Can melting in Antarctica buy us some time?

A strong sense of climate hope keeps me looking for good news from our natural world.

Ice melting in Antarctica is not good news. But, it might delay the warming of the oceans, and hence the Earth. That’s at least a tiny bit positive.

It is actually possible. Research on this effect is limited. Best case is that the cold water from the melted ice will reduce the ocean temperature with as much as 0.4 degrees celsius. This effect may give us another 10 years before we reach 1.5-2.0 degrees.

But, it can also lead to less precipitation in the Southern hemisphere around Equator. Northern Australia, parts of Indonesia, Papua New Guinea, Africa and South America. We all know what may entail. The drought in Australia caused some of the biggest wild fires in history.

Scientists say that even if this is right, we know all to little to comfortably “add” 10 years. The effect of the melting is only relevant at the maximum CO2-emission scenario. If we emit less, this effect is less. The Northern hemisphere would get more precipitation. And if the melting of the Greenland ice sheet is included we will get more rain both North and South. The study published in Nature two years ago does not include melting of the Greenland ice sheet.

What happens in Antarctica doesn’t stay in Antarctica

What is certain is that the ice sheets in Antarctica is melting and it is happening fast. We are talking enormous amounts of water. It is also beyond doubt that when the cold water enters the ocean it will affect the temperatur, ocean currents and the climate.

So, how much water is it?

Antarctica is the fifth largest continent covering 14.2 million square kilometers. This is twice the area of Australia.

Get to know Thwaites

BBC visited what is known as the “doomsday glacier”, the “most dangerous” and “most important”. Thwaites is the size of England. The run off from this glacier represents 4 per cent of today’s sea level rise. Should the entire glacier melt, the world oceans will rise with more than half a meter.

A 50 million dollar research project led by American and British scientists will spend the next five years to understand more of the inner life of Thwaites. The glacier is located 1.600 kilometers from the nearest research station. Only four people have been there and they were all part of this project.

The ice in Antarctica holds 90 per cent of all Earth’s fresh water. 10 per cent is where Thwaites is, in the West. The Eastern ice that lies higher above the sea is 1.5 kilometers thick and has been there for millions of years. The Western ice however is partly below the sea. Changes in the ocean temperature therefore directly affects the ice.

Last year NASA discovered a huge cavity of 57 square kilometers wide and 300 meters deep between the ocean bed and the ice. The scientists were expecting that ice no longer reached the sea bed. Such cavities means water get under the ice and melts it from underneath. The more water and heat under the ice, the faster it melts.

They did not expect the cavity to be this big. The last 3 years 14 billion tonnes of ice have disapeared between the ice and the sea bed.

The cryosphere

The IPCC cryosphere report published last year gives us an idea how the frozen part of the Earth is doing: Glaciers, ice caps, ice sheets, frozen ground, permafrost and snow. It was not good news.

A little digresion first.

Investments in coal-fired power has dropped with 75 per cent last three years. In 2015 investments reached 88 gigawatt. Last year this figure was down to 22.

There are more coal-fired power stations closing than opening. We will see less of them if this trend continues which is the first time in history. Investors are going for green projects. The return on fossile fuel investments decrease.

What happens with the Earth’s ice?

The report says in the summary that:

“Around 10% of Earth’s land area is covered by glaciers or ice sheets. The ocean and cryosphere support unique habitats, and are interconnected with other components of the climate system through global exchange of water, energy and carbon. The projected responses of the ocean and cryosphere to past and current human-induced greenhouse gas emissions and ongoing global warming include climate feedbacks, changes over decades to millennia that cannot be avoided, thresholds of abrupt change, and irreversibility.”

“Over the last decades, global warming has led to widespread shrinking of the cryosphere, with mass loss from ice sheets and glaciers, reductions in snow cover and Arctic sea ice extent and thickness, and increased permafrost temperature.”

The cryosphere shrimps. Threatened species in high mountains and the poles may be extinct. Access to fresh water may be critical.

The oceans are heated from the surface and down. Heating of the oceans now occur twice as fast as it did 25 years ago. Marine heat waves are more powerful and have doubled in frequency since 1982. Less oxygen, more acid, changes in ocean currents circulation and sea level rise.

When the permafrost melts it also emits CO2 since it holds twice as much CO2 as the atmosphere.

Bilde: Getty Images. Chris Larsen/UAF/NASA