Our research shows a potential new driver of global sea-level rise due to warmer waters flowing towards the EastAntarctic ice sheet.

Changing water circulation in the Southern Ocean may be compromising the stability of the ice sheet. The ice sheet is larger than the United States.

Climate change is one of the factors that cause the changes in water circulation. Warming waters and sea-level rise may harm marine life.

The urgent need to limit global warming to less than 1.5 C is underscored by our findings.

Ice sheets and climate change

Glacial ice accumulates from precipitation over land. Ice shelves are sheets of ice on the ocean.

Sea-level rise is being caused by the melting of the WestAntarctic ice sheet. It wasn't known much about its counterpart in the east.

The Aurora Subglacial Basin was the focus of our research. There is an area of frozen sea ice.

One of the biggest uncertainties in projecting sea-level rise this century is how this basin will respond to climate change. Sea levels would rise by 5.1 meters if the basin melted completely.

The basin is sensitive to ocean melting due to it's below sea level. The deeper the seawater, the lower the temperatures to freeze.

The space flight center has a scientific visualization studio.

The map shows the extent of the ice sheet.

What we found

We looked at 90 years of oceanographic observations. The ocean has warmed at a rate of up to 2 C to 3 C over the last 50 years. It takes 0.1 C to 0.4 C per decade.

Since the 1990's, the warming trend has tripled, reaching a rate of 0.2 C to 0.9 C each decade.

Climate change is linked to this warming. There is a belt of winds over the Southern Ocean. During times when the Southern Annular Mode is in a positive phase, these winds have been moving towards the South Pole.

Increased greenhouse gases in the atmosphere are to blame. In the summer, warm water comes with the westerly winds as they move closer toAntarctica.

The ice sheet was thought to be stable and protected from the ocean. That's because it's surrounded by water that's very cold.

There is a glacier in East Antarctica. The warm water replaced the denser shelf water.

The ice sheet's stability is at risk due to the movement of warm waters towards EastAntarctica.

Why this matters to marine life

Warming first occurs in the ocean's surface layers, according to previous work on the effects of climate change. The findings suggest a need to re-think impacts on marine life.

Investment in monitoring and modeling can link physical change to complex ecosystems. The effects of very rapid change, known as tipping points, that may mean the ocean changes far more quickly than marine life can adapt should be included.

Warming waters are likely to pose a high risk to the East Antarctic marine environment. Eggs are sunk to deep ocean depths in order to breed. Eggs may be affected by warmer waters. It would affect penguins, seals, and whales.

Limiting global warming below 1.5 ℃

We hope our results will lead to efforts to limit global warming. Global greenhouse gas emissions need to fall by 43 percent by the year 2030.

Warming above 1.5 C can cause sea-level rise.

If you stay below 1.5 C, the sea-level rise won't go much higher. This would make it easier for people and the environment to adapt.

Laura Herraiz Borreguero is a Physical oceanographer at the Commonwealth Scientific and Industrial Research Organisation.

The article was written by The Conversation. The original article is worth a read.