Science Highlights

The Future of the Antarctic Ice Sheet

A key focus of the Science Programme is melting ice, specifically, determining how fast the Antarctic ice sheet will melt and the sea level implications this will have for the rest of the planet. New Zealand researchers have produced seminal publications over the last year that provide a sobering forecast of the future, should CO2 emissions remain unchecked.

In the 2015 paper in Nature titled “The multi-millennial Antarctic commitment to future sea-level rise” Dr. Nick Golledge and colleagues present future scenarios of ice loss and sea level rise under a range of CO2 and temperature scenarios. They describe how warming of only 1.5 to 2 degrees Celsius will trigger a collapse of the Antarctic ice sheet that will be unstoppable, even if in the future warming is slowed down or stabilises. This paper brings context and urgency to decisions around “acceptable” levels of warming such as those discussed under the Paris Accord.

The last time the planet experienced global temperatures and atmospheric CO2 concentrations similar to those projected for coming centuries was during the early to mid-Miocene (23–14 million years ago). A recent paper in Proceedings of the National Academy of Science by Dr. Richard Levy and colleagues presents findings from the ANDRILL project, where sediment deposited at this time period was analysed. The paper, “Antarctic ice sheet sensitivity to atmospheric CO2 variations in the early to mid-Miocene” describes high variability of the extent of the Antarctic ice sheet during this period, and intervals where it was only a fraction of its current size. These new drill core data and associated ice sheet modelling experiments indicate that polar climate and the Antarctic ice sheet were highly sensitive to relatively small changes in atmospheric CO2 during the early to mid-Miocene.

 

Sea Ice

Despite rising global temperatures and clearly declining sea ice in the Arctic, Antarctic sea ice coverage is increasing.  New Zealand research is focussed on determining what factors influence the behaviour of sea ice around the continent. Improved understanding of these factors can inform climate models so that they will be better able to accurately predict sea ice thickness and extent.

Research led by Dr Craig Stevens from NIWA is investigating the theory that supercooled water, formed by melting of ice shelves, is causing growth in sea ice extent. They are also interested in how the meltwater influences the way that the sea ice is formed and the role that ice crystals suspended in the water column contribute to sea ice on the surface. In the 2015/16 season the team used a range of sea ice cores, temperature and salinity probes and acoustic measurements to achieve their goals.

Dr Adrian McDonald, from the University of Canterbury, and his team investigated the influence of dominant weather patterns on sea ice distribution and growth. Using ground measurements and satellite technology, it was found that sea ice in the Ross Sea is heavily influenced by the strength and persistence of westerly winds.

 

Ross Sea Ecosystem Monitoring

The Ross Sea is considered one of the last intact marine ecosystems on the planet, although there are increasing demands from fisheries and tourism. Research led by Dr Regina Eisert has focussed on how this polar marine ecosystem works, and more specifically what the effects of fishing and climate change may be. The programme has focussed on large predators including penguins, toothfish, seals and whales in the Ross Sea, of which large parts have been earmarked for a marine reserve.

The 2015/16 season involved identification of individual killer whales, which revealed that Type C (fish eating) killer whales migrate to New Zealand waters. It was also discovered that Antarctic toothfish have not disappeared from McMurdo Sound as previously thought, and they form part of the diet of Weddell Seals. Dr Steven Parker contributed to a stock assessment of Antarctic toothfish, which is yielding valuable information regarding abundance, diet, growth and maturity rates, enabling the sustainability of the fishery to be determined.

The findings of this work have direct links to policy. A number of reports have been presented to the International Whaling Commission (IWC) and to the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR), in addition to a number of publications in scientific journals.

 

Policy Relevance

There has never been a more important time for policy decisions on the future of Antarctica to be informed by the best science available on the state of Antarctic environments. Scientists and staff from Antarctica New Zealand work collaboratively to communicate scientific knowledge to decision makers and world leaders.

These are key for where scientific information is fed directly into policy, such as the Scientific Committee on Antarctic Research (SCAR) action groups, and the International Panel on Climate Change (IPCC).

The Antarctic Environments Portal bridges the gap between scientists and decision makers. It supports the protection of the Antarctic environment by bringing science knowledge to the fingertips of policy makers.

 

Scientific Advancements

Learn more about New Zealand's cutting edge Antarctic Science and Monitoring Programmes:

Antarctic Science Programme Summaries 2016/17

Antarctic Science Programme Summaries 2015/16
Antarctic Science Programme Summaries 2014/15
Antarctic Science Programme Summaries 2013/14
Antarctic Science Programme Summaries 2012/13
Antarctic Science Programme Summaries 2011/12
Antarctic Science Programme Summaries 2010/11
Antarctic Science Programme Summaries 2009/10
Antarctic Science Programme Summaries 2008/09
Antarctic Science Programme Summaries 2007/08
Antarctic Science Programme Summaries 2006/07
Antarctic Science Programme Summaries 2005/06
Antarctic Science Programme Summaries 2004/05
Antarctic Science Programme Summaries 2003/04
Antarctic Science Programme Summaries 2002/03
Antarctic Science Programme Summaries 2001/02