New Zealand officials have warned that access to Antarctica is becoming more precarious as warming temperatures damaged the ice runways, making it impossible to land New Zealand Air Force planes.

Wheeled aircraft were unable to land at the Pegasus Runway for two months this summer, and New Zealand had to depend on ski-equipped US planes to get scientists and other workers to and from Scott Base.

New Zealand Antarctic Institute chief executive Lou Sanson told a select committee at Parliament that temperatures had been 1.5C above average at Ross Island, the warmest on record.

"It's quite a change. It may just be a blip or it may be something more of a trend, we just don't know at this stage. But we are thinking we might have to revert back to how we operated in the 1980s, with no jets in the period December to January."


A dust storm had also eaten away at the runway, worsening conditions for landings.

Asked by MPs how much it would cost to fit a New Zealand Hercules C-130 with skis, Mr Sanson said it was a staggering $250 million per plane.

"It's very expensive. You've virtually got to build the plane on top of the skis."

The United States' National Science Foundation was the only country to have fixed skis to a Hercules, and used seven of the aircraft on the ice.

In the middle of the summer, when the ice became "sticky", US planes required "missile-assisted" takeoff. Sidewinder rockets were fixed to the planes at a cost of $200,000 per takeoff.

Mr Sanson said Australia and Russia also had sea-ice runways at sea level on the continent, which were also threatened by the warming trend.

Officials said this summer was the fourth consecutive year of above-average warmth, after a decade of cooling.

Mr Sanson said that while the West Antarctic was rapidly warming, the East Antarctic was cooling. Ross Island, where Scott Base and the US' McMurdo Base were situated, was halfway in between the two ice sheets and was warming gradually.


Institute chair Rob Fenwick said that while the warming on the surface of the ice was well-understood, the effect of warm ocean currents under the sea ice was not as well known.

Investigating this phenomenon was crucial to understanding the impact of a warming world, and sea level rise, on New Zealand.