No, Climate Change Is Not Driving Doomsday Glacier’s Decline

A CNN story implies that supposed human-caused climate change is causing the Thwaites Glacier to melt, causing sea level rise. This is false.

Data show that Antarctica has not been warming. Also, the study CNN cited itself shows the glacier has declined dramatically and recovered repeatedly in the past, all without human contribution, suggesting the present decline is part of a natural cycle. [emphasis, links added]

At approximately the size of Florida, the Thwaites Glacier is the broadest glacier on Earth. The Thwaites Glacier is often referred to as the “Doomsday Glacier,” based on the belief that a complete collapse would cause as much as two feet of sea level rise over time.

The CNN story, “The ‘Doomsday Glacier’ is rapidly melting. Scientists now have evidence for when it started and why,” discusses a new study published in the journal Proceedings of the National Academy of Sciences, which determined when the present decline began.

“By analyzing marine sediment cores extracted from beneath the ocean floor, researchers found the glacier began to significantly retreat in the 1940s, likely kicked off by a very strong El Niño event — a natural climate fluctuation which tends to have a warming impact,” reports CNN.

“Since then, the glacier has been unable to recover, which may reflect the increasing impact of human-caused global warming, according to the report.”

Although the commencement of … Thwaites’ decline may now have been determined, any prognostications about future trends for the glacier are pure speculation, unsupported by historical evidence or data about present Antarctic trends.

The underlying reports determined that the Thwaites glacier’s decline commenced in the 1940s probably prompted by a powerful El Nino event that warmed the abutting waters.

Even CNN allows that El Niños are a “natural climate fluctuation which tends to have a warming impact.” Indeed, recent years when global average temperatures have spiked have almost all coincided with El Nino events.

To be clear, from the 1940s through the 1970s global average temperatures were cooling, and CO2 concentrations were significantly lower, although beginning to increase.

What’s true for the globe as a whole, however, is not true for West Antarctica, where the Thwaites Glacier is located.

Research from 2023 shows that temperatures there have fallen nearly two degrees Celsius over the past two decades, at least.

Other research discussed at Climate Realism suggests that whatever impact the Thwaites Glacier’s decline is having on sea level rise is being mitigated by an increase in snow and ice elsewhere on the continent.

Further evidence suggesting that anthropogenic climate change has nothing to do with the Thwaites Glacier’s recent melting trend is found in the study as well.

Indeed, the study determined that the Thwaites Glacier has retreated and expanded multiple times over the millennia.

As CNN writes, the researchers involved found that “similar retreats have happened much further back in the past, the ice sheet recovered and regrew … [with] James Smith, a marine geologist at the British Antarctic Survey and a study co-author, [telling CNN] ‘Once an ice sheet retreat is set in motion it can continue for decades, even if what started it gets no worse.’ ”

The researchers and CNN bemoan the fact that the Thwaites Glacier’s decline is not reversing, but they admit that such declines have gone on for decades in the ancient past, with no help from humans.

The precipitating event, a strong El Nino, has been repeated multiple times since the 1940s, including this year, which would tend to keep conditions for melting in place.

In short, the idea that human carbon dioxide emissions are contributing to the Thwaites Glacier’s decline is pure speculation; speculation is seemingly refuted by the significant decline in surface temperature where the glacier resides, and the net gain of ice and snow on Antarctica.

The Thwaites Glacier is bucking climate trends in West Antarctica and for the continent as a whole, almost surely because of El Nino-warmed waters.

Climate change is not causing the Thwaites Glacier’s decline. Even still it would be prudent to plan for higher sea levels, regardless of trends for the Thwaites Glacier, because they are rising, although not at a historically rapid rate.

Seas always rise between ice ages, and history suggests that they will continue to rise, with fits and starts, until the next ice age commences.

Read more at Climate Realism