How to save Antarctica (and the rest of Earth too)

June 13, 2018, Imperial College London
Illustration of the negative effects under the worst-case scenario. Credit: Stephen Rintoul et al./Nature

Decisions made in the next decade will determine whether Antarctica suffers dramatic changes that contribute to a metre of global sea level rise.

In a new study, scientists argue that time is running out to save this unique ecosystem, and that if the right decisions are not made to preserve Antarctica in the next ten years then the consequences will be felt around the world.

Their results, published today in Nature, assess the state of Antarctica in 2070 under two scenarios, which represent the opposite extremes of action and inaction on and environmental protection.

Antarctica is affected by many global changes, but in turn it also affects the global environment. For example, one of the largest uncertainties in future sea-level rise predictions is how the Antarctic ice sheet reacts to human-induced global warming.

The Southern Ocean around Antarctica also absorbs a large amount of carbon dioxide (CO2) from the atmosphere, slowing the rate of climate change. However, it can only absorb so much CO2, and absorbing excess amounts increases the acidity of the water, harming marine life.

Predicting the future

To see what the future might hold, an international team of researchers, including scientists at Imperial College London, has predicted what would happen under two future scenarios. Firstly, if emissions rise unabated and regulation in Antarctica fails to keep up with changes; and secondly if emissions are significantly reduced through regulations informed by research.

The authors argue that which scenario plays out depends significantly on choices made over the next decade, on both climate-change mitigation plans and on environmental regulation. For example, there is currently a moratorium on mining in Antarctica, but as global population rises this accord could be threatened.

Co-author Professor Martin Siegert, from the Grantham Institute—Climate Change and the Environment at Imperial, said: "Some of the changes Antarctica will face are already irreversible, such as the loss of some ice shelves, but there is a lot we can prevent or reverse.

"To avoid the worst impacts, we will need strong international cooperation and effective regulation backed by rigorous science. This will rely on governments recognising that Antarctica is intimately coupled to the rest of the Earth system, and damage there will cause problems everywhere."

Lead author Dr. Steve Rintoul, of the Centre for Southern Hemisphere Oceans Research and Antarctic Climate and Ecosystems Cooperative Research Centre in Australia, said: "Greenhouse gas emissions must start decreasing in the coming decade to have a realistic prospect of following the low emissions narrative and so avoid global impacts associated with change in Antarctica, such as substantial sea level rise."

Two extremes: on the road to collapse or impacts minimised

Under the high emissions and low regulations narrative, Antarctica and the Southern Ocean undergo widespread and rapid change, with global consequences.

  • By 2070, warming of the ocean and atmosphere has caused dramatic loss of major ice shelves, leading to increased loss of grounded ice from the Antarctic Ice Sheet and an acceleration in rise.
  • Environmental changes including warming, sea ice retreat and ocean acidification have altered marine ecosystems.
  • Unrestricted growth in human use of Antarctica has degraded the environment and introduced invasive pests.

Under the low emissions and tight regulations narrative, reduction of greenhouse gas emissions and implementation of effective policy helps to minimise change in Antarctica, which in 2070 looks much like it did in the early decades of the century.

  • Antarctica's ice shelves have remained intact, slowing loss of ice from the ice sheet and reducing the threat of sea level rise.
  • Ocean acidification has not worsened and Antarctic ecosystems have remained intact.
  • Human pressures on the Antarctic are managed by an increasingly collaborative and effective governance regime.
Comparison of the effects under best and worst case scenarios. Credit: Stephen Rintoul et al./Nature

Professor Siegert said: "If the political landscape of a future Antarctica is more concerned with rivalry, and how each country can get the most out of the continent and its oceans, then all protections could be overturned.

"However, if we recognise the importance of Antarctica in the global environment, then there is the potential for international co-operation that uses evidence to enact changes that avoid 'tipping points' - boundaries that once crossed, would cause runaway change, such as the collapse of the West Antarctic Ice Sheet."

More detail on the impacts: environmental

Under the worst-case scenario of high greenhouse gas emissions and low or ineffective regulations, the global air temperature would rise nearly 5C above 1850 levels, whereas under the best-case scenario of low emissions and tight regulations, it would be kept under the target of 2C warming.

In the worst-case scenario, floating ice shelves that hold back ice on land would collapse, enhancing flow of ice from land to the sea. Antarctica would contribute more than 25 cm to a total global sea level rise of more than a metre. This could lead eventually to the collapse of the entire West Antarctic Ice Sheet, and around 3.5 m of .

Currently, ice loss at the margins of Antarctica is compensated by increased accumulation of ice through snowfall at the centre of the continent. By 2070, however, this balance would no longer be possible, and the continent as a whole would be losing ice mass.

The extent of summer sea ice would also reduce by 50%. This, combined with ice shelf collapses and grounded ice losses, would lead to a freshening of the local ocean surface, which would change ocean currents.

The ocean itself would also warm up to 2C from today's levels, reducing its ability to absorb CO2 and causing global warming to occur faster. The acidity of the oceans would also reach a point where the shells of certain sea creatures are unable to form properly.

In contrast, under the best-case scenario, Antarctica's contribution to sea level would only be about 6cm in a global rise of around half a metre, due to instabilities in the West Antarctic Ice Sheet that have been irreversible since 2010.

However, many of the other impacts in the region would be significantly less, and in some cases reversed. The ocean would not experience significant freshening because of reduced sea ice loss and ice shelf breakup, leaving circulation patterns intact.

The ocean would also warm less, by only around 0.7C, meaning it would retain its ability to absorb CO2 and the acidity would not be at harmful levels.

More detail on the impacts: human

As well as the physical changes to Antarctica, the analysis also looked at the impacts on ecosystems and direct human impacts, such as mining and tourism. These factors depend strongly on how much international agreement and cooperation there is, particularly in creating and enforcing well-informed regulations.

The authors say that this means research programs need to be supported to make evidence-based decisions on the best way forward. If these are maintained into 2070, and the international community acts together on the recommendations, then worst impacts can be avoided.

For example, without strict limits on fishing, stocks of regularly caught species will decline dramatically. As a result, new species will be fished, and these will also be diminished quickly if regulation does not catch up. There will also be knock-on effects on the populations of seabirds and mammals, changing the entire structure of the ecosystem.

There are resources in Antarctica that could be mined, such as coal and iron ore, but current international agreements forbid their extraction. However, by 2070 governments with logistical presence and capability on the continent could be more interested in dividing up the resources, rather than saving the entire environment.

With less ice on land and sea, tourism could also reach unsustainable levels—for example with the introduction of permanent hotels. Tourists will bring and spread new species if there is not appropriate control, and the analysis predicts that some of the world's most invasive species would take hold by 2070 in this case.

Explore further: Alarming projections for polar ice sheets

More information: Choosing the future of Antarctica, Nature, DOI: 10.1038/s41586-018-0173-4 , https://www.nature.com/articles/s41586-018-0179-y

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23 comments

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Dug
2.3 / 5 (12) Jun 13, 2018
This is not a study, but rather the results of projected model based on the assumptions inserted in to the model.
jonesdave
3.6 / 5 (9) Jun 13, 2018
This is not a study, but rather the results of projected model based on the assumptions inserted in to the model.


Fine, dear. What 'assumptions' should they have put into the model? Those supplied by Texaco, perhaps? Shell Oil? Go on, dear, give us a clue.
Dug
2.7 / 5 (7) Jun 13, 2018
This is not a "study," but rather the results of a projected model based on the assumptions input in to the model. In any case, nothing that we will do in the next ten years - short of creating a planetary nuclear winter will slow up the CO2 increases and its heat impacts which already in process - or the continuation of global human population growth and its additional CO2 increase impacts. Where are those solutions mentioned that would actually reduce CO2 levels or change current climate change effecting Antarctica - or anywhere else?
Dug
2.5 / 5 (8) Jun 13, 2018
A "study" makes observations and conclusions on actual data. Models project future scenarios based on limited inputs - right or wrong. Projections generally have probabilities as to their accuracy - though no such limits are mentioned here - which is not unusual in climate modeling, but badly needed. Most if not all climate models to date have been wrong. Not that the intent is not genuine or that they are not using the best information available, or that they are not needed, but climate is a nascent science and we should temper our expectations regarding the accuracy of these early projections - and our emotions over its early results. Given that basic math and chemistry says that existing CO2 levels will take several centuries to dissipate, it's hard to see what we can do in the next decade to lower them.
jonesdave
2.6 / 5 (5) Jun 13, 2018
Whoa, boy. Not disagreeing with you there. Just figured you were another of the petroleum lackeys, dissing another climate change model. I would have to read the paper to discern what sort of model they used (and I will do), but failing to predict future change is not an excuse. Please do tell us where this data is available, if these people don't have access to it? Or should we not be modelling such things?
antigoracle
2.2 / 5 (10) Jun 13, 2018
More pathological lies from the AGW Cult and their Pathological "science". While the East Antarctic gains ice, the only place the Cult can find GloBull warming is the West Antarctic where there is extensive geothermal activity. That's the magic of their evil CO2.
rrwillsj
1.7 / 5 (6) Jun 13, 2018
The denier shills are are the wether with a bell around it;s neck. To lead the sheeple into the abattoir. As the sheeple blindly lined up for the boltgun to the head. The wether will be led away to rest. Contentedly to chew it's cud. Smugly satisfied that it had led another herd of the credulous to the slaughter.
jonesdave
3.9 / 5 (7) Jun 13, 2018
More pathological lies from the AGW Cult and their Pathological "science". While the East Antarctic gains ice, the only place the Cult can find GloBull warming is the West Antarctic where there is extensive geothermal activity. That's the magic of their evil CO2.


Dick. Science not your thing, is it dear?
Thorium Boy
2.7 / 5 (7) Jun 13, 2018
Why do they only talk about the so-called melting end of Antarctica while ignoring snow and ice increases in other areas?
Shootist
2.5 / 5 (8) Jun 14, 2018
oh christ on a stick

if you're worried tell algore and the rest of your idiot leaders to stop flying charter jets
If you're worried plant some trees
If you're worried paint all artificial sky facing surfaces white.

That ought to keep you out of mischief for a while. Come back when you're bored.
Shootist
2.5 / 5 (8) Jun 14, 2018
More pathological lies from the AGW Cult and their Pathological "science". While the East Antarctic gains ice, the only place the Cult can find GloBull warming is the West Antarctic where there is extensive geothermal activity. That's the magic of their evil CO2.


Dick. Science not your thing, is it dear?


Just explain the truth. The climate changes. That's what chaotic systems do.
greenonions1
3.7 / 5 (3) Jun 14, 2018
Dug
Most if not all climate models to date have been wrong
What do you base that evaluation on Dug? The models have predicted that global temperatures would increase - and they have. Same with sea level rise. Have you spent a life time working with climate models? I have not - but then I am not the one making grand proclamations. If you google the accuracy of climate models - you can spend a great deal of time reading sites that claim the models have been validated, and others that say they are wrong. Can you show us any science - that contradicts the assertion that global temperatures are rising, ice sheets/glaciers are melting, oceans are rising? These are all the predictions of climate models, and also reality on the ground.
barakn
4.2 / 5 (5) Jun 14, 2018
Just explain the truth. The climate changes. That's what chaotic systems do.

Your argument has been simplified to the point of meaninglessness. Many chaotic systems have what are known as attractors, states that a system will tend to stay near even as they constantly change. It's what allows me to predict it will not snow in Fort Worth in July.
rrwillsj
2.3 / 5 (3) Jun 14, 2018
TB, since you have failed to stay awake in your classes. This is what? The third time you are flunking sixth grade?
Put down the comicbooks and pay attention.
There is suppose to be ice and snow at the Poles. When the Polar regions are warm enough for the ice and snow to melt away? That is a "Bad Thing."
Where you live. If the weather is a balmy100°+ at 90%+ humidity for three months in a row of running your AC full blast 24/7? Your utility bills will definitely be a "Bad Thing'.
Followed by several months of erratic weather. Swinging back and forth from freezing cold to blistering heat from day to day.
Choose one. Hurricanes or tornadoes. Oh wait, you don't get a choice. You're getting both!
As icing on your mud-pie? All that fun will be followed by several months of Russian Winter. Hope you got a strong back for all the snow you'll get to shovel. To quote your fuehrer Putin "Трахайте их! Если они не могут шутить!"
tblakely1357
1 / 5 (3) Jun 14, 2018
Doom because of an environmental Armageddon is always 10-20 years in the future and the solution is always the same.... massive transfer of wealth to unaccountable international elites, diminution of prols lifestyle and the curtailment of human rights.
PTTG
5 / 5 (4) Jun 14, 2018
I really wish this website had active mods.
rodkeh
1 / 5 (3) Jun 14, 2018
I can't imagine a bigger pile of horse sh*t!
Even if the ice continues to melt at the same rate for the next 100 years, the effects on sea level will still be imperceptible to human eye.
This is just more baseless fear mongering predicted on junk science and an imaginary threat!
gkam
2.3 / 5 (3) Jun 14, 2018
"I can't imagine a bigger pile of horse sh*t!"

Watch for the next Pruitt proclamation.
rodkeh
1 / 5 (2) Jun 14, 2018
Watch for the next Pruitt proclamation.


As if you knew anything and were able to understand any of it.
rodkeh
1 / 5 (1) Jun 14, 2018
Dick. Science not your thing, is it dear?


It obviously isn't yours, so how would you know?
gkam
1 / 5 (2) Jun 14, 2018
"As if you knew anything and were able to understand any of it."

Shall we discuss it? Or will you go hide?
antigoracle
1 / 5 (4) Jun 14, 2018
More pathological lies from the AGW Cult and their Pathological "science". While the East Antarctic gains ice, the only place the Cult can find GloBull warming is the West Antarctic where there is extensive geothermal activity. That's the magic of their evil CO2.


Dick. Science not your thing, is it dear?
-- Chicken Little Jackass
So, it's true, a Chicken Little Jackass is born every minute.
Here you go --- https://www.googl...VDt0ZJah
Find someone you trust, with a brain, to read and explain it to you.
rodkeh
1 / 5 (1) Jun 15, 2018
"As if you knew anything and were able to understand any of it."

Shall we discuss it? Or will you go hide?


Discuss what? You don't know anything and I don't speak Stupid Airhead so,......

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