15/12/2021

(USA NPR) The Exact Link Between Tornadoes And Climate Change Is Hard To Draw. Here's Why

NPR - 

Mayfield, Ky., is among the places hit by devastating tornadoes over the weekend. Brendan Smialowski/AFP via Getty Images
Dozens of tornadoes — including one massive storm that tore through more than 200 miles — struck Kentucky, Tennessee, Arkansas, Illinois, Missouri and Mississippi on Friday and Saturday, killing at least 14 people in four states and dozens more in Kentucky alone.

People following the devastating news out of the region may be wondering: (How) was the storm related to climate change?

After all, most of the extreme weather events that have dominated headlines recently — from wildfires in the U.S. to historic flooding in Western Europe — have had a clear connection to high temperatures, record rainfall and other effects of a warming planet.

The same can't exactly be said for tornadoes, however.

74 are dead and 109 unaccounted for in Kentucky as states reel from tornadoes' wrath
64 are dead and 105 unaccounted for in Kentucky as states reel from tornadoes' wrath
The 2021 Atlantic hurricane season ends as the third most active year ever
The 2021 Atlantic hurricane season ends as the third most active year ever
Scientists know that warm weather is a key ingredient in tornadoes and that climate change is altering the environment in which these kinds of storms form.

But they can't directly connect those dots, as the research into the link between climate and tornadoes still lags behind that of other extreme weather events such as hurricanes and wildfire.

That's at least in part due to a lack of data — even though the U.S. leads the world in tornadoes, averaging about 1,200 a year.

Less than 10% of severe thunderstorms produce tornadoes, which makes it tricky to draw firm conclusions about the processes leading up to them and how they might be influenced by climate change, Harold Brooks, a tornado scientist at the National Severe Storms Laboratory, told The Associated Press.

Environment Climate change is making it harder to provide clean drinking water in farm country
Climate change is making it harder to provide clean drinking water in farm country
Other factors that make that climate change attribution difficult include the quality of the observational record and the ability of models to simulate certain weather events.

The National Oceanic and Atmospheric Administration says that's the case with tornadoes.

"The observational record is not consistent and relatively short, the models remain inconclusive as to replicating tornado activity, and our understanding of how global warming and climate change will influence the different atmospheric processes that produce tornadoes (wind shear, for example) is more limited," reads a page on its website.

While scientists may not be able to conclusively connect tornado frequency or intensity to human-caused climate change, they say there are signs pointing in that direction.

Here's what they do know:

What tornadoes are and when they occur NOAA defines tornadoes as narrow, violently rotating columns of air that extend from a thunderstorm to the ground (while the wind part is invisible, tornadoes can form condensation funnels of water droplets, dust and debris).

They can be among the most violent of natural disasters, ripping homes apart, tearing through infrastructure and sending debris flying.

Tornadoes can occur in any part of the U.S. at any time of year.

National Detroit homes are being overwhelmed by flooding — and it's not just water coming in
Detroit homes are being overwhelmed by flooding — and it's not just water coming in
They have historically been associated with the Great Plains, though experts say the idea of a so-called "Tornado Alley" can be misleading since the tornado threat is a bit of a moving target.

 It shifts from the Southeast in the cooler months of the year, toward the southern and central Plains in May and June, and the northern Plains and Midwest during early summer.

When people talk about "tornado season," they are usually referring to the time of year when the U.S. sees the most tornadoes — which peaks in May and June in the southern Plains and later in the northern Plains and upper Midwest.

This weekend's tornadoes were well outside of typical tornado season, but experts say that in itself isn't rare.

What kind of conditions caused this weekend's storm Meteorologists are pointing to two contributing factors: warm temperatures and strong winds.

Thunderstorms happen when denser, drier cold air is pushed over warmer, humid air, as the AP explains, and an updraft is created when the warm air rises. Changes in the wind's speed and/or direction (known as "wind shear") can cause the updraft to spin, laying the groundwork for a tornado.

There's not usually a lot of wind instability in the winter because the air is typically not that warm or humid — but that wasn't the case over the weekend.

Climate Carbon trading gets a green light from the U.N., and Brazil hopes to earn billions
Carbon trading gets a green light from the U.N., and Brazil hopes to earn billions
States across the Midwest and South were experiencing springlike temperatures on Friday. Memphis, Tenn., saw a record high of nearly 80 degrees Fahrenheit, for example.

"The atmosphere didn't know it was December — temperatures in the 70s and 80s," tweeted Mississippi-based meteorologist Craig Ceecee.

That could be a product of many things, from the La Niña climate pattern bringing warmer-than-average conditions to the Southern U.S., to the above-average water temperatures of the Gulf of Mexico, to the warm winter weather that is increasingly common as the planet heats up.

In any case, those high temperatures lent themselves to the warm, moist air that helped form thunderstorms.

And once the storm formed, experts believe a strong wind shear (which is typical in the winter) prolonged the duration of its tornadoes.

Victor Gensini, a meteorology professor at Northern Illinois University, told AP that while tornadoes typically lose energy within minutes, this weekend's tornadoes lasted for hours.

The U.S. will likely see more tornadoes beyond their typical time and place Experts say climate change is impacting the conditions in which tornadoes form and could lead to changes in when and where the U.S. sees them.

John T. Allen, a professor of meteorology at Central Michigan University, wrote in a USA Today opinion column that while ties to climate change are still uncertain, there appears to have been an "eastward shift in tornado frequency" and increasing frequency of tornadoes in outbreaks over the past few decades.

Environment City trees are turning green early, prompting warnings about food and pollination
City trees are turning green early, prompting warnings about food and pollination
"Climate projections for the late 21st century have suggested that the conditions favorable to the development of the severe storms that produce tornadoes will increase over North America, and the impact could be greatest in the winter and fall," he added.

Brooks, of NOAA's National Severe Storms Laboratory, said the U.S. is likely to see more tornadoes in the winter (and fewer in the summer) as national temperatures rise above the long-term average.

And Gensini told Axios that projections show an increase in major outbreaks in the mid-South and Southeast.

He also compared tornado-climate change attribution to the steroids era of baseball, as Axios put it: "Pinning an individual home run on steroid use is difficult, he said, but in the aggregate the trends are evident."





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(AU The Guardian) Doubts Over Coalition’s Net Zero Target As Report Finds Soil Carbon Emissions May Increase As Climate Warms

The Guardian - 

Exclusive: Rising temperatures and shifting rainfall patterns expected to increase losses and make it more difficult to identify net carbon emissions
More carbon is stored in soil than in the atmosphere and all plant life combined, so what happens to that carbon can make a big difference. Photograph: Mick Tsikas/AAP

Fresh doubts have emerged over whether Australia can rely on boosting soil carbon to achieve its net zero emissions goals with a new New South Wales government report predicting the land sector will become a significant source of emissions in a warmer climate.

The concerns are raised in a report on soil health trends in NSW forests, published recently without fanfare by the state’s Natural Resources Commission. It examined soil organic carbon (SOC) levels in eastern NSW forests and how they may be affected by projected rising temperatures and shifting rainfall patterns.

They found major losses could be expected, particularly for southern forests, suggesting “forest managers will have to implement appropriate soil carbon-enhancing strategies even to just maintain current SOC levels”.

“This also has implications for identifying ongoing net carbon emissions from NSW lands, with respect to aiming for Net Zero Emissions and mitigating climate change,” it said.

In a separate government report detailing the modelling – known as NARCliM – used, scientists found the problem of soils releasing more carbon as conditions became warmer and drier would be statewide and would accelerate with further heating.

“From the average of the 12 models, in the upper depth interval (0 to 30cm of soil), there is a statewide average 2.5 tonnes of carbon per hectare decrease to the near-future change period [to 2040] and 5.1tC/ha to the far-future change period,” the second report said.

The models ranged from as much as 1.6tC/ha additional carbon taken up on average to losses of as much as 12tC/ha.

Scientists have long known the carbon content in soil can vary considerably based on temperatures, moisture content and soil type, among other factors. For instance, rising temperatures tend to boost microbial activity that results in more of the carbon humus in the soil digested, and extra carbon dioxide emitted.

As the Australian Academy of Technology and Engineering noted in a recent explainer, more carbon is stored in soil than in the atmosphere and all plant life combined so what happens to that carbon can make a big difference. However, measuring carbon isn’t cheap, costing about $30 a hectare a year.

Even so, governments including Australia’s commonwealth and some states are increasingly looking to soil to do much of the work to meet their emissions reduction targets.

The Morrison government’s recently released 2050 net zero plan, relies on as much as 17m tonnes of CO2 a year be sequestered in soil carbon projects for carbon neutrality to be achieved.

“Until we have better scientific evidence, we need to be cautious about relying on soil carbon to be our saviour in our net zero plans,” said Beverley Henry, an adjunct associate professor at Queensland University of Technology.

One priority should be making it cheaper to measure what carbon is contained in the soil, how it fluctuates with weather conditions, and how it can be expected to change in the future. Also, a better understanding of how human intervention can make a difference is needed since farmers can expect millions of dollars in payments for trapping more carbon.

“We need to get better, less costly soil measuring techniques,” Henry said, adding many more surveys are needed to shore-up results generated in laboratories.

“If you have more droughts, it is more difficult to consistently increase soil carbon,” she said. “The increased variability of the climate makes it harder to build soil carbon but more importantly to keep it there.”

Australia’s climate is tending to dry out, particularly in the south, CSIRO and the Bureau of Meteorology have found. Rain-bearing storm tracks are shifting southwards, with more of the moisture missing the continent.

The NSW government reports echo findings by scientists such as former CSIRO researcher Jeff Baldock. He identified a decade ago a positive feedback loop may exist if warming temperatures led to more carbon being released, in turn triggering more warming.

Baldock said rainfall is typically the “principal dictator” of how much carbon is in the soil. Modelling, such as that cited by the Natural Resources Commission, would particularly be driven by rainfall predictions. In Australia, climate science still has only broad-based projections of future shifts.

Farmers had an interest in improving the carbon content of their soils as it typically improves productivity, he said. Planting legumes, for instance, can bolster carbon levels but landholders would have to consider the trade-offs.

“Can farming businesses still be viable when the system is trying to put carbon into the ground?” Baldock said.

Guardian Australia approached Angus Taylor, the federal emissions reduction minister, and Matt Kean, the NSW treasurer and environment minister, for comment.

Chris Bowen, Labor’s federal climate spokesman, said “transparency and accountability are not things generally associated with the Morrison government”.

A Labor government would “commission a short and sharp review” of the Australian Carbon Credit Unit framework, including how they applied to farms, he said.

His NSW Labor counterpart Jihad Dib said the Natural Resources Commission report underscored the need to “listen to the science” if the land sector is to play an important role in lowering emissions.

“The only way to guarantee emissions reduction is to legislate the emissions reduction and have a clear and transparent plan to deliver it,” Dib said.

Labor’s net zero emissions bill would create a Net Zero Commission to develop and monitor emissions cuts in NSW. “This bill has passed the upper house, the NSW government should support it in the parliament in the new year,” he said.

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(AU SMH) Tenants And Apartment Owners To Benefit From New Solar Power Scheme

Sydney Morning Herald - Nick O'Malley

The third of Australian households now locked out of solar power because they are renters or lack suitable roof-space for solar cells could soon save money and cut greenhouse gas emissions under a shared solar power ownership model.

A “solar garden” being installed on the rooftop of North Coast Community Housing in 2019.

In Lismore an alliance of community groups raised money to have 35.5 kilowatts of solar cells installed on the roof of the offices of North Coast Community Housing, with the extra cash from excess power generated being returned to tenants and community groups such as Brunswick Marine Rescue.

Each of the households who were part of the scheme received a credit of about $580 on their annual power bill last year.

That relatively small so-called “solar garden” will be dwarfed by a second project soon to built on farmland at Grong Grong, in the Riverina, where people will be able to purchase “plots” in a 1 megawatt solar garden, an installation large enough to supply power to about 333 homes.

Those who buy plots in what will be known as the Haystacks solar garden can expect to pay between $4000 and $4200 for a 3KW virtual plot, a price that is likely to be slightly cheaper than installing a similar-sized unit on their own roof.

Felicity Stening, managing director of Enova Community Energy, the energy retailer linked to the two solar gardens, says a similar model has worked well in the United States but has not yet taken off in Australia, in part due to regulations that have not kept up with new ownership models.

Renewables
“It took a number of years just to have the ATO recognise that the credit on the solar power bills should be GST free,” she said.

But she added that while Australia has the world’s largest uptake of domestic solar power, about 30 per cent of the nation’s households don’t have ready access to suitable roof space for their own solar panels.

Some live in apartments, others are tenants. Kristy Walters of Community Power Agency said some people want access to solar but do not want to cut trees down that shade and cool their homes.

A survey published on Tuesday by Energy Consumers Australia shows interest is high in new models of community ownership of solar power systems.

The survey, which has been assessing public sentiment over consumer energy issues twice a year for six years, found 55 per cent of all consumers said they were interested in buying power from a local community solar garden, and 71 per cent of family households expressed interest in doing so.

Labor’s energy plan, released earlier this month, includes a commitment to co-invest $100 million to support the creation of 85 solar banks, which would operate akin to the solar gardens.

Labor says the policy could allow more than 25,000 households to share in the benefits of solar power through a co-operative ownership model.

The Energy Consumers Australia survey, conducted by Essential Research, found that as energy prices stabilised over the past year, general satisfaction with energy services improved.

It found 82 per cent of household and small business electricity consumers were satisfied with their service, up 4 per cent from December 2020, and 67 per cent of households said they were satisfied with the value for money offered by their electricity service, up 31 per cent since the survey’s low point of December 2017.

“We’ve seen consumer confidence and positivity around energy rising steadily since 2017 and that has continued in the past year,” Energy Consumers Australia chief executive Lynne Gallagher said.

She said the influx of renewable energy into our system, paired with greater monitoring and enforcement powers for the ACCC, had brought down prices and consumers had noticed the improvement.

But she added that the survey showed consumers wanted more options and more creative thinking about how they and their neighbours might generate and store energy as a net-zero future approaches.

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