أرشيف الوسم: Earth Science

Q&A: How climate change, other factors stoke Australia fires


Australia’s unprecedented wildfires are supercharged thanks to climate change, the type of trees catching fire and weather, experts say.

And these fires are so extreme that they are triggering their own thunderstorms.

Here are a few questions and answers about the science behind the Australian wildfires that so far have burned about 5 million hectares (12.35 million acres), killing at least 17 people and destroying more than 1,400 homes.

“They are basically just in a horrific convergence of events,” said Stanford University environmental studies director Chris Field, who chaired an international scientific report on climate change and extreme events. He said this is one of the worst, if not the worst, climate change extreme events he’s seen.

“There is something just intrinsically terrifying about these big wildfires. They go on for so long, the sense of hopelessness that they instill,” Field said. “The wildfires are kind of the iconic representation of climate change impacts.”


A: Scientists, both those who study fire and those who study climate, say there’s no doubt man-made global warming has been a big part, but not the only part, of the fires.

Last year in Australia was the hottest and driest on record, with the average annual temperature 2.7 degrees Fahrenheit (1.5 degrees Celsius) above the 1960 to 1990 average, according to Australia’s Bureau of Meteorology. Temperatures in Australia last month hit 121.8 F (49.9 C).

“What would have been a bad fire season was made worse by the background drying/warming trend,’’ Andrew Watkins, head of long-range forecasts at Australia’s Bureau of Meteorology, said in an email.

Mike Flannigan, a fire scientist at the University of Alberta in Canada, said Australia’s fires are “an example of climate change.”

A 2019 Australian government brief report on wildfires and climate change said, “Human-caused climate change has resulted in more dangerous weather conditions for bushfires in recent decades for many regions of Australia.”


A: The drier the fuel — trees and plants — the easier it is for fires to start and the hotter and nastier they get, Flannigan said.

“It means more fuel is available to burn, which means higher intensity fires, which makes it more difficult — or impossible — to put out,” Flannigan said.

The heat makes the fuel drier, so they combine for something called fire weather. And that determines “fuel moisture,” which is crucial for fire spread. The lower the moisture, the more likely Australian fires start and spread from lightning and human-caused ignition, a 2016 study found.

There’s been a 10% long-term drying trend in Australia’s southeast and 15% long-term drying trend in the country’s southwest, Watkins said. When added to a degree of warming and a generally southward shift of weather systems, that means a generally drier landscape.

Australia’s drought since late 2017 “has been at least the equal of our worst drought in 1902,” Australia’s Watkins said. “It has probably been driven by ocean temperature patterns in the Indian Ocean and the long term drying trend.”


A: Yes. It’s about two to four months longer, starting earlier especially in the south and east, Watkins said.

“The fires over the last three months are unprecedented in their timing and severity, started earlier in spring and covered a wider area across many parts of Australia,” said David Karoly, leader of climate change hub at Australia’s National Environmental science Program. “The normal peak fire season is later in summer and we are yet to have that.”


A: Yes. In September, Antarctica’s sudden stratospheric warming — sort of the southern equivalent of the polar vortex — changed weather conditions so that Australia’s normal weather systems are farther north than usual, Watkins said.

That means since mid-October there were persistent strong westerly winds bringing hot dry air from the interior to the coast, making the fire weather even riskier for the coasts.

“With such a dry environment, many fires were started by dry lightning events (storms that brought lightning but limited rainfall),” Watkins said.


A: It’s too early to tell the precise cause of ignition because the fires are so recent and officials are spending time fighting them, Flannigan said.

While people are a big factor in causing fires in Australia, it’s usually accidental, from cars and trucks and power lines, Flannigan said. Usually discarded cigarettes don’t trigger big fires, but when conditions are so dry, they can, he said.


A: Yes. It’s an explosive storm called pyrocumulonimbus and it can inject particles as high as 10 miles into the air.

During a fire, heat and moisture from the plants are released, even when the fuel is relatively dry. Warm air is less dense than cold air so it rises, releasing the moisture and forming a cloud that lifts and ends up a thunderstorm started by fire. It happens from time to time in Australia and other parts of the world, including Canada, Flannigan said.

“These can be deadly, dangerous, erratic and unpredictable,” he said.


A: Eucalyptus trees are especially flammable, “like gasoline on a tree,” Flannigan said. Chemicals in them make them catch fire easier, spread to the tops of trees and get more intense. Eucalyptus trees were a big factor in 2017 fires in Portugal that killed 66 people, he said.


A: You don’t. They’re just going to burn in many places until they hit the beach, Flannigan said.

“This level of intensity, direct attack is useless,” Flannigan said. “You just have to get out of the way… It really is spitting on a campfire. It’s not doing any good.”


A: “The extreme fire season in Australia in 2019 was predicted,” said Australian National University climate scientist Nerilie Abram. “The question that we need to ask is how much worse are we willing to let this get? This is what global warming of just over 1 degree C looks like. Do we really want to see the impacts of 3 degrees or more are like, because that is the trajectory we are on.”


Follow Seth Borenstein on Twitter at @borenbears .


The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.


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Going with the floe: Scientists to arrange Arctic ice camp


Scientists have chosen an ice floe on which to start establishing a analysis camp for a year-long worldwide expedition to review the Arctic, Germany’s Alfred Wegener Institute mentioned Friday.

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After a number of days of looking out, researchers discovered an appropriate floe measuring about 2.5 kilometers by 3.5 kilometers (1.5 miles by 2.2 miles) within the Arctic Sea north of Russia that can function a base for the mission, the institute mentioned.

“It might not be the proper floe, however it’s one of the best one on this a part of the Arctic, and provides higher working situations than we might have anticipated after a heat Arctic summer season,” it quoted mission chief Markus Rex as saying.

Selecting the best floe is essential to the plan of permitting the expedition vessel RV Polarstern to float with the present all through winter, when an icebreaker wouldn’t usually be capable to penetrate so deeply into the central Arctic.

“We’ll have to attend and see if it’s additionally secure sufficient to face up to the autumnal storms that are actually brewing,” Rex mentioned, including that the workforce is “ready for all situations.”

The 140 million-euro ($158 million) expedition entails a whole bunch of scientists from 19 international locations, together with Germany, america, Russia, Britain, France and China. Their intention is to gather information from the distant and inhospitable north to enhance the scientific fashions that underpin their understanding of the Arctic and local weather change.


MOSAiC expedition website: https://observe.mosaic-expedition.org/


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Experts say adapting to climate change can pay off manifold


A group of leaders from business, politics and science have called for a massive investment in adapting to climate change over the next decade, arguing it would reap significant returns as countries avoid catastrophic losses and boost their economies.

The Global Commission on Adaptation, comprising dozens of prominent figures including Microsoft co-founder Bill Gates and former U.N. Secretary-General Ban Ki-moon, urged governments and businesses to tackle the inevitable consequences of climate change, in addition to trying to curb it.

In their 81-page report released Tuesday, the experts proposed investing $1.8 trillion between 2020 and 2030 in areas such as early warning systems, infrastructure that can withstand rising sea levels and extreme weather, and boosting agriculture to cope with droughts. Other areas they propose investing in are bolstering scarce water resources and improving mangrove forests that provide key protection to vulnerable shorelines in developing nations.

Ban cited Bangladesh’s response to two devastating cyclones as a good example of the way countries can adapt to environmental threats. Following the deaths of hundreds of thousands of people in 1970 and 1991, the South Asian nation reinforced flood defenses, built shelters and trained volunteers, sharply cutting the death toll in subsequent storms.

He also pointed to recent environmental devastation in the Bahamas as further proof of the importance of preparing for climate change.

“Just one cyclone devastated the country,” Ban said. “Of course there’s a very good way of weather forecasting but when these countries are well-prepared in infrastructures and provide some shelters (…) then we could have reduced as much as possible the damages that we have seen now.”

The commission said protection measures have allowed valuable land to be used in places such as the Netherlands and London that would otherwise have risked flooding.

While rich countries already have the means to invest in such measures, poor nations risk losing out, the group said.

“If we do not act now, climate change will supercharge the global gap between the haves and have-nots,” said Ban.

Christiana Figueres, a former U.N. official who helped forge the 2015 Paris accord, said talk on adaptation has for years been neglected, compared with efforts to mitigate, or lessen, climate change.

“Mitigation and adaptation are actually two sides of the very same coin,” she said. “If we delay mitigation any further we will never be able to adapt sufficiently to keep humanity safe. And if we delay adaptation we will pay such a high price that we would never be able to look at ourselves in the mirror.”

The report was released ahead of a U.N. summit on climate change later this month.


Sam McNeil in Beijing contributed to this report.


Global Commission on Adaptation: https://gca.org/global-commission-on-adaptation/home


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New UN warming report sees hungry future that may be prevented


Human-caused local weather change is dramatically degrading the Earth’s land and the best way folks use the land is making world warming worse, a brand new United Nations scientific report says. That creates a vicious cycle which is already making meals dearer, scarcer and fewer nutritious.

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“The cycle is accelerating,” stated NASA local weather scientist Cynthia Rosenzweig, a co-author of the report. “The specter of local weather change affecting folks’s meals on their dinner desk is rising.”

But when folks change the best way they eat, develop meals and handle forests, it may assist save the planet from a far hotter future, scientists stated.

Earth’s land lots, that are solely 30% of the globe, are warming twice as quick because the planet as an entire. Whereas heat-trapping gases are inflicting issues within the ambiance, the land has been much less talked about as a part of local weather change. A particular report, written by greater than 100 scientists and unanimously accepted by diplomats from nations world wide Thursday at a gathering in Geneva, proposed potential fixes and made extra dire warnings.

“The best way we use land is each a part of the issue and in addition a part of the answer,” stated Valerie Masson-Delmotte, a French local weather scientist who co-chairs one of many panel’s working teams. “Sustainable land administration will help safe a future that’s comfy.”

Scientists at Thursday’s press convention emphasised each the seriousness of the issue and the necessity to make societal adjustments quickly.

“We do not need a message of despair,” stated science panel official Jim Skea, a professor at Imperial School London. “We need to get throughout the message that each motion makes a distinction.”

Nonetheless the stark message hit house laborious for a few of the authors.

“I’ve misplaced plenty of sleep about what the science is saying. As an individual, it is fairly scary,” Koko Warner, a supervisor within the U.N. Local weather Change secretariat who helped write a report chapter on danger administration and decision-making, advised The Related Press after the report was introduced on the World Meteorological Group headquarters in Geneva. “We have to act urgently.”

The report stated local weather change already has worsened land degradation, brought on deserts to develop, permafrost to thaw and made forests extra weak to drought, fireplace, pests and illness. That is occurred at the same time as a lot of the globe has gotten greener due to further carbon dioxide within the air. Local weather change has additionally added to the forces which have diminished the variety of species on Earth.

“Local weather change is basically slamming the land,” stated World Sources Institute researcher Kelly Levin, who wasn’t a part of the examine.

And the long run may very well be worse.

“The soundness of meals provide is projected to lower because the magnitude and frequency of maximum climate occasions that disrupt meals chains will increase,” the report stated.

Within the worst-case state of affairs, meals safety issues change from reasonable to excessive danger with only a few extra tenths of a level of warming from now. They go from excessive to “very excessive” danger with simply one other 1.Eight levels Fahrenheit (1 diploma Celsius) of warming from now.

“The potential danger of multi-breadbasket failure is rising,” NASA’s Rosenzweig stated. “Simply to offer examples, the crop yields have been effected in Europe simply within the final two weeks.”

Scientists had lengthy thought one of many few advantages of upper ranges of carbon dioxide, the main heat-trapping gasoline, was that it made crops develop extra and the world greener, Rosenzweig stated. However quite a few research present that the excessive ranges of carbon dioxide scale back protein and vitamins in lots of crops.

For instance, excessive ranges of carbon within the air in experiments present wheat has 6% to 13% much less protein, 4% to 7% much less zinc and 5% to eight% much less iron, she stated.

However higher farming practices — akin to no-till agricultural and higher focused fertilizer purposes — have the potential to combat world warming too, lowering carbon air pollution as much as 18% of present emissions ranges by 2050, the report stated.

If folks change their diets, lowering pink meat and rising plant-based meals, akin to fruits, greens and seeds, the world can save as a lot as one other 15% of present emissions by mid-century. It will additionally make folks extra wholesome, Rosenzweig stated.

The science panel stated they don’t seem to be telling folks what to eat as a result of that is a private selection.

Nonetheless, Hans-Otto Pörtner, a panel chief from Germany who stated he misplaced weight and felt higher after lowering his meat consumption, advised a reporter that if she ate much less ribs and extra greens “that is a superb determination and you’ll assist the planet scale back greenhouse gasoline emissions.”

Lowering meals waste can combat local weather change much more. The report stated that between 2010 and 2016, world meals waste accounted for 8% to 10% of heat-trapping emissions.

“At present 25%-30% of complete meals produced is misplaced or wasted,” the report stated. Fixing that may release hundreds of thousands of sq. miles of land.

With simply one other 0.9 levels F of warming (0.5 levels C), which may occur within the subsequent 10 to 30 years, the chance of unstable meals provides, wildfire harm, thawing permafrost and water shortages in dry areas “are projected to be excessive,” the report stated.

At one other 1.Eight levels F of warming (1 diploma C) from now, which may occur in about 50 years, it stated these dangers “are projected to be very excessive.”

Most situations predict the world’s tropical areas can have “unprecedented weather conditions by the mid-to-late 21st century,” the report famous.

Agriculture and forestry collectively account for about 23% of the heat-trapping gases which are warming the Earth, barely lower than from automobiles, vans, boats and planes. Add in transporting meals, power prices, packaging and that grows to 37%, the report stated.

However the land can also be an excellent carbon “sink,” which sucks heat-trapping gases out of the air.

From about 2007 to 2016, agriculture and forestry yearly put 5.7 billion tons (5.2 billion metric tons) of carbon dioxide into the air, however pulled 12.three billion tons (11.2 billion metric tons) of it out.

“This extra reward from nature is proscribed. It is not going to proceed endlessly,” stated examine co-author Luis Verchot, a scientist on the Worldwide Middle for Tropical Agriculture in Colombia. “If we proceed to degrade ecosystems, if we proceed to transform pure ecosystems, we proceed to deforest and we proceed to destroy our soils, we will lose this pure subsidy.”

General land emissions are rising, particularly due to reducing down forests within the Amazon in locations akin to Brazil, Colombia and Peru, Verchot stated.

Latest forest administration adjustments in Brazil “contradicts all of the messages which are popping out of the report,” Pörtner stated.

Saying “our present way of life and our financial system dangers our future and the way forward for our kids,” Germany’s surroundings minister, Svenja Schulze, questioned whether or not it is sensible for a rustic like Germany to import massive quantities of soy from Latin America, the place forests are being destroyed to plant the crop, to feed unsustainable numbers of livestock in Germany.

“We ought to acknowledge that we’ve profound limits on the quantity of land out there and we’ve to watch out about how we put it to use,” stated Stanford College environmental sciences chief Chris Subject, who wasn’t a part of the report.


AP Science Author Seth Borenstein reported from Washington. Frank Jordans contributed from Berlin.


For extra Related Press tales about local weather change, go to https://www.apnews.com/Local weather


Observe Seth Borenstein on Twitter: @borenbears


The Related Press Well being and Science Division receives assist from the Howard Hughes Medical Institute’s Division of Science Schooling. The AP is solely chargeable for all content material.


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