In Patagonia, more snow could prevent glaciers from melting, but only if greenhouse gas emissions are quickly curbed.

In an era of declining glaciers, southern Patagonia has managed to retain an astonishing amount of ice. But a new study published in Scientific Reports by INSTAAR postdoctoral researcher Matthias Troch suggests that this protective effect may soon reach its limit.

Before making their predictions, Troch and his collaborators looked back. They used equations that, when incorporated into NASA’s model of the ice sheet and sea level system, simulate the dynamics of glaciers over the past 6,000 years.

They found that precipitation, not temperature, was the main cause of glacier change in about 4,500 of the past 6,000 years, or 76%. In recent years, increased snowfall has protected glaciers from rising global temperatures.

These simulations were very focused. The researchers singled out three connected glaciers on the wet, ocean-facing side of the Patagonian Mountains in southern Chile. The region had clear scientific advantages.

In 2005, a team on the American research vessel Nathaniel B. Palmer collected a sediment core from a nearby fjord. Torok and his collaborators obtained the sediment cores and used them to validate and refine their model. Essentially, they had physical proof that they were on the right track.

Once they matched the numerical model to the sediment core, the researchers began asking questions about the future. In particular, they were interested in what happens to glaciers under different emission scenarios. If humans stopped burning fossil fuels today, would glaciers remain protected? What would happen if greenhouse gas emissions continued to rise?

Trok and his colleagues found that if regional warming is limited to 1.5 degrees Celsius above early-century levels, increased snowfall will continue to prevent glaciers from melting. This benchmark is achievable.

But to limit global warming to this level, humanity will need to rapidly decarbonize. If current emissions continue, temperatures in Patagonia are expected to rise to 2.8 degrees Celsius by the end of the century.

“This study highlights the need for significant emissions reductions to protect glaciers, which is essential to limit global sea level rise,” Torok said.

The researchers also modeled what would happen if there were no cuts, but the outlook wasn’t as bright. A warm, humid climate can cause rapid melting.

“This could push the glacier into a new state dominated by rain rather than snow,” Torok explained.

Torok hopes research like his will strengthen the global call to action on green policy and practice. Although much of the news about the climate is dark, there is still much harm that humans can prevent if we pursue sustainability.

“If we can limit emissions, we have the potential to protect ocean glaciers,” Torok said.

Torok also hopes the study will spark further research into ocean glaciers around the world. The conclusions drawn in southern Patagonia may be replicated in Norway, Alaska, Iceland and New Zealand. The only way to know is through further research.