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Climate Change

Tibetan glaciers face multiple threats from South Asia air pollution



(Last Updated On: December 10, 2022)

The Tibetan Plateau is the largest and highest such elevation in the world, and is a critical water resource for almost two billion people in Asia, but the land mass, known as the “Asian water tower”, is under a growing climate threat.

Scientists say the primary culprit – an air pollutant known as black carbon – could result in unprecedented melting of the plateau’s glaciers, Asia One reported this week.

A study led by researchers from the Chinese Academy of Sciences’ Northwest Institute of Eco-Environment and Resources has found that increasing concentrations of black carbon in South Asia have reduced levels of summer precipitation over the Southern Tibetan Plateau, which in turn has accelerated the shrinking of that region’s glaciers.

The findings have prompted the scientists to call for cuts in black carbon emissions in South Asia to preserve a crucial water balance on the plateau and avoid future water shortages and geological hazards.

Black carbon – a type of soot – is a component of fine particulate matter. It results from the incomplete combustion of fossil fuels and biomass.

Black carbon emissions contribute to global warming by absorbing solar energy and then heating the surroundings. When deposited on ice or snow, black carbon reduces surface albedo, or the ability to reflect sunlight, which then heats the surface and quickens glacial melting. Ice covered regions like the Arctic, Antarctic and the Himalayas are all vulnerable to black carbon emissions, Asia One reported.

But in the case of the Tibet Plateau, the world’s third largest store of ice, such emissions do not have to travel far. South Asian countries are some of the world’s worst air polluters. Black carbon emissions from the Indian subcontinent are carried aloft to the Tibetan Plateau and worsen glacial melting, in what the researchers call a “direct effect”.

In their stud the researchers also discovered that black carbon originating from South Asia has impacted the glaciers by reducing the amount of precipitation in the Southern Tibetan Plateau.

In their analysis of precipitation data from 1961 to 2016, the researchers found that summer precipitation amounts over the Southern Tibetan Plateau began to decline in 2004 by an average of 4.4mm a year.

Summer precipitation accounts for more than 60 percent of the total annual precipitation over the plateau, so declines in the seasonal rains resulted in glacial shrinkage, the study said. And since the beginning of this century, the problem has accelerated.

Kang Shichang, one of the study’s corresponding authors and a researcher with the Chinese Academy of Sciences, said: “Black carbon emissions are expected to increase in South Asia. It is imperative to reduce emissions in South Asia to protect the Asian water tower.”

Climate Change

Rising Antarctic ice melt will dramatically slow global ocean flows, study finds



(Last Updated On: March 30, 2023)

Rapidly melting Antarctic ice is dramatically slowing down the flow of water through the world’s oceans, and could have a disastrous impact on global climate, the marine food chain and even the stability of ice shelves, new research has found, Reuters reported.

The “overturning circulation” of the oceans, driven by the movement of denser water towards the sea floor, helps deliver heat, carbon, oxygen and vital nutrients around the globe.

But deep ocean water flows from the Antarctic could decline by 40% by 2050, according to a study published on Wednesday in the journal Nature.

“That’s stunning to see that happen so quickly,” said Alan Mix, a paleoclimatologist at Oregon State University and co-author on the latest Intergovernmental Panel on Climate Change assessments, who was not involved in the study. “It appears to be kicking into gear right now. That’s headline news.”

As temperatures rise, freshwater from Antarctica’s melting ice enters the ocean, reducing the salinity and density of the surface water and diminishing that downward flow to the sea’s bottom, read the report.

While past research has looked at what could happen to similar overturning circulation in the North Atlantic – the mechanism behind the doomsday scenario that would see Europe suffer from an Arctic blast as heat transport falters – less has been done on Antarctic bottom water circulation.

Scientists relied on around 35 million computing hours over two years to crank through a variety of models and simulations up to the middle of this century, finding deepwater circulation in the Antarctic could weaken at twice the rate of decline in the North Atlantic.

“They are massive volumes of water… and they are bits of the ocean that have been stable for a long time,” said study co-author Matthew England, an oceanographer at the University of New South Wales, in a news briefing.

The effect of meltwater on global ocean circulation has not yet been included in the complex models used by the IPCC to describe future climate change scenarios, but it is going to be considerable, England said.

Ocean overturning allows nutrients to rise up from the bottom, with the Southern Ocean supporting about three-quarters of global phytoplankton production, the base of the food chain, said a second study co-author, Steve Rintoul.

“If we slow the sinking near Antarctica, we slow down the whole circulation and so we also reduce the amount of nutrients that get returned from the deep ocean back up to the surface,” said Rintoul, a fellow at Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO).

The study’s findings also suggest the ocean would not be able to absorb as much carbon dioxide as its upper layers become more stratified, leaving more CO2 in the atmosphere, Reuters reported.

The study showed that warm water intrusions in the western Antarctican ice shelf would increase, but it did not look at how this might create a feedback effect and generate even more melting.

“It doesn’t include the disaster scenarios,” said Mix. “In that sense, it’s actually kind of conservative.”

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Climate Change

At least 26 dead in tornadoes in Mississippi and Alabama



(Last Updated On: March 26, 2023)

Rescuers raced Saturday to search for survivors and help hundreds of people left homeless after a powerful tornado cut a devastating path through Mississippi in the United States, killing at least 25 people, injuring dozens, and flattening entire blocks as it carved a path of destruction for more than an hour.

One person was also killed in Alabama.

The tornado devastated a swath of the Mississippi Delta town of Rolling Fork, reducing homes to piles of rubble, flipping cars on their sides and toppling the town’s water tower. Residents hunkered down in bath tubs and hallways during Friday night’s storm and later broke into a John Deere store that they converted into a triage center for the wounded.

“There’s nothing left,” said Wonder Bolden, holding her granddaughter, Journey, while standing outside the remnants of her mother’s now-leveled mobile home in Rolling Fork.

Based on early data, the tornado received a preliminary EF-4 rating, the National Weather Service office in Jackson said late Saturday in a tweet. An EF-4 tornado has top wind gusts between 265 kph and 320 kph, according to the service. The Jackson office cautioned it was still gathering information on the tornado.

The Mississippi Emergency Management Agency announced late Saturday afternoon in a tweet that the death toll had risen to 25 and that dozens of people were injured. Four people previously reported missing had been found.

Other parts of the Deep South were digging out from damage caused by other suspected twisters. One man died in Morgan County, Alabama, the sheriff’s department there said in a tweet.

Throughout Saturday, survivors walked around dazed and in shock as they broke through debris and fallen trees with chain saws, searching for survivors. Power lines were pinned under decades-old oaks, their roots torn from the ground.

Mississippi Governor Tate Reeves issued a State of Emergency and vowed to help rebuild as he headed to view the damage in an area speckled with wide expanses of cotton, corn and soybean fields and catfish farming ponds. President Joe Biden also promised federal help, describing the damage as “heartbreaking.”

The supercell that produced the deadly twister also appeared to produce tornadoes that caused damage in northwest and north-central Alabama, said Brian Squitieri, a severe storms forecaster with the weather service’s Storm Prediction Center in Norman, Oklahoma.

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Climate Change

First major fire of year destroys 3,000 hectares in Spain



(Last Updated On: March 25, 2023)

Spain’s first major wildfire of the year raged in the eastern Valencia region on Friday, destroying more than 3,000 hectares of forest and forcing 1,500 residents to abandon their homes, authorities said, Reuters reported.

An unusually dry winter across parts of the south of the European continent has reduced moisture in the soil and raised fears of a repeat of 2022, when 785,000 hectares were destroyed in Europe – more than double the annual average for the past 16 years, according to European Commission (EC) statistics.

“These fires we’re seeing, especially this early in the year, are once again proof of the climate emergency that humanity is living through, which particularly affects and ravages countries such as ours,” Spanish Prime Minister Pedro Sanchez told a news conference in Brussels.

In Spain, 493 fires destroyed a record 307,000 hectares of land last year, according to the Commission’s European Forest Fire Information System.

More than 500 firefighters supported by 18 planes and helicopters worked throughout the night and on Friday to tackle the blaze near the village of Villanueva de Viver, in the Valencia region.

Emergency services evacuated eight communities, said Gabriela Bravo, the regional head of interior affairs.

“We didn’t sleep well because of anxiety, wondering whether our home had burned down and thinking about the animals we have,” said Maria Antonia Montalaz, who was evacuated from nearby Montanejos.

While firefighters believed they were managing to control the spread of the flames, strong winds and “practically summertime temperatures” could reactivate it, Bravo said.

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