Amazônia Ocidental é região mais poluída do mundo, aponta monitoramento

 

Fumaça de incêndios florestais colocaram região a frente de países como Índia, Paquistão e China, em termos de poluição 

 Guilherme Gamada CNN , em São Paulo

 No último mês, a Amazônia Ocidental passou a ser a região mais poluída do mundo, segundo a plataforma suíça de monitoramento do ar, IQAir. Os incêndios florestais intensificam a emissão de poluentes e a média de concentração de material particulado colocou a região à frente de países como Índia, Paquistão e China — que historicamente enfrentam problemas com a qualidade do ar.

 

Os meses de setembro e outubro tradicionalmente registram picos na poluição do ar na maioria das cidades do Brasil devido aos incêndios na Amazônia. Entretanto, os dados enviados a pedido da CNN mostram que, neste ano, cidades têm registrado índices de poluição acima da média para o mês de agosto.

Em Rondônia, a capital Porto Velho (RO) teve o mês de agosto deste ano quatro vezes mais poluído do que no ano passado. O ar do município foi classificado como “perigoso”, grau mais alto de poluição, por sete dias.

 

Nesta quinta-feira (05), a cidade está na faixa “muito insalubre”, com níveis de poluentes quase 36 vezes maiores do que o recomendado pela Organização Mundial da Saúde (OMS), de 5 µg/m3 (microgramas por metro cúbico).

O corredor de fumaça dos incêndios florestais leva a nuvem de poluição a centenas de quilômetros de distância do foco das queimadas. A cidade de São Paulo registrou um mês mais poluído para a média, assim como o Rio de Janeiro, que teve o ar duas vezes pior do que no ano passado.

 

No Acre, Rio Branco (AC), também registrou índices duas vezes piores do que em comparação com agosto do ano passado. O município era a capital mais poluída do Brasil nesta quarta-feira (4), com níveis mais de 26 vezes acima do recomendado.

A IQAir prevê que Porto Velho (RO), siga com o ar de “Insalubre” a “Muito Insalubre” nas próxima semana. O calor e a baixa umidade do ar agravam os efeitos da poluição atmosférica.

Canada’s 2023 wildfires produced nearly a decade’s worth of blaze emissions

 

 

The health impacts from last year’s fires will also continue to be felt for decades. Photograph: Noah Berger/AP

 

 

 Fires made at least three times more likely by climate crisis and emitted about 2bn tonnes of CO2, data reveals.

 

Canada’s “record-shattering” wildfires last year produced nearly as much greenhouse gas emissions in one season as would be expected over a decade of fires in normal circumstances, data has shown.

The fires, in Canada’s “wildest season ever”, were made at least three times more likely by the climate crisis, and produced about 2bn tonnes of CO₂, about a quarter of the total global emissions from wildfires last year, according to data in the State of Wildfires report, published on Wednesday.

The health impacts from last year’s fires will also continue to be felt for decades.

Carbon dioxide from wildfires is a growing source of greenhouse gas emissions globally, reaching about 8.6bn tonnes last year, considerably more than the 4.8bn annual emissions of the US from all sources. However, the net impact of fires is likely to be reduced by the regrowth of vegetation taking up carbon from the atmosphere.

Matthew Jones, a research fellow at the Tyndall Centre for Climate Change Research at the University of East Anglia, and lead author of the report, warned that damage from intensifying wildfires would continue to increase unless the world succeeded in bringing down greenhouse gas emissions. Wildfires not only kill people, wildlife and livestock, and devastate trees and other landscapes, but can cause widespread and dangerous air pollution.

They are also an increasingly important contributor to the climate crisis, through their greenhouse gas emissions and destruction of carbon stored in vegetation and soil.

“These fires are something we should all be concerned about,” he said. “The full effects of last year’s fires will not be seen for a long time.”

Huge wildfires sweep across British Columbia 

 Canada’s fires, with a burned area that was six times greater than the average year, were some of last year’s worst. Brazil’s Amazonas state also had record highs, owing to a severe drought, while fires in Hawaii and Texas killed more than 100 people. The biggest single fire ever recorded in the EU burned 900 sq km of Greece.

However, lower than usual levels of burning in African savannah meant the greenhouse gas emissions from wildfires last year were only 16% above average – if savannahs had burned at their usual rate, rather than experiencing such relative calm, last year would have set a new record.

Separate data from the World Resources Institute showed that in 2023 nearly 12m hectares were burned by forest fires, an area roughly the size of Nicaragua, which was about a quarter more than the previous record in 2016. Between 2001 and 2023, the area burned has increased by about 5.4% a year, with the result that forest fires now result in nearly 6m more hectares of tree cover loss a year than they did in 2001 – an area roughly the size of Croatia.

Fires require not just high temperatures, but also an abundance of dry vegetation, and some form of ignition – either human or natural – to start and to continue burning fiercely. Cutting greenhouse gas emissions must be the biggest priority to prevent more wildfires in future, the authors said, but better land management and early warning systems could also help.

Banning people from setting fires, creating fire breaks and boundaries, and managing agricultural and forested areas in such a way as to reduce the amount of dry brush that provides fuel for fires, are also important. Providing masks and ventilation can also reduce the air pollution impact.

Early warning systems can be limited, however – in many hot areas there is a high likelihood of fire for most of the summer season.

“Wildfires are becoming more frequent and intense as the climate warms, and both society and the environment are suffering from the consequences,” said Jones.

Although wildfires occur naturally in many of the world’s hot regions, the effects of the climate crisis on their frequency and severity are now clear, according to the report. Human-driven changes to the climate made fires three times more likely in Canada, 20 times more likely in western Amazonia, and twice as likely in Greece.

As greenhouse gas emissions continue to mount, bigger fires can be expected. The researchers found that a Canadian born today would be more likely than not to experience another fire of similar magnitude to last year’s inferno within their lifetime, compared with a one in 10 chance of seeing such a fire for someone born in the 1940s.

Even wetlands and moist rainforests are now at high risk of fire, as unprecedented drought has taken hold. Brazil’s Pantanal region was devastated in June by record-breaking fires, which laid waste to globally important wildlife habitats.

Although regrowing forests can absorb carbon dioxide from the air as they develop – creating a “delayed carbon sink” – the shifts to more frequent fires are creating a worrying trend, where vegetation has less chance to recover, Jones added. This is making fires an increasing source of carbon in the atmosphere.

“The real problem begins when you have a shift in the fire regime away from its natural state and towards more frequent and severe burning. Unfortunately, that’s exactly what we’re seeing in forests, and it’s resulting in an imbalance – immediate emissions from forest fires this decade are increasingly outweighing the delayed sinks from fires in previous decades,” he said.

The State of Wildfires report 2023-24, published in the journal Earth System Science Data, was led by the University of East Anglia, the UK Centre for Ecology and Hydrology, and the Met Office, with the help of a broad network of researchers and institutions around the world. Scientists used global satellite observations, computer models and research from regional experts to compile the data.

Climate-Related Death of Coral Around World Alarms Scientists

                                         

NYtimes 

SYDNEY, Australia — Kim Cobb, a marine scientist at the Georgia Institute of Technology, expected the coral to be damaged when she plunged into the deep blue waters off Kiritimati Island, a remote atoll near the center of the Pacific Ocean. Still, she was stunned by what she saw as she descended some 30 feet to the rim of a coral outcropping.

“The entire reef is covered with a red-brown fuzz,” Dr. Cobb said when she returned to the surface after her recent dive. “It is otherworldly. It is algae that has grown over dead coral. It was devastating.”

The damage off Kiritimati is part of a mass bleaching of coral reefs around the world, only the third on record and possibly the worst ever. Scientists believe that heat stress from multiple weather events including the latest, severe El Niño, compounded by climate change, has threatened more than a third of Earth’s coral reefs. Many may not recover.

Coral reefs are the crucial incubators of the ocean’s ecosystem, providing food and shelter to a quarter of all marine species, and they support fish stocks that feed more than one billion people. They are made up of millions of tiny animals, called polyps, that form symbiotic relationships with algae, which in turn capture sunlight and carbon dioxide to make sugars that feed the polyps.

An estimated 30 million small-scale fishermen and women depend on reefs for their livelihoods, more than one million in the Philippines alone. In Indonesia, fish supported by the reefs provide the primary source of protein.

“This is a huge, looming planetary crisis, and we are sticking our heads in the sand about it,” said Justin Marshall, the director of CoralWatch at Australia’s University of Queensland.

Bleaching occurs when high heat and bright sunshine cause the metabolism of the algae — which give coral reefs their brilliant colors and energy — to speed out of control, and they start creating toxins. The polyps recoil. If temperatures drop, the corals can recover, but denuded ones remain vulnerable to disease. When heat stress continues, they starve to death.

Damaged or dying reefs have been found from Réunion, off the coast of Madagascar, to East Flores, Indonesia, and from Guam and Hawaii in the Pacific to the Florida Keys in the Atlantic.

The largest bleaching, at Australia’s Great Barrier Reef, was confirmed last month. In a survey of 520 individual reefs that make up the Great Barrier Reef’s northern section, scientists from Australia’s National Coral Bleaching Task Force found only four with no signs of bleaching. Some 620 miles of reef, much of it previously in pristine condition, had suffered significant bleaching.

In follow-up surveys, scientists diving on the reef said half the coral they had seen had died. Terry Hughes, the director of the Center of Excellence for Coral Reef Studies at James Cook University in Queensland, who took part in the survey, warned that even more would succumb if the water did not cool soon.

     

                                   

“There is a good chance a large portion of the damaged coral will die,” he added.

Scientists say the global bleaching is the result of an unusual confluence of events, each of which raised water temperatures already elevated by climate change.

In the North Atlantic, a strong high-pressure cell blocked the normal southward flow of polar air in 2013, kicking off the first of three warmer-than-normal winters in a row as far south as the Caribbean.

A large underwater heat wave formed in the northeastern Pacific in early 2014, and has since stretched into a wide band along the west coast of North America, from Baja California to the Bering Sea. Nicknamed the Blob, it is up to four degrees Fahrenheit warmer than surrounding waters, and has been blamed for a host of odd phenomena, including the beaching of hungry sea lions in California and the sighting of tropical skipjack tuna off Alaska.

Then came 2015, with the most powerful El Niño climate cycle in a century. It blasted heat across the tropical and southern Pacific, bleaching reefs from Kiritimati to Indonesia, and across the Indian Ocean to Réunion and Tanzania on Africa’s east coast.

“We are currently experiencing the longest global coral bleaching event ever observed,” said C. Mark Eakin, the Coral Reef Watch coordinator at the National Oceanic and Atmospheric Administration in Maryland. “We are going to lose a lot of the world’s reefs during this event.”

Reefs that take centuries to form can be destroyed in weeks. Individual corals may survive a bleaching, but repeated bleachings can kill them.

Lurid reports of damaged reefs started coming in from worried scientists in the summer of 2014.

Lyza Johnston, a marine biologist in the Northern Mariana Islands, dived to the reefs off Maug, a group of small islands: “In every direction, nearly all of the corals were bright white.”

Misaki Takabayashi, a marine scientist at the University of Hawaii at Hilo, surfed the waves above the blue rice coral there: “I could see what looked like bleached white ghosts popping up off the ocean floor at me.”

Cory Walter, a senior biologist at the Mote Marine Laboratory in Florida, peered down from a boat over Wonderland Reef off the Lower Florida Keys: “It almost looks like it snowed on the reef.”

Predicting the duration of the bleaching or forecasting the next one is difficult. The Blob has cooled somewhat, and El Niño, while weakening, is expected to stretch into 2017.

Dr. Eakin, the coral-reef specialist at the National Oceanic and Atmospheric Administration, said he expected the bleaching to continue for nine more months. Scientists will not be able to measure the full extent of the damage until it is over.

         

                                       

What is clear is that these events are happening with increasing frequency — and ferocity. The previous bleachings, in 2010 and 1998, do not appear to have been as extensive or prolonged as the current one.

The 1998 bleaching, which Dr. Eakin said had been set off by a fierce El Niño, killed around 16 percent of the world’s coral. By 2010, oceans had warmed enough that it took only a moderate El Niño to start another round.

Then in 2013, Dr. Eakin said, “a lot of bleaching happened due to climate change, before the El Niño had even kicked in.”

Reefs that were bleached in 2014, like those in the Florida Keys and the Caribbean, had no time to regenerate before suffering further thermal stress from El Niño last year, leaving the coral vulnerable to disease and death.

The reefs in the Florida Keys “are about to go into a third year straight of bleaching, something that has never happened before,” said Meaghan Johnson, a marine scientist at the Nature Conservancy. “We are worried about disease and mortality rates.”

Ove Hoegh-Guldberg, the director of Australia’s Global Change Institute, noted that 2015 was the hottest year ever recorded, both on land and in the oceans — breaking a record set just the year before.

“Rising temperatures due to climate change have pushed corals beyond their tolerance levels,” he said, adding that back-to-back bleaching can be particularly deadly to the corals.

El Niño warms the equatorial waters around Kiritimati Island more than anywhere else in the world, making it a likely harbinger for the health of reefs worldwide. That is why Dr. Cobb, the Georgia Tech scientist who made the recent dive, has been making the trek at least once a year for the past 18 to the tiny atoll, part of the Line Islands archipelago.

Though the atoll sits just north of the Equator, trade winds suck water up from the depths of the ocean, usually keeping the water temperature surrounding the reefs a healthy, nearly constant 78 degrees.

But in 2015, the expected upwelling of deep, cold water did not happen, Dr. Cobb said, speaking by satellite phone after her dive. So water in the atoll was 10 degrees warmer than normal, and never cooled enough to allow coral to recover.

“The worst has happened,” she said. “This shows how climate change and temperature stresses are affecting these reefs over the long haul. This reef may not ever be the same.”