister’s Science Prize.
The team has found evidence that Antarctic melt due to climate change could contribute to global sea level rise of 1.4 metres by the year 2100, rather than the one metre that the Intergovernmental Panel on Climate Change (IPCC) predicted in 2013.
When the effect of land subsidence is taken into account the rise could be as much as two metres for some places in New Zealand.
And the researchers warn that a global temperature rise of 2°C will commit the planet to a long-term rise of tens of metres.
Engine room of sea level change
Starting about 15 years ago the team, which includes geologists, glaciologists, climate and social scientists, began drilling ice and sediment cores in Antarctica.
The cores have revealed how the Antarctic ice sheets have advanced and retreated as the climate has warmed and cooled over the past 20 million years.
The data have been used in ice sheet and climate models to show the impact of Antarctic melting under a warming climate.
Professor Tim Naish, from the Antarctic Research Centre at Victoria University of Wellington, says his early research in global sea levels was brought into focus when he began working in Antarctica.
“It was a chance to go to the engine room of where these sea level changes were coming from,” says Prof Naish.
Prof Naish says sediments are a wonderful archive of past climates.
‘For me it’s always been about using the rocks to understand how sea-level has changed. Or, by drilling about the Antarctic margin, [finding out] how the Antarctic ice sheet has changed through time, particularly during periods of past warmth, which are relevant to the world we’re heading towards with climate warming,” says Prof Naish.
Lessons from the past
Prof Naish says that we currently have 416 parts per million carbon dioxide in the atmosphere. The last time the world had C02 levels that high was three million years ago during the Pliocene warm period.
As a result, he says, the “West Antarctic ice sheet went away. Bits of East Antarctica went away. And global sea-level was up to 20 metres higher.”
Prof Naish has a warning. “If we leave that amount of carbon dioxide in the atmosphere then that’s the end game – that’s what we’re committing the planet to.
“The ice sheets are melting”
Dr Richard Levy says we are already seeing significant change in Antarctica caused by global warming.
“The ice sheets are melting.”
“How much they will shrink and how much sea level will go up is a big open question, and in order to answer this we use models,” says Dr Levy. “Our crystal balls in the science world are numerical models.”
“What those models are showing us are that if we keep tracking along the carbon pathway that we’re currently heading along, then the ice sheets are going to melt, they’re going to get much smaller and sea level is going to go up.”
“We need to do something,” says Dr Levy. “Stop putting carbon in the atmosphere and we should be right.”
Multi PM Science Prizes winners
Three members of the winning team this year have previously won Prime Minister’s Science Prizes in their own right. Associate Professor Rebecca Priestley and Professor James Renwick have won the Prime Minister’s Science Communication Prize, and Associate Professor Robert McKay has won the Prime Minister’s Emerging Scientist Prize.
Listen to the podcast to hear Associate Professor Nancy Bertler, Associate Professor Robert McKay, Professor Tom Naish, Dr Richard Levy and Associate Professor Nick Golledge discuss aspects of their research and its relevance to understanding sea level rise in a warming world.
Voices from Antarctica
If you would like to hear about living in and doing science in Antarctica, check out the Voices from Antarctica podcast series.
The Our Changing World Antarctic collection contains many features about Antarctic science.
2019 Prime Minister’s Science Prize winners
‘Melting ice and rising seas’ team wins 2019 Prime Minister’s Science Prize.
Laser physicist wins 2019 Prime Minister’s Emerging Scientist Prize.
Tūhoe astronomer wins 2019 Prime Minister’s Science Communication Prize.
Maths teacher wins 2019 Prime Minister’s Science Teacher’s Prize.
Young inventor wins 2019 Prime Minister’s Future Scientist Prize.