Smoke in New York: climate change increases frequency – 06/10/2023 – Environment

The smoke from forest fires in Canada, which covered New York, crossed the Atlantic and reached Norway, reinforces the warning of drier and hotter times with the arrival of El Niño. That’s because even in the last three years of La Ninã, with more rain in the neighboring United States, the fire spread ash across the continent.

The main reading is that the frequency of orange haze on the US east coast or dark days —as has already happened in São Paulo— will increase. The answer is nothing new: climate change is altering when and how intense these problems will be.

In western Amazonia, the gray cloud captured by satellite last year was caused by the worst fire month since 2010. Three years ago, the sky over San Francisco, on the US west coast, turned gray with particles that would also reach Europe.

In September 2020, the capital of São Paulo also had gray skies due to fires in the Midwest and North. The city had already had a darker day than usual in 2019, the year in which Sydney (Australia) experienced a similar situation.

The causes and reasons for the spread of fire are different around the world, but they work as a more feasible thermometer of what lies ahead. That’s what Ane Alencar, director of science at Ipam (Amazon Research Institute) says.

“It’s something peculiar in Canada. Both forests on the west and east coasts burned at about the same time, with big fires in the eastern part, which are usually smaller,” he says. “And they are only at the beginning of their burning season. The peak is in July, a little different than ours, in September.”

Alencar says that the formation of pockets of dry and hot air arrived earlier this year, favoring the spread of fire.

Furthermore, she states that the higher temperature in the waters of the Pacific, the ocean in which El Niño occurs, changes the circulation of winds and favors the spread of fire and soot, making it travel further.

“And if there’s a lot of fire on the west coast and east coast, there’s an air current that takes that smoke to the east coast of the US, ‘coming down’.

In Canada, half of forest fires are caused by lightning, but it also happens by carelessness like campfires, and more unusual practices, in the country, of plant suppression with fire.

In Brazil, one of the main risks for smoke to spread over cities is the use of this technique for pasture management.

“What New Yorkers face, breathing bad air due to wildfires, people in the Amazon go through even worse every year. What we don’t want is for this to happen again.”

A study published in April in the scientific journal Communications Earth & Environment managed to measure for the first time damage associated with fires in indigenous lands in the Legal Amazon and observed impacts on about 15 million cases of respiratory infections per year, with an estimated cost of US$ 2 billion (about BRL 9.76 billion).

For the researcher, Brazil needs to qualify the use of fire management in the Amazon forest and in other biomes, such as the cerrado and the Pantanal, because the current use, to clear deforested areas or pasture, tends to get more and more out of control.

“Climate changes are going to make this more and more frequent, both because of the stronger and more unpredictable relationship with El Niño and La Niña, and the impact on the entire climate circulation on the planet. It’s going to become common”, says Alencar. “Fire is going to be the main indicator of these extreme events.

In addition to signals, wildfires also have the potential to release large amounts of greenhouse gases. In 2021, fires in boreal forests in Eurasia and North America opened the way for 1.76 billion tonnes of CO₂ into the atmosphere, which accounted for 23% of all fire emissions in the world that year.

In the last three decades, Brazil has had almost 20% of its territory affected by fires, especially in the Amazon and cerrado.

According to Alencar, it is also necessary for the country to approve the national fire management policy to encourage regulations in states and municipalities.

The current project, from 2018, was approved in 2021 by the House and passed by the Environment Committee in the Senate in May of this year. The project creates rules for the use of fire in rural areas, including among traditional communities and indigenous peoples, and provides for its gradual replacement by other management techniques.

The Planeta em Transe project is supported by the Open Society Foundations.