The study, published in the journal Nature Climate Change on Monday, sheds light on the most remote region on Earth. While scientists have known for years that the outer regions of Antarctica are warming up, they previously thought that the South Pole, being located deep inside it, was isolated from rising global temperatures.
“This highlights that global warming is global and is making its way to these remote places,” said Kyle Clem, postdoctoral researcher in Climate Science at the University of Wellington and lead author of the study.
Clem and his team analyzed data from the weather station at the South Pole, as well as climate models to examine warming within the Antarctic. They found that between 1
Scientists claimed that the main cause of the warming was the rising sea surface temperature thousands of miles away in the tropics. Over the past 30 years, warming in the western tropical Pacific Ocean – a region close to the equator north of Australia and Papua New Guinea – has led to an increase in the warm air transported to the South Pole.
“It’s wild. It’s the most remote place on the planet. The meaning is how extreme temperatures fluctuate and travel across the interior of the Antarctic, and the mechanisms that drive them are connected 10,000 kilometers (6,200 miles) north of the tropical Pacific continent.” Clem said.
Sea ice melting, Antarctic heat waves
While the South Pole remains below the freezing point and is likely to remain so, Clem said that the warming trend observed at the Pole is related to what we are seeing on the coast and on the Antarctic Peninsula.
Heating “starts from the coast and makes its way inland,” Clem said.
“As you approach the coast, where the warming is coming, you will start to see more impacts. As you reach that point near the freezing point you will begin to melt. Or melt the sea ice and start heating the ocean in the Weddell Sea and this affects life in that area, “he said.
The blame for the climate crisis?
Initially, scientists discovered that the South Pole was actually cooling more than a degree in the 70s and 80s, while global temperatures were rising. The team said the cool period is due to natural climate patterns that occur in cycles of 20 to 30 years.
Then the trend changed rapidly “and suddenly we have almost 2 degrees of warming at the beginning of the century,” Clem said.
The jump from 1 degree of cooling to 2 degrees of heating indicated an increase of 3 degrees.
Meanwhile, global temperatures have risen by around 1 degree Celsius (1.8 degrees Fahrenheit) compared to pre-industrial levels and the goal is to keep global average temperatures within 1.5 degrees Celsius (2.7 degrees Fahrenheit) to avoid the worst impacts of the climate crisis.
Clem said the extreme fluctuation at the South Pole suggests that natural variability was “masking” the effects of man-induced climate change.
The team found that warming was caused by natural changes in sea surface temperatures for several decades. But these natural climatic factors “acted in tandem” with or have been reinforced by global greenhouse gas emissions.
“We have natural processes that will always take place between global warming and human influence on the climate system,” said Clem. “When the two work together it is truly remarkable.”
The science behind warming
In addition to the human interference caused by greenhouse gas emissions, the researchers said there have been several natural processes working behind the scenes to heat the South Pole.
A climate phenomenon called Interdecadal Pacific Oscillation (IPO), which governs ocean temperatures in the Pacific Ocean, went from a positive phase to a negative phase in the early 21st century. This warmed the western tropical Pacific and caused more severe cyclones and storms.
All this has made the South Pole one of the fastest warming places on the planet.
Upper limits of natural variability
Since the South Pole temperature records only date back to 1957, scientists have failed to draw a definitive conclusion that warming was driven by human activity.
So they used models that simulate the Earth’s climate with greenhouse gas concentrations representative of pre-industrial times, therefore without human influence.
In the simulations, the team calculated all the possible thirty-year trends that could occur at the South Pole in those models. They found that the 1.8 C warming observed was greater than 99.9% of all possible thirty-year trends that occur without human influence.
The authors stated that while this meant that warming “lies within the upper limits of the simulated range of natural variability”, the nature of the trend was “remarkable”.
“Almost everywhere on Earth, if I had 1.8 ° C of heating for over 30 years, this would be out of scale.” Clem said.
But the result was not 100%. So there is a possibility that warming at the South Pole may have occurred only through natural processes, according to Clem: but it’s tiny.