The Cold War

News of summer heatwaves at home was sombrely received by scientists in Antarctica, where signs of climate change will have a global impact.

- Rebecca Priestley

On Cape Royds, a small promontory on Ross Island, 40km north of Scott Base, is the world’s southernmost adélie penguin colony. Here, 2300 pairs come to make nests, lay and incubate eggs, and feed their chicks – balls of grey fluff that are hard to spot against the grey volcanic rocks. The air is thick with raucous screeches and the stench of guano and regurgitated fish.

Near the colony, in small basins in the rock, are lakes rimmed with bright green or lurid orange algal mats. On either side of a small stream not much more than a trickle, tiny blobs of greeny-brown moss are rare evidence of terrestrial life.

It’s late January, and at Scott Base, TV news of a heatwave at home – in Invercargill it’s a record 32°C – is watched in sombre silence by scientists.

Much of the science supported by Antarctica New Zealand, the government agency responsible for science and environmental protection in Antarctica, is related to understanding past climates and assessing the likely effects of a warming ocean and atmosphere. The summer sunshine, trickling stream, colourful mosses and algae on Cape Royds now feel like ominous signs of things to come.

Daily weather observations, taken at Scott Base since 1957, show a slight overall warming trend but no more than might be expected from natural variability. A complex interaction between the gradually closing ozone hole and strong westerly winds seems, so far at least, to be maintaining the cold in high southern latitudes – Scott Base is at 77.8°S.

The Antarctic Peninsula, however, which extends as far north as 63°S, is one of the fastest-warming parts of the planet. Average temperatures have increased nearly 3°C in the past 50 years, resulting in several dramatic ice-shelf collapses. Progressive loss of sea ice has led to falling populations of krill and adélie penguins.