“It’s wild. This is the most remote place on the planet. Significance is how extreme temperatures swing and shift over Antarctica’s interior, and the mechanism that moves them is linked 10,000 kilometers (6,200 miles) north of the continent in the tropical Pacific,” Clem said.

Melting sea ice, Antarctic heat wave

While the South Pole remains below freezing and tends to stay that way, Clem says that the warming trends seen at the Pole are related to what we see on the coast and the Antarctic Peninsula.

Warming “begins at the beach and works inland,” Clem said.

“As you move closer to the coast, where warming comes in, you will start to see more impact. When you reach a point near freezing you start to melt. Or you melt sea ice and you start to warm the ocean in the Weddell Sea and it affects life in that area, “he said.

Is the climate crisis to blame?

Initially, scientists discovered the South Pole actually cooled more than one degree during the 1970s and 1980s, while global temperatures were rising. The team said the cold period is to a natural climate pattern that occurs in cycles of 20 to 30 years.

Then the trend reverses rapidly “and suddenly we have almost 2 degrees of warming at the turn of the century,” Clem said.

A jump from 1 degree cooling to 2 degrees heating indicates an increase of 3 degrees.

Meanwhile, global temperatures have risen about 1 degree Celsius (1.8 degrees Fahrenheit) above pre-industrial levels and the aim is to keep global average temperatures within 1.5 degrees Celsius (2.7 degrees Fahrenheit) to prevent the worst effects of the climate crisis.

Clem said extreme fluctuations in the South Pole indicate that natural variability “mask” the effects of human-induced climate change.

The team found that warming was caused by natural variations in sea surface temperatures for decades. But these natural climate drivers “act together” with, or are reinforced by, global greenhouse gas emissions.

“We have a natural process that will always occur in the midst of global warming and human influence on the climate system,” Clem said. “When the two work together, it is extraordinary.”

The science behind heating

In addition to human intervention from greenhouse gas emissions, the researchers say there are several natural processes that work behind the scenes to warm the South Pole.

A climate phenomenon called the Interdecadal Pacific Oscillation (IPO), which regulates ocean temperatures in the Pacific Ocean, shifts from a positive to a negative phase at the turn of the 21st century. It warms the western tropical Pacific, and causes more severe storms and storms.

All of that makes the South Pole one of the fastest warming places on the planet.

The upper limit of natural variability

Since the temperature record of the South Pole only returned to 1957, scientists cannot draw definitive conclusions that warming was driven by human activity.

So they used a model that simulates Earth’s climate with concentrations of greenhouse gases that represent pre-industrial times – without human influence.

In the simulation, the team calculates all 30-year trends that might occur in the South Pole in the models. They found that the observed warming of 1.8 C was higher than 99.9% of all 30-year trends that might occur without human influence.

The authors say that while this means warming “lies in the upper limit of the range of natural variability that is simulated” the nature of the trend is “extraordinary.”

“Almost everywhere else on Earth, if you have 1.8C warming for more than 30 years, this will be off the charts.” Clem said.

But the results are not 100%. So it is possible that warming at the South Pole can occur only through natural processes, according to Clem – but it is small.