New Zealand on the bow wave of global change

New Zealand on the bow wave of global change, Canterbury visiting academic says

December 18, 2014

New Zealand is on the bow wave of global change due to its southern location near the Antarctic circumpolar current, a visiting academic says.

Changes being observed in Antarctica’s atmosphere and Southern Ocean will ripple around to the globe through connections to the mid and lower latitudes affecting the weather and climate of New Zealand on the way.

A visiting University of Canterbury expert, Professor Chuck Kennicutt of Texas, who is internationally renowned for his Antarctic research says while much remains to be understood, commonly predicted changes are not only air and ocean warming but also an increase in the frequencies of atmospheric severe events such as storms, droughts and floods with more intense events, and a gradual, though relentless rise in sea level.

``As an island nation with much of its population, infrastructure, cities and ports at or near sea level, the slow rise in sea level has important ramifications for New Zealand.

``This is not only due to changes in its coastal areas but also due to the more intense storm surge and inundation during severe weather events. To understand future New Zealand weather and climate we must understand the forces and drivers that underpin the changes being seen today in the south and how these changes are communicated to rest of the Earth’s system.’’

Professor Kennicutt is a trustee of the New Zealand Antarctic Research Institute and chairs its international science panel. He was an Erskine visitor this year to the University of Canterbury’s Gateway Antarctica. The Erskine fellowship programme was established in 1963 following a generous bequest by distinguished former UC student John Erskine.

``The Antarctic includes about a tenth of the planet’s land surface, nearly 90 percent of the Earth’s ice and about 70 percent of its fresh water. Once seen as a desolate place frozen in time, Antarctica is experiencing relentless change including the loss of ice, changes in ocean circulation and recovery of atmospheric ozone that have global consequences for climate, sea level, biodiversity and society.

``Antarctica’s encircling ocean is a dominant influence on global climate and biological productivity supporting important fisheries and biodiversity as it regulates the uptake of heat and carbon dioxide by sea water. Global warming is in large part ocean warming with 90 percent of recent, excess heat being stored in the ocean.

``The Southern Ocean is also a major reservoir of greenhouse gases becoming more acidic as carbon dioxide dissolves in sea water. Cold southern waters are the first to exhibit the impacts of human actions. The Antarctic ice sheet contains about 26.5 million cubic kilometres of ice, enough to raise global sea levels by 60 metres if it returned to the ocean.

``Having been stable for several thousand years, the Antarctic ice sheet is losing ice at an accelerating pace. In the past decade a very different picture has emerged and we now know Antarctic living systems are diverse, more interconnected with the global system than was thought, and deliver important ecosystems services to the globe.

``Understanding the dynamics of Antarctica and the Southern Ocean is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth system. It is clearer than ever that the changes that are currently underway, and what happens in the Antarctic have global implications for our everyday lives,’’ Professor Kennicutt says.

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