Curbing air pollution could prevent millions of deaths in North America over next 50 years

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Curbing climate change and improving air quality could provide greater health benefits in our lifetime than previously thought, potentially preventing millions of deaths and hospitalizations in the U.S. alone during the next half-century, new research suggests.

The paper from a team at Duke University in Durham, N.C., was published in the peer-reviewed scientific journal PNAS on Monday. It is based on an analysis of more than 40 studies on air pollution and human health, coupled with climate modelling and simulations available through NASA.

The researchers found that, over the next 50 years, limiting global warming to no more than 2 C could prevent roughly 4.5 million premature deaths and several million more hospitalizations and emergency room visits across the U.S. â€" when compared to a scenario where climate change is left "largely unmitigated."

Those rapid, short-term benefits stem primarily from air quality improvements and outweigh any associated costs, the researchers wrote. They estimated this could lead to "tens of trillions of dollars" in benefits from avoided deaths.

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Lead author Drew Shindell, a professor in the division of earth and climate sciences at Duke University, said he was surprised the results "were just so enormous."

"We think of our air as being relatively clean in North America," he said. "And so one of the things I think is so incredible is how many people are still affected by our air quality, even though it's so much better than it was decades ago."

The striking predictions, according to Shindell, suggest human actions to curb air pollution now can make a difference in both the long and short term.

"Fewer children going to the hospital with asthma attacks, fewer elderly people dying of respiratory illnesses or heart attacks," he said.

"I think most anywhere that takes action to mitigate climate change can expect to see enormous benefits very, very rapidly … if the whole world co-operates, then of course, we also solve the climate crisis."

WATCH | Improving air quality could prevent millions of deaths in North America:

Curbing climate change could prevent millions of deaths, research suggests20 hours agoA new study suggests reducing carbon emissions and improving air quality could prevent millions of deaths and hospitalizations in the U.S. alone within 50 years. 2:05 Health benefits 'larger' than previously estimated

Climate change mitigation, the new paper noted, "involves a global transition to low carbon energy, energy efficiency, low demand for carbon-intensive goods and services, and a reduction in emissions of non-CO2 climate-altering pollutants."

The research was published while global leaders are gathering in Glasgow for the COP26 climate summit, which has a key goal to "secure global net zero by mid-century and keep 1.5 degrees within reach."

The Conference of Parties (COP), as it's known, meets every year and is the global decision-making body set up in the early 1990s to implement the United Nations Framework Convention on Climate Change and subsequent climate agreements.

On Monday during the summit, Prime Minister Justin Trudeau announced Canada will impose a hard cap on emissions from the oil and gas sector, in hopes of curbing the growth of one of the country's largest industries to help hit that global goal.

The target is rooted in the 2015 Paris Agreement, when close to 200 countries committed to cutting greenhouse gas emissions in order to limit global warming to well below 2 C â€" and preferably below 1.5 C â€" compared to the pre-industrial era.

The Duke University analysis incorporated those targets, and while it was centred on only one country, both Shindell and outside climate researchers who weren't connected with the study say there are takeaways for the rest of the world â€" Canada included.

"Addressing the climate crisis in Canada means eliminating the use of fossil fuels within decades. So when we do that, we get those same kinds of benefits that they found in this U.S. study," said Laura Tozer, an assistant professor of environmental studies at the University of Toronto.

Addressing the climate crisis in Canada means getting the same kinds of benefits observed in a recent U.S. study, says Laura Tozer, an assistant professor of environmental studies at the University of Toronto. (Lauren Pelley/CBC)

A rapid shift to a 2 C pathway could reduce the premature death toll tied to air pollution by 40 per cent in just a decade, the research team found, with broader health benefits of cleaner air "far larger than previously estimated" when it comes to reducing hospitalizations and emergency visits tied to respiratory conditions.

Hitting that target could also maintain productivity and prevent major crop losses, the paper continued.

"Considering these additional benefits of emissions reductions, benefits outweigh costs even in the near-term," the authors wrote.

Ian Mauro, executive director of the Prairie Climate Centre, called the paper a "breakthrough" study that overturns notions of climate change being a long-term, global issue, as opposed to one where rapid, regional initiatives can spark better outcomes in the not-so-distant future.

"This study actually shows when you take local action, there are local benefits that contribute to solving that global problem," he said. "It starts with cities, it starts with towns, it starts with big industry."

High school students from across Montreal march down Parc Avenue as part of a worldwide day of protest against climate change in 2019. The banner, '1.5 to stay alive,' refers to what scientists say is the maximum number of degrees the global temperature can rise by the end of this century to avoid the worst impacts of climate change. (Louise Gravel/Radio-Canada) Canada already facing climate change impacts

Throughout Canada, the influence of climate change on people's health and well-being is already being felt at a local level, even beyond the direct impact of air pollution.

In the Maritimes, coastal towns are now vulnerable to fierce storms and rising sea levels, with the ocean potentially rising up to 2.5 metres around Nova Scotia within the next 80 years.

In Western Canada, communities have been ravaged by wildfires. Roughly 1,600 fires burned nearly 8,700 square kilometres of land this year in B.C. alone, as a "heat dome" claimed 595 lives, set scorching temperature records and burned down the town of Lytton within minutes.

And in the North, rapidly melting permafrost is threatening people's livelihoods, elevating the risk of wildfires and flood warnings, and releasing toxic mercury that's now showing up in slightly elevated levels in whitefish, a dietary staple in some communities. 

"Mercury is kind of the zenith of the number one quantifiable physical health-altering issue that we can see with climate change right now," said Chief Dana Tizya-Tramm, of the Vuntut Gwitchin First Nation in northern Yukon.

A motorist watches from a pullout on the Trans-Canada Highway as a wildfire burns on the side of a mountain in Lytton, B.C., July 1, 2021. (Darryl Dyck/The Canadian Press)

Avoiding those kinds of dire impacts should be a pressing concern for governments of all levels, experts and advocates warn.

But while Shindell's research showed clear short-term health and economic benefits of mitigating climate change, he acknowledged his team's forward-looking approach does enter "uncharted territory."

The modelling was meant to offer a middle-of-the-road look at a range of potential scenarios, though determining specific local outcomes can be trickier. Still, he said, it offers a hopeful take on what's possible within our lifetimes.

"We often hear in climate change that it's expensive to do something," said Shindell. "But it's more expensive not to do anything."

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