Worst-Case Climate Scenario Would Irreversibly Damage Antarctica, Scientists Warn

As carbon emissions continue to raise the Earth’s temperature further, Antarctica is bearing the brunt of its effects. This frozen continent is warming almost twice as fast as the rest of the world, threatening its ecosystems, raising sea levels and destabilizing global food chains.

Humanity’s choices over the next decade will determine the fate of Antarctica, according to a study published Friday in the journal Frontiers in Environmental Science. The researchers, led by Newcastle University glaciology professor Bethan Davies, modeled the best- and worst-case scenarios for the Antarctic Peninsula, the hottest part of the continent. To avoid the worst consequences, the world needs to move towards net-zero emissions as quickly as possible.

“It’s definitely possible — we can definitely do it,” Davis told Gizmodo. “It means thinking logically about how we power our countries, how we heat our homes, [making] Policy decisions about how we live our lifestyle. “It’s all manageable and doable.”

Antarctica’s dangerous future

For their study, Davis and colleagues analyzed CMIP6 climate data. CMIP6 is a coordinated set of standardized simulations from dozens of climate models that allows scientists to predict how Earth systems will respond to different rates of greenhouse gas emissions while reducing uncertainty.

The study considers three different scenarios: low emissions, medium-high emissions, and very high emissions. The low-emissions (or best-case) scenario would result in no more than 3.24 °F (1.8 °C) global warming above pre-industrial levels by 2100.

This future will protect the Antarctic Peninsula from the worst environmental damage and the most serious global consequences of that damage. Winter sea ice extent would be only slightly smaller than today, and the peninsula’s contribution to sea level rise would be only a few millimeters. The glaciers and their supporting ice shelves will remain largely intact.

Unfortunately, humanity is not currently following that path. The world is on track for a moderate to moderate-high emissions future in which global average temperatures will rise 6.5 degrees Fahrenheit (3.6 degrees Celsius) above pre-industrial levels by 2100.

Under that scenario, temperatures on the Antarctic Peninsula would be 6.12 degrees Fahrenheit (3.4 degrees Celsius) warmer than today. About 19 days per year will be above 32 °F (0 °C), and more precipitation will occur as rain than snow.

Rising ocean temperatures and shallowing will also accelerate the retreat of glaciers. The peninsula will also experience more extreme weather events, and native species – such as Adélie penguins – will be displaced due to inhospitable climatic conditions.

“The Adélie penguin is a hardy little animal, but it can’t tolerate its babies getting wet,” Davis said. “What happens when it rains on the Antarctic Peninsula is you can lose the entire breeding colony – you can lose all the chicks.” He said researchers are already seeing the peninsula’s Adélie population contract as other penguin species move in.

Then there’s the very high emissions scenario, in which global average temperatures rise about 8 degrees Fahrenheit (4.4 degrees Celsius) above pre-industrial levels by 2100. This would be devastating to the Antarctic Peninsula, causing ice shelf collapse, large sea ice loss, more frequent and severe extreme weather events, and dramatic declines in native species.

The damage will be irreversible, Davis said. While the world is not currently headed toward that worst-case scenario, it shows what could happen if humanity overshoots emissions targets and fails to curb emissions in the coming decades.

“The risk is that even if we bury all the carbon in the ground and come up with a magical technology to do it, we’ve already passed the major tipping points on the Antarctic ice sheet, as well as other tipping points globally,” Davis said.

no time like the present

For researchers like Davis who conduct fieldwork on the Antarctic Peninsula, the effects of global warming are already readily apparent. He has seen snowdrifts filled with meltwater puddles and rain storms even during the dark winter months. In some cases, he said, researchers have had to abandon field sites because melting has made them too dangerous to access.

“We can think of the Antarctic Peninsula in particular as that canary in the coal mine,” Davis said. “This is the hottest part of Antarctica [and] That’s where you’re going to see change happen first.” “What happens there will change the entire continent and the world,” he said.

The main takeaway from his team’s findings is that it’s not too late to change course. If the world acts quickly to curb carbon emissions, Antarctica’s future could look very different from the most likely scenario outlined in this study. Humanity’s choices over the next decade will be critical to stabilizing this vital region.