Tag Archives: Environme

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

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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.”

Q: IS CLIMATE CHANGE REALLY A FACTOR?

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.”

Q: HOW DOES CLIMATE CHANGE MAKE THESE FIRES WORSE?

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.”

Q: HAS AUSTRALIA’S FIRE SEASON CHANGED?

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.”

Q: IS WEATHER, NOT JUST LONG-TERM CLIMATE, A FACTOR?

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.

Q: ARE PEOPLE STARTING THESE FIRES? IS IT ARSON?

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.

Q: ARE THESE FIRES TRIGGERING THUNDERSTORMS?

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.

Q: ARE THE AUSTRALIAN TREES PRONE TO BURNING?

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.

Q: HOW CAN YOU FIGHT THESE HUGE AUSTRALIA FIRES?

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.”

Q: WHAT’S THE LONG-TERM FIRE FUTURE LOOK LIKE FOR AUSTRALIA?

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.”

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Follow Seth Borenstein on Twitter at @borenbears .

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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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Company may maintain Three Mile Island nuclear particles in Idaho

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The partially melted reactor core from the worst nuclear accident in U.S. historical past may stay in Idaho for an additional 20 years if regulators finalize a license extension sought by the U.S. Vitality Division, officers mentioned Monday.

The core from Three Mile Island in Pennsylvania partially melted in 1979, an occasion that modified the way in which Individuals view nuclear expertise.

The U.S. Nuclear Regulatory Fee has decided there can be no important affect from extending the license to retailer the core on the 890-square-mile (2,305-square-kilometer) web site that features Idaho Nationwide Laboratory.

“No important radiological or non-radiological impacts are anticipated from continued regular operations,” the fee mentioned about its discovering.

The company would even have to finish a security analysis report earlier than renewing the license. Fee spokesman David McIntyre mentioned that can probably occur within the subsequent a number of days.

Holly Harris, govt director of the Idaho-based nuclear watchdog group Snake River Alliance, wasn’t instantly out there to remark.

The Vitality Division web site sits atop the Jap Snake Plain Aquifer, a Lake Erie-size underground physique of water that provides cities and farms within the area with water.

The brand new license can be good by means of 2039, 4 years previous a deadline the Vitality Division initially set with Idaho to take away the radioactive waste.

State and federal officers say the waste may nonetheless be shipped out of Idaho forward of the 2035 deadline and wouldn’t have an effect on the 1995 settlement that accommodates penalties for missed deadlines.

Idaho is already fining the Vitality Division for lacking a deadline involving radioactive liquid waste saved on the web site.

It isn’t clear the place the Three Mile Island waste could possibly be moved, because the U.S. would not have a delegated repository.

The U.S. Vitality Data Administration says there’s some 77,000 tons (70,000 metric tons) of spent nuclear gasoline saved at business nuclear websites across the nation as a result of there is no place else to place it.

The Division of Vitality mentioned no further materials can be added to the waste storage web site in Idaho.

The earlier license expired in March. It mentioned the utmost quantity of Three Mile Island particles that could possibly be saved on the Idaho web site was 183,000 kilos (83,000 kilograms) of broken nuclear gasoline assemblies and 308,000 kilos (140,000 kilograms) of fabric faraway from the reactor vessel.

Court docket battles between Idaho and the federal authorities culminated with the 1995 settlement requiring the Vitality Division to wash up the Idaho web site in addition to stop the world from changing into the nation’s nuclear waste dump.

Exelon Technology, the corporate that owns the remaining nuclear energy plant at Three Mile Island, has mentioned it should shut down the power by the top of this month.

The corporate blamed financial challenges and what it mentioned are market flaws that fail to acknowledge the worth of nuclear crops.

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