Why 2℃ Of Global Warming Is Much Worse For Australia Than 1.5℃

Why 2℃ Of Global Warming Is Much Worse For Australia Than 1.5℃

Australia is a land of extremes. We’ve experienced all manner of climate extremes over the past few years, from heatwaves (both on land and over the Great Barrier Reef), to droughts and flooding rains.

We can already link some of these recent extreme events to climate change. But for others, the link is less clear.

So far we have had about 1℃ of global warming above the average pre-industrial climate. So how will extreme weather events change with more warming in the future? Will they become more frequent? Will they become more severe?

We have investigated these questions in our new research, published today in Nature Climate Change.

Climate targets

The Paris Agreement, brokered in 2015, committed the world’s governments to:

Holding the increase in the global average temperature to well below 2℃ above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5℃ above pre-industrial levels, recognising that this would significantly reduce the risks and impacts of climate change.

It is vital that we understand how climate extremes in Australia might change if we limit global warming to either 1.5℃ or 2℃, and what the implications might be of pursuing the more lenient target rather than the more ambitious one.

In our study we used state-of-the-art climate model simulations to examine the changing likelihood of different climate extremes under four different scenarios: a natural world without any human-caused climate change; the world of today; a 1.5℃ warmer world; and a 2℃ warmer one.

Heat extremes are here to stay

First, we looked at hot Australian summers, like the record-breaking “angry summer” of 2012-13.

We already knew that human influences on the climate had increased the likelihood of hot summers. Our results show that this trend would continue with future warming. In fact, in a world of 2℃ global warming, even an average summer would outstrip those historically hot ones like 2012-13.

Australian summer temperatures are strongly related to the El Niño-Southern Oscillation, with hot summers more likely to occur during El Niño events, and cooler ones during La Niña episodes.

In the past, a summer as hot as 2012-13 would have been very unlikely during a La Niña. But our modelling predicts that with either 1.5℃ or 2℃ of global warming, we could expect similarly angry summers to occur during both El Niño and La Niña periods.

We already know that the sea surface temperatures associated with mass bleaching of much of the Great Barrier Reef in early 2016 would have been virtually impossible without climate change. If the world continues to warm to either the 1.5℃ or 2℃ levels, very warm seas like we saw early last year would become the norm.

Why 2℃ Of Global Warming Is Much Worse For Australia Than 1.5℃ High sea temperatures linked to coral bleaching in Great Barrier Reef will become more likely in a warmer world. Author provided

In fact, our research suggests that with 2℃ of global warming, the future average sea temperatures around the Great Barrier Reef would be even hotter than the extremes observed around the time of the 2016 bleaching.

Less change for heavy rains and droughts

In December 2010 Queensland was devastated by severe flooding following very heavy rainfall. Our analysis suggests that this kind of event is highly unusual, and may well continue to be so. There isn’t a clear signal for an increase or decrease in those events with ongoing climate warming.

Natural climate variability seems to play a greater role than human-driven climate change (at least below the 2℃ threshold) when it comes to influencing Australian heavy rainfall events.

The Millennium Drought across southeast Australia led to water shortages and crop failures. Drought is primarily driven by a lack of rainfall, but warmer temperatures can exacerbate drought impacts by increasing evaporation.

Our results showed that climate change is increasing the likelihood of hot and dry years like we saw in 2006 across southeast Australia. At 1.5℃ and 2℃ of global warming these events would probably be more frequent than they are in today’s world.

Why 2℃ Of Global Warming Is Much Worse For Australia Than 1.5℃ Heat extremes are much more common at 2℃ than 1.5℃ Author provided

Not a lost cause

It is clear that Australia is going to suffer from more frequent and more intense climate extremes as the world warms towards (and very likely beyond) the levels described in the Paris Agreement.

If we miss these targets, the warming will continue and the extremes we experience in Australia are going to be even worse.

With either 1.5℃ or 2℃ global warming, we will see more extremely hot summers across Australia, more frequent marine heatwaves of the kind that can cause bleaching of the Great Barrier Reef, and probably more frequent drought conditions too.

The more warming we experience, the worse the impacts will be. The solution is clear. To limit global warming, the world’s nations need to reduce their greenhouse gas emissions – fast.The Conversation

About The Author

Andrew King, Climate Extremes Research Fellow, University of Melbourne; Ben Henley, Research Fellow in Climate and Water Resources, University of Melbourne, University of Melbourne, and David Karoly, Professor of Atmospheric Science, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Related Books

Life After Carbon: The Next Global Transformation of Cities

by Peter Plastrik , John Cleveland
1610918495The future of our cities is not what it used to be. The modern-city model that took hold globally in the twentieth century has outlived its usefulness. It cannot solve the problems it helped to create—especially global warming. Fortunately, a new model for urban development is emerging in cities to aggressively tackle the realities of climate change. It transforms the way cities design and use physical space, generate economic wealth, consume and dispose of resources, exploit and sustain the natural ecosystems, and prepare for the future. Available On Amazon

The Sixth Extinction: An Unnatural History

by Elizabeth Kolbert
1250062187Over the last half-billion years, there have been Five mass extinctions, when the diversity of life on earth suddenly and dramatically contracted. Scientists around the world are currently monitoring the sixth extinction, predicted to be the most devastating extinction event since the asteroid impact that wiped out the dinosaurs. This time around, the cataclysm is us. In prose that is at once frank, entertaining, and deeply informed, New Yorker writer Elizabeth Kolbert tells us why and how human beings have altered life on the planet in a way no species has before. Interweaving research in half a dozen disciplines, descriptions of the fascinating species that have already been lost, and the history of extinction as a concept, Kolbert provides a moving and comprehensive account of the disappearances occurring before our very eyes. She shows that the sixth extinction is likely to be mankind's most lasting legacy, compelling us to rethink the fundamental question of what it means to be human. Available On Amazon

Climate Wars: The Fight for Survival as the World Overheats

by Gwynne Dyer
1851687181Waves of climate refugees. Dozens of failed states. All-out war. From one of the world’s great geopolitical analysts comes a terrifying glimpse of the strategic realities of the near future, when climate change drives the world’s powers towards the cut-throat politics of survival. Prescient and unflinching, Climate Wars will be one of the most important books of the coming years. Read it and find out what we’re heading for. Available On Amazon

From The Publisher:
Purchases on Amazon go to defray the cost of bringing you InnerSelf.comelf.com, MightyNatural.com, and ClimateImpactNews.com at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.

 

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook-icontwitter-iconrss-icon

 Get The Latest By Email

{emailcloak=off}

LATEST VIDEOS

300 Million Face Severe Risk of Climate-Fueled Coastal Flooding by 2050
by Democracy Now!
As a shocking new report finds that many coastal cities will be flooded by rising sea levels by 2050, Chile’s President…
Climate Warning: California Continues To Burn, Data Estimates Of Global Flooding
by MSNBC
Ben Strauss, CEO and Chief Scientist of Climate Central joins MTP Daily to discuss alarming new information about…
Stanford Climate Solutions
by Stanford
Climate change has brought us to a defining moment in human history.
Buying Renewable Energy From Your Neighbor
by NBC News
Brooklyn Microgrid, a project of parent company LO3 Energy, is looking to disrupt the more than 100-year-old energy…
Debate Over Pipelines Clouds Concern For Climate Change
by Global News
Climate experts are warning that Canada shouldn't ignore the wildfire crisis in California
How Climate Change Affects Wildfires
by NBC News
NYU environmental studies professor David Kanter explains how climate change is creating the perfect conditions for…
Rice Bowl Of Malaysia Threatened By Climate Change
by The Star Online
Kedah is known as the country’s “Rice Bowl,” and it is especially suitable for the growing of the grain.
Maine Cow's Seaweed Diet Research Could Help Climate Change
by News Center Maine
Research in Maine will measure the methane released by cows who have been fed a seaweed diet.

LATEST ARTICLES

Why The Global Climate Treaty Is Not Working
Why The Global Climate Treaty Is Not Working
by Tim Radford
Three out of four nations have yet to start to honour the global climate treaty. The world waits, the seas go on rising…
Why Taxes Are Better Than Bans For Keeping Homeowners From Rebuilding In Fire-plagued Areas
Why Taxes Are Better Than Bans For Keeping Homeowners From Rebuilding In Fire-plagued Areas
by Alexander Smith
Almost 200,000 Californians have been ordered to evacuate as ferocious winds drove several wildfires near Los Angeles,…
How Will 20 Years Of Houston’s Growth Affect Flooding?
How Will 20 Years Of Houston’s Growth Affect Flooding?
by InnerSelf Staff
A new way to show exactly how much the city of Houston has changed in the last two decades gives a dramatic visual…
Why Australia Could Fall Apart Under Climate Change
Why Australia Could Fall Apart Under Climate Change
by Ross Garnaut
Four years ago in December 2015, every member of the United Nations met in Paris and agreed to hold global temperature…
How Greenhouse Gases Drive Australia's Bushfires
How Greenhouse Gases Drive Australia's Bushfires
by Andrew Burgess
Australia’s bushfires are feeding on heat from the climate change happening in the tropics, but its government doesn’t…
How Children Born Now Face Multiple Climate Health Risks
How Children Born Now Face Multiple Climate Health Risks
by Tim Radford
Multiple climate health risks threaten today’s babies. They may grow up hungrier, more diseased and facing more…
This Is What Australia's Growing Cities Need To Do To Avoid Running Dry
This Is What Australia's Growing Cities Need To Do To Avoid Running Dry
by Ian Wright
The increasing thirst of Australia’s biggest cities routinely exceeds our capacity to rely on rainfall for drinking…
Evangelicals In Brazil See Abuse Of God's Earth As A Sin – But Will They Fight To Save The Amazon?
Evangelicals In Brazil See Abuse Of God's Earth As A Sin – But Will They Fight To Save The Amazon?
by Amy Erica Smith
When the Brazilian city of São Paulo abruptly went dark at midday on Aug. 19, there was talk of the Apocalypse – not…