Expert analysis of climate change impacts on Southern Ocean

Expert analysis of climate change impacts on Southern Ocean

An international expert on the role of the ocean in the climate system will examine the impact of climate change on the critically-important Southern Ocean at a Victoria University of Wellington public lecture.

Physical oceanographer and climate scientist Dr Stephen Rintoul will give the 2015 S.T Lee Lecture in Antarctic Studies, presenting the latest evidence on how the Southern Ocean is changing. He will also review recent progress in understanding the role the Southern Ocean plays in the world’s climate, the future of the Antarctic ice sheet and rising global sea levels.

Around 93 percent of the extra heat stored by the Earth over the past 50 years has gone into the ocean, helping to slow the rate of warming at the Earth’s surface, but at the cost of ocean warming and sea level rise.

Dr Rintoul says the Southern Ocean is of particular importance because of the way in which its currents efficiently transfer water, heat and carbon between the sea surface and the deep sea.

“As a consequence, the Southern Ocean is warming, freshening and becoming more acidic. There is also growing evidence that the giant Antarctic ice sheet is thinning and retreating around its margin, where it is in contact with the warming ocean.”

Dr Rintoul, who is a Fellow at the CSIRO (Commonwealth Scientific and Industrial Research Organisation) and the Antarctic Climate and Ecosystems Cooperative Research Centre in Hobart, Tasmania, will discuss recent research on the vulnerability of the Antarctic Ice Sheet.

The research shows some parts of the West Antarctic Ice Sheet may already be on the verge of unstoppable collapse and have potential to contribute up to three metres of global sea level rise in the future, even if greenhouse gas emissions were stabilised tomorrow.

The East Antarctic Ice Sheet, which holds about 10 times as much ice as West Antarctica, has long been thought to be stable and unlikely to contribute much to future sea level rise. But a recent expedition led by Dr Rintoul—the first to reach the massive Totten Glacier— suggests the East Antarctic Ice Sheet is more sensitive to ocean warming than previously thought.

Professor Tim Naish, Director of Victoria University’s Antarctic Research Centre, says Dr Rintoul’s lecture is timely ahead of the United Nations climate change negotiations taking place in Paris later this year.

“The science is very clear on the need to limit global warming to 2C by making a new set of commitments to reduce to carbon dioxide emissions. If we miss this target then we will face some of the more severe consequences of climate change.”

Dr Rintoul has led 12 expeditions to Antarctica and coordinated the major international Southern Ocean climate research programmes conducted over the past 25 years. He was a coordinating lead author for the Fifth Assessment of the Intergovernmental Panel on Climate Change.

His scientific achievements have been recognised by many national and international awards, including the Georg Wust Prize, the Martha T. Muse Prize, the Australian Antarctic Medal and election as a Fellow of the Australian Academy of Science.

What: The S.T. Lee Lecture in Antarctic Studies 2015

Where: Hunter Council Chamber, Level 2, Hunter Building, Kelburn Campus, Victoria University of Wellington

When: 5.30pm, Tuesday 15 September

ENDS

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