Antarctica biodiversity faces devastation without rapid emission reductions

Researchers have warned that without drastic and immediate action, Antarctica’s fragile environments “may well be subject to considerable stress and damage in future years and decades”.

The study, published in Frontiers in Environmental Science, reviewed evidence of extreme events in Antarctica and the Southern Ocean, including weather, sea ice, ocean temperatures, glacier and ice shelf systems, and biodiversity on land and sea.

“Antarctic change has global implications,” said lead author Professor Martin Siegert, from the University of Exeter. “Reducing greenhouse gas emissions to net zero is our best hope of preserving Antarctica, and this must matter to every country – and individual – on the planet.”

He also warned that rapid changes in Antarctica could place many countries in breach of an international treaty. The Antarctic Treaty, which contains a pledge to preserve its fragile environment, includes signatories such as the UK, US, India and China.

“Nations must understand that by continuing to explore, extract and burn fossil fuels anywhere in the world, the environment of Antarctica will become ever more affected in ways inconsistent with their pledge,” Siegert added.

The world’s largest recorded heatwave (38.5°C above average) occurred in East Antarctica in 2022, and winter sea ice formation is today the lowest on record.

Extreme events can also affect biodiversity. For example, high temperatures have been linked to years with lower krill numbers, leading to breeding failures of krill-reliant predators – evidenced by many dead fur seal pups on beaches.

Co-author Professor Anna Hogg, from the University of Leeds, said: “Our results show that while extreme events are known to impact the globe through heavy rainfall and flooding, heatwaves and wildfires, such as those seen in Europe this summer, they also impact the remote polar regions.

“Antarctic glaciers, sea ice and natural ecosystems are all impacted by extreme events. Therefore it is essential that international treaties and policy are implemented in order to protect these beautiful but delicate regions.”

The retreat of Antarctic sea ice will make new areas accessible by ships, but the researchers said that careful management will be required to protect vulnerable sites.

The European Space Agency and European Commission Copernicus Sentinel satellites are “an essential tool” for regular monitoring of the whole Antarctic region and Southern Ocean. This data can be used to measure ice speed, sea ice thickness and ice loss at exceptionally fine resolution.

In March, another team calculated that Antarctica had lost 3,331 billion tonnes of ice between 1996 and 2021. Changes in ocean temperature and currents are thought to have been the most important drivers in the loss of ice.