Droughts And Flooding Rains Already More Likely As Climate Change Plays Havoc With Pacific Weather

Droughts And Flooding Rains Already More Likely As Climate Change Plays Havoc With Pacific Weather

 

Global warming has already increased the risk of major disruptions to Pacific rainfall, according to our research published today in Nature Communications. The risk will continue to rise over coming decades, even if global warming during the 21st century is restricted to 2℃ as agreed by the international community under the Paris Agreement.

In recent times, major disruptions have occurred in 1997-98, when severe drought struck Papua New Guinea, Samoa and the Solomon Islands, and in 2010-11, when rainfall caused widespread flooding in eastern Australia and severe flooding in Samoa, and drought triggered a national emergency in Tuvalu.

These rainfall disruptions are primarily driven by the El Niño/La Niña cycle, a naturally occurring phenomenon centred on the tropical Pacific. This climate variability can profoundly change rainfall patterns and intensity over the Pacific Ocean from year to year.

Rainfall belts can move hundreds and sometimes thousands of kilometres from their normal positions. This has major impacts on safety, health, livelihoods and ecosystems as a result of severe weather, drought and floods.

Recent research concluded that unabated growth in greenhouse gas emissions over the 21st century will increase the frequency of such disruptions to Pacific rainfall.

But our new research shows even the greenhouse cuts we have agreed to may not be enough to stop the risk of rainfall disruption from growing as the century unfolds.

Changing climate

In our study we used a large number of climate models from around the world to compare Pacific rainfall disruptions before the Industrial Revolution, during recent history, and in the future to 2100. We considered different scenarios for the 21st century.

One scenario is based on stringent mitigation in which strong and sustained cuts are made to global greenhouse gas emissions. This includes in some cases the extraction of carbon dioxide from the atmosphere.

In another scenario emissions continue to grow, and remain very high throughout the 21st century. This high-emissions scenario results in global warming of 3.2-5.4℃ by the end of the century (compared with the latter half of the 19th century).

The low-emissions scenario - despite the cuts in emissions - nevertheless results in 0.9-2.3℃ of warming by the end of the century.

Increasing risk

Under the high-emissions scenario, the models project a 90% increase in the number of major Pacific rainfall disruptions by the early 21st century, and a 130% increase during the late 21st century, both relative to pre-industrial times. The latter means that major disruptions will tend to occur every four years on average, instead of every nine.

The increase in the frequency of rainfall disruption in the models arises from an increase in the frequency of El Niño and La Niña events in some models, and an increase in rainfall variability during these events as a result of global warming. This boost occurs even if the character of the sea-surface temperature variability arising from El Niño and La Niña events is unchanged from pre-industrial times.

Although heavy emissions cuts lead to a smaller increase in rainfall disruption, unfortunately even this scenario does not prevent some increase. Under this scenario, the risk of rainfall disruption is projected to be 56% higher during the next three decades, and to remain at least that high for the rest of the 21st century.

The risk has already increased

While changes to the frequency of major changes in Pacific rainfall appear likely in the future, is it possible that humans have already increased the risk of major disruption?

It seems that we have: the frequency of major rainfall disruptions in the climate models had already increased by around 30% relative to pre-industrial times prior to the year 2000.

As the risk of major disruption to Pacific rainfall had already increased by the end of the 20th century, some of the disruption actually witnessed in the real world may have been partially due to the human release of greenhouse gases. The 1982-83 super El Niño event, for example, might have been less severe if global greenhouse emissions had not risen since the Industrial Revolution.

Most small developing island states in the Pacific have a limited capacity to cope with major floods and droughts. Unfortunately, these vulnerable nations could be exposed more often to these events in future, even if global warming is restricted to 2℃.

These impacts will add to the other impacts of climate change, such as rising sea levels, ocean acidification and increasing temperature extremes.The Conversation

About The Author

Scott B. Power, Head of Climate Research/International Development Manager, Australian Bureau of Meteorology; Brad Murphy, Manager, Climate Data Services, Australian Bureau of Meteorology; Christine Chung, Research Scientist, Australian Bureau of Meteorology; François Delage, Assistant scientist, Australian Bureau of Meteorology, and Hua Ye, Climate IT Officer, Australian Bureau of Meteorology

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

PBS Nova's Polar Extremes
PBS Nova's Polar Extremes
by PBS
In this two-hour special, renowned paleontologist Kirk Johnson takes us on an epic adventure through time at the polar…
A huge iceberg just broke off West Antarctica’s most endangered glacier
A Huge Iceberg Just Broke Off West Antarctica’s Most Endangered Glacier
by Madeleine Stone
Huge blocks of ice regularly shear away from Antarctica’s ice shelves, but the losses are speeding up.
The Rise Of Solar Power
by CNBC
Solar power is on the rise. You can see the evidence on rooftops and in the desert, where utility-scale solar plants…
World's Largest Batteries: Pumped Storage
by Practical Engineering
The vast majority of our grid-scale storage of electricity uses this clever method.
Hydrogen Fuels Rockets, But What About Power For Daily Life?
Hydrogen Fuels Rockets, But What About Power For Daily Life?
by Zhenguo Huang
Have you ever watched a space shuttle launch? The fuel used to thrust these enormous structures away from Earth’s…
Fossil Fuel Production Plans Could Push Earth off a Climate Cliff
by The Real News Network
The United Nations is beginning its climate summit in Madrid.
Big Rail Spends More on Denying Climate Change than Big Oil
by The Real News Network
A new study concludes that rail is the industry that's injected the most money into climate change denial propaganda…
Did Scientists Get Climate Change Wrong?
by Sabine Hossenfelder
Interview with Prof Tim Palmer from the University of Oxford.

LATEST ARTICLES

Natural Flood Management Would Be Overwhelmed By Britain's Winter Super-floods
Natural Flood Management Would Be Overwhelmed By Britain's Winter Super-floods
by Robert Wilby and Simon Dadson
As large swathes of the UK endure the worst floods in living memory, hearts and minds are rightly focused on protecting…
Keeping The City Cool Isn't Just About Tree Cover – It Calls For A Commons-based Climate Response
Keeping The City Cool Isn't Just About Tree Cover – It Calls For A Commons-based Climate Response
by Abby Mellick Lopes and Cameron Tonkinwise
A recent report by the Greater Sydney Commission singles out urban heat as one of four priority areas given our coming…
Low Flammability Plants Could Help Our Homes Survive Bushfires
Low Flammability Plants Could Help Our Homes Survive Wildfires
by Tim Curran, et al
Destructive wildfires are becoming more common in many parts of the world and are predicted to worsen with climate…
Carbon Pricing May Be Overrated, If History Is Any Indication
Carbon Pricing May Be Overrated, If History Is Any Indication
by Cameron Roberts
A common demand in discussions about climate change is to respect the science. This is appropriate. We should all be…
Here Are 5 Practical Ways Trees Can Help Us Survive Climate Change
Here Are 5 Practical Ways Trees Can Help Us Survive Climate Change
by Gregory Moore
As the brutal reality of climate change dawned this summer, you may have asked yourself a hard question: am I…
A Military Perspective On Climate Change Could Bridge The Gap Between Believers And Doubters
A Military Perspective On Climate Change Could Bridge The Gap Between Believers And Doubters
by Michael Klare
As experts warn that the world is running out of time to head off severe climate change, discussions of what the U.S.…
Nearly 80% Of Australians Affected In Some Way By The Bushfires, New Survey Shows
Nearly 80% Of Australians Affected In Some Way By The Bushfires, New Survey Shows
by Nicholas Biddle, et al
Our research shows the vast majority of Australians were touched in some way by the fires. We asked about eight…
Changing Climate Has Stalled Australian Wheat Yields
Changing Climate Has Stalled Australian Wheat Yields
by Zvi Hochman; David L. Gobbett, and Heidi Horan, CSIRO
Australia’s wheat yields more than trebled during the first 90 years of the 20th century but have stalled since 1990.…