The South Pole has been getting warmer at more than three times the normal global rate, according to a new study. Research shows the changes are linked to natural weather variations as well as human behavior.
Image: picture-alliance/Xinhua/L. Shiping
Advertisement
Researchers studying temperature patterns in the South Pole found that the temperature there had risen by some 1.8 degrees Celsius in the past three decades.
The team from New Zealand's Victoria University said the rate of warming at the pole was three times the average across the rest of the Earth's surface.
In their study published in the Nature Climate Change scientific journal, scientists said warmer sea surface temperatures in the tropics appeared to have encouraged warm, moist air to travel further into Antarctica than would have been previously the case.
February was the hottest month ever recorded in Antarctica. Climate change is having a severe impact on the remote region and the population of chinstrap penguins is heavily declining, as scientists recently found out.
Image: Reuters/U. Marcelino
On an Antarctic mission
A team of scientists from two US universities set sail on an Antarctic expedition at the start of this year. During several weeks at sea, they studied the impact of climate change on the remote region. More specifically, they wanted to assess how many chinstrap penguins are left in Western Antarctica compared to the last survey of their population in the 1970s.
Image: Reuters/U. Marcelino
Tame and curious
Chinstrap penguins inhabit the islands and shores of the Southern Pacific and Antarctic Oceans. They are named after the narrow black band on the underside of their heads. Even before the scientists can hear the birds' loud, harsh calls, a pungent smell of penguin excrement indicates that a colony is nearby. Penguins have not learned to fear humans, so they mostly ignore their visitors.
Image: Reuters/U. Marcelino
Shocking results
The scientists used manual and drone surveying techniques to count the chinstrap penguins. Their findings revealed that some colonies had experienced a drop of up to more than 70%. "The declines that we've seen are definitely dramatic," Steve Forrest, a conservation biologist who was part of the expedition, told Reuters.
Image: Reuters/U. Marcelino
Food chain is declining
Chinstrap penguins feed on small fish, like krill, shrimp and squid. They can swim up to 80 kilometers (50 miles) offshore each day to obtain their food. Their tightly packed feathers work like a waterproof coat and enable them to swim in freezing waters. But climate change is decreasing the abundance of krill, which is making it harder for the birds to survive.
Image: Reuters/U. Marcelino
Reproduction challenges
Chinstraps choose to nest in particularly inaccessible and remote places. When they procreate, they build circular nests from stones and lay two eggs. Both male and female work in shifts of around 6 days each to incubate the eggs. But as global warming is causing ice sheets to melt and is driving food abundance down, reproduction is becoming less successful.
Image: Reuters/U. Marcelino
Broader implications of a changing environment
There are an estimated eight million chinstrap penguins globally, which is why there hasn't been much concern about them thus far. But in the past 50 years, their population on the Antarctic Peninsula has declined by more than half. Chinstraps aren't in imminent danger of extinction, but the decline of their populations is a stark warning about broad environmental changes taking place.
Image: Reuters/U. Marcelino
6 images1 | 6
The data showed that the South Pole — the most remote spot on Earth — was now warming at a rate of around 0.6 degrees a decade, compared with around 0.2 degrees for the rest of the planet.
The team said the research debunked a general scientific consensus that the remoteness and extreme coldness of the South Pole — compared with the rest of Antarctica — meant that it was immune to warming.
"While temperatures were known to be warming across West Antarctica and the Antarctic Peninsula during the 20th century, the South Pole was cooling," said lead scientist Kyle Clem.
"It was suspected that this part of Antarctica... might be immune to or isolated from warming. We found this is not the case anymore," he told the AFP news agency.
The increase in temperature was said to partly result from a "strong cyclonic activity" in Antarctica's Weddell Sea that was caused by higher sea surface temperatures in the western tropical Pacific Ocean.
While humans had also played a role in the increase, said Clem, it would be difficult to work out how much of the warming could be attributed to increasing greenhouse gas emissions.
The human contribution could account for around 1 degree Celsius of warming across the three decades, said Clem.
