BILLINGS, Mont. (AP) — Climate change in the Western U.S. means more intense and frequent wildfires churning out waves of smoke that scientists say will sweep across the continent to affect tens of millions of people and cause a spike in premature deaths.

That emerging reality is prompting people in cities and rural areas alike to prepare for another summer of sooty skies along the West Coast and in the Rocky Mountains — the regions widely expected to suffer most from blazes tied to dryer, warmer conditions.

“There’s so little we can do. We have air purifiers and masks — otherwise we’re just like ‘Please don’t burn,’” said Sarah Rochelle Montoya of San Francisco, who fled her home with her husband and children last fall to escape thick smoke enveloping the city from a disastrous fire roughly 150 miles (241 kilometers) away.

Other sources of air pollution are in decline in the U.S. as coal-fired power plants close and fewer older cars roll down highways. But those air quality gains are being erased in some areas by the ill effects of massive clouds of smoke that can spread hundreds and even thousands of miles on cross-country winds, according to researchers.

With the 2019 wildfire season already heating up and fires breaking out from Southern California through Canada to Alaska, authorities are scrambling to better protect the public before smoke again blankets cities and towns. Officials in Seattle recently announced plans to retrofit five public buildings as smoke-free shelters.

Scientists from NASA and universities are refining satellite imagery to predict where smoke will travel and how intense it will be. Local authorities are using those forecasts to send out real-time alerts encouraging people to stay indoors when conditions turn unhealthy.

The scope of the problem is immense: Over the next three decades, more than 300 counties in the West will see more severe smoke waves from wildfires, sometimes lasting weeks longer than in years past, according to atmospheric researchers led by a team from Yale and Harvard.

For almost two weeks last year during the Camp Fire , which killed 85 people and destroyed 14,000 homes in Paradise, California, smoke from the blaze inundated the San Francisco neighborhood where Montoya lives with her husband, Trevor McNeil, and their three children.

Lines formed outside hardware stores as people rushed to buy face masks and indoor air purifiers. The city’s famous open air cable cars shut down. Schools kept children inside or canceled classes, and a church soup kitchen sheltered homeless people from the smoke.

Montoya’s three children have respiratory problems that their doctor says is likely a precursor to asthma, she said. That would put them among those most at-risk from being harmed by wildfire smoke, but the family was unable to find child-sized face masks or an adequate air filter. Both were sold out everywhere they looked.

In desperation, her family ended up fleeing to a relative’s vacation home in Lake Tahoe. The children were delighted that they could go outside again.

“We really needed our kids to be able to breathe,” Montoya said.

Smoke from wildfires was once considered a fleeting nuisance except for the most vulnerable populations. But it’s now seen in some regions as a recurring and increasing public health threat, said James Crooks, a health investigator at National Jewish Health, a Denver medical center that specializes in respiratory ailments.

“There are so many fires, so many places upwind of you that you’re getting increased particle levels and increased ozone from the fires for weeks and weeks,” Crooks said.

One such place is Ashland, Oregon, a city of about 21,000 known for its summer-long Oregon Shakespeare Festival.

During each of the past two summers, Ashland had about 40 days of smoke-filled air, said Chris Chambers, wildfire division chief for the fire department. Last year, that forced cancellation of more than two-dozen outdoor performances. Family physician Justin Adams said the smoke was hardest on his patients with asthma and other breathing problems and he expects some to see long-term health effects.

“It was essentially like they’d started smoking again for two months,” he said.

Voters in 2018 approved a bond measure that includes money to retrofit Ashland schools with “scrubbers” to filter smoke. Other public buildings and businesses already have them. A community alert system allows 6,500 people to receive emails and text messages when the National Weather Service issues smoke alerts.

“We really feel like we’ve made a conscious effort to adapt to climate change,” Chambers said. “But you can’t just live your whole life inside.”

The direct damage from conflagrations that regularly erupt in the West is stark. In California alone, wildfires over the past two years torched more than 33,000 houses, outbuildings and other structures and killed 146 people.

Harder to grasp are health impacts from microscopic particles in the smoke that can trigger heart attacks, breathing problems and other maladies. The particles, about 1/30th of the diameter of a human hair, penetrate deeply into the lungs to cause coughing, chest pain and asthma attacks. Children, the elderly and people with lung diseases or heart trouble are most at risk.

Death can occur within days or weeks among the most vulnerable following heavy smoke exposure, said Linda Smith, chief of the California Air Resources Board’s health branch.

Over the past decade as many as 2,500 people annually died prematurely in the U.S. from short-term wildfire smoke exposure, according to Environmental Protection Agency scientists.

The long-term effects have only recently come into focus, with estimates that chronic smoke exposure causes about 20,000 premature deaths per year, said Jeff Pierce, an associate professor of atmospheric science at Colorado State University.

That figure could double by the end of this century due to hotter, drier conditions and much longer fire seasons, said Pierce.

His research team compared known health impacts from air pollution against future climate scenarios to derive its projections. The results suggested smoke will spread to become a dominant pollutant even in areas not typically associated with wildfires, such as the South and Northeast.

Even among wildfire experts, understanding of health impacts from smoke was elusive until recently. But attitudes shifted as growing awareness of climate change ushered in research examining wildfire’s potential consequences.

Residents of Northern California, western Oregon, Washington state and the Northern Rockies are projected to suffer the worst increases in smoke exposure, according to Loretta Mickley, a senior climate research fellow at Harvard University.

“It’s really incredible how much the U.S. has managed to clean up the air from other (pollution) sources like power plants and industry and cars,” Mickley said. “Climate change is throwing a new variable into the mix and increasing smoke, and that will work against our other efforts to clear the air through regulations. This is kind of an unexpected source of pollution and health hazard.”

___

Follow Matthew Brown on Twitter at https://twitter.com/MatthewBrownAP

BILLINGS, Mont. (AP) — Climate change in the Western U.S. means more intense and frequent wildfires churning out waves of smoke that scientists say will sweep across the continent to affect tens of millions of people and cause a spike in premature deaths.

That emerging reality is prompting people in cities and rural areas alike to gird themselves for another summer of sooty skies along the West Coast and in the Rocky Mountains — the regions widely expected to suffer most from blazes tied to dryer, warmer conditions.

“There’s so little we can do. We have air purifiers and masks — otherwise we’re just like ‘Please don’t burn,’” said Sarah Rochelle Montoya of San Francisco, who fled her home with her husband and children last fall to escape thick smoke enveloping the city from a disastrous fire roughly 150 miles (241 kilometers) away.

Other sources of air pollution are in decline in the U.S. as coal-fired power plants close and fewer older cars roll down highways. But those air quality gains are being erased in some areas by the ill effects of massive clouds of smoke that can spread hundreds and even thousands of miles on cross-country winds, according to researchers.

With the 2019 fire season already heating up with fires from southern California to Canada, authorities are scrambling to better protect the public before smoke again blankets cities and towns. Officials in Seattle recently announced plans to retrofit five public buildings as smoke-free shelters.

Scientists from NASA and universities are refining satellite imagery to predict where smoke will travel and how intense it will be. Local authorities are using those forecasts to send out real-time alerts encouraging people to stay indoors when conditions turn unhealthy.

The scope of the problem is immense: Over the next three decades, more than 300 counties in the West will see more severe smoke waves from wildfires, sometimes lasting weeks longer than in years past, according to atmospheric researchers led by a team from Yale and Harvard.

For almost two weeks last year during the Camp Fire, which killed 85 people and destroyed 14,000 homes in Paradise, California, smoke from the blaze inundated the San Francisco neighborhood where Montoya lives with her husband, Trevor McNeil, and their three children.

Lines formed outside hardware stores as people rushed to buy face masks and indoor air purifiers. The city’s famous open air cable cars shut down. Schools kept children inside or canceled classes, and a church soup kitchen sheltered homeless people from the smoke.

Montoya’s three children have respiratory problems that their doctor says is likely a precursor to asthma, she said. That would put them among those most at-risk from being harmed by wildfire smoke, but the family was unable to find child-sized face masks or an adequate air filter. Both were sold out everywhere they looked.

In desperation, her family ended up fleeing to a relative’s vacation home in Lake Tahoe. The children were delighted that they could go outside again.

“We really needed our kids to be able to breathe,” Montoya said.

Smoke from wildfires was once considered a fleeting nuisance except for the most vulnerable populations. But it’s now seen in some regions as a recurring and increasing public health threat, said James Crooks, a health investigator at National Jewish Health, a Denver medical center that specializes in respiratory ailments.

“There are so many fires so many places upwind of you that you’re getting increased particle levels and increased ozone from the fires for weeks and weeks,” Crooks said.

One such place is Ashland, Oregon, a city of about 21,000 known for its summer-long Oregon Shakespeare Festival.

During each of the past two summers, Ashland had about 40 days of smoke-filled air, said Chris Chambers, wildfire division chief for the fire department. Last year that forced cancellation of more than two-dozen outdoor performances. Family physician Justin Adams said the smoke was hardest on his patients with asthma and other breathing problems and he expects some to see long-term health effects.

“It was essentially like they’d started smoking again for two months,” he said.

Voters in 2018 approved a bond measure that includes money to retrofit Ashland schools with “scrubbers” to filter smoke. Other public buildings and businesses already have them. A community alert system allows 6,500 people to receive emails and text messages when the National Weather Service issues smoke alerts.

“We really feel like we’ve made a conscious effort to adapt to climate change,” Chambers said. “But you can’t just live your whole life inside.”

The direct damage from conflagrations that regularly erupt in the West is stark. In California alone, wildfires over the past two years torched more than 33,000 houses, outbuildings and other structures and killed 146 people.

Harder to grasp are health impacts from microscopic particles in the smoke that can trigger heart attacks, breathing problems and other maladies. The particles, about 1/30th of the diameter of a human hair, penetrate deeply into the lungs to cause coughing, chest pain and asthma attacks. Children, the elderly and people with lung diseases or heart trouble are most at risk.

Death can occur within days or weeks among the most vulnerable following heavy smoke exposure, said Linda Smith, chief of the California Air Resources Board’s health branch.

In the past decade as many as 2,500 people annually died prematurely in the U.S. from short-term wildfire smoke exposure, according to Environmental Protection Agency scientists.

The long-term effects have only recently come into focus, with estimates that chronic smoke exposure is causing on the order of 20,000 premature deaths per year, said Jeff Pierce, an associate professor of atmospheric science at Colorado State University. That figure could double by the end of this century due to hotter, dryer conditions and much longer fire seasons, said Pierce. His research team compared known health impacts from air pollution against future climate scenarios to derive its projections.

Even among wildfire experts, understanding of health impacts from smoke was elusive until recently. But attitudes shifted as growing awareness of climate change ushered in research examining wildfire’s potential consequences.

Residents of Northern California, western Oregon, Washington state and the Northern Rockies are projected to suffer the worst increases in smoke exposure, according to Loretta Mickley, a senior climate research fellow at Harvard.

“It’s really incredible how much the U.S. has managed to clean up the air from other (pollution) sources like power plants and industry and cars,” Mickley said. “Climate change is throwing a new variable into the mix and increasing smoke, and that will work against our other efforts to clear the air through regulations. This is kind of an unexpected source of pollution and health hazard.”

___

Follow Matthew Brown on Twitter at https://twitter.com/MatthewBrownAP .

When science teacher Diana Allen set out to teach climate change, a subject she’d never learned in school, she fell into a rabbit’s hole of misinformation: Many resources presented online as educational material were actually junk.

“It is a pretty scary topic to take on,” said Allen, a teacher at Sanford Junior High School, in southern Maine. “There are some pretty tricky websites out there. You kind of have to be an expert to be able to see through that like, ‘Oh, no, these guys aren’t telling you the truth.’”

There are materials produced by climate change doubters, lesson plans developed by the oil industry, and countless other sites with misleading or outdated information. The Climate Literacy and Energy Awareness Network , funded by federal grants, reviewed more than 30,000 free online resources and found only 700 acceptable for use in schools.

“There’s a lot of information that’s out there that is broken, old, misleading, not scientifically sound, not sound technically,” said Frank Niepold, a climate education coordinator at the National Oceanic and Atmospheric Administration.

The Heartland Institute, an Illinois-based group that dismisses climate change, in 2017 sent thousands of science teachers copies of a book titled “Why Scientists Disagree About Global Warming” The book, attributed to the group’s Nongovernmental International Panel on Climate Change, misrepresents the near-universal consensus of scientists and the United Nations’ Intergovernmental Panel on Climate Change that global warming is real and man-made.

Another resource, a set of six lesson plans on understanding climate change, is available online from the Canada-based Fraser Institute, which counts the Charles Koch Foundation among its financial supporters. The lessons claim that mainstream climate scientists have made selective use of data and that it’s a matter of debate whether human-generated carbon dioxide emissions have contributed to climate change, saying “the issues are far from settled.”

“Our history is full of examples where ‘common knowledge’ was discarded in favor of more correct hypotheses,” the lesson plans say. Among them, it lists, “Are diseases caused by evil spirits? Are natural disasters caused by angry gods?”

And: “Does smoking pose a threat to your health?”

Also vying for educators’ attention are classroom-ready materials made available by the oil companies. ExxonMobil, Chevron, Shell and other companies have invested heavily in promoting science, technology, engineering and math education in K-12 schools. Such materials are used widely to teach topics related to energy, but critics say they can mislead by not addressing the role of burning fossil fuels in global warming.

For teachers in cash-strapped schools, it can be hard to pass up the free handout materials.

Melissa Lau, a sixth-grade teacher in Piedmont, Oklahoma, attended one of the training sessions put on regularly for teachers by the Oklahoma Energy Resource Bureau, which is funded by the oil and gas companies. She kept the $50 stipend and the tub full of science equipment she got from the group but she tossed its illustrated lesson plans featuring the character “Petro Pete.”

In a book available online, Petro Pete has a nightmare about everything that would be missing from his life if there were no petroleum products, from his toothbrush to his school bus.

“I get free beakers and cool things like that,” Lau said. “But the curriculum itself is borderline propaganda.”

A spokeswoman for the industry group, Dara McBee, said their materials align with Oklahoma standards, which do not reference climate change, and they are intended to supplement what students learn in school.

Kevin Leineweber, a science teacher at Cascade High School in Clayton, Indiana, said he is skeptical about resources sent to him, including oil industry materials, but some colleagues are less so. At a districtwide science meeting a couple months ago one elementary school teacher expressed excitement about receiving unsolicited materials on climate change in the mail, to help introduce the topic to students. After talking it over with Leineweber, the teacher tossed the mailing of unknown origin.

“I’m just like, ‘Oh, jeez,’” Leineweber said.

The oil industry materials have the effect of pushing climate change to the periphery, Charles Anderson, a professor of science education at Michigan State University.

“The school systems of the country are so fragmented and under-resourced that they have no choice but to turn to people like the oil industry who offer them free stuff,” he said.

Climate change education varies across states, and often from one classroom to the next. The Next Generation Science Standards, which emphasize climate change and how humans are altering the planet, have been adopted by or served as a model for most states. But many teachers report that they shy away from the topic not only because of issues with materials but also the political sensitivities, and uncertainty over where to introduce an issue that crosses so many disciplines.

Diana Allen, 48, said she began to see it as her duty to teach climate change even though it’s not required under Maine’s science education standards.

For her lesson plans on climate change, she turns primarily to other teachers, pulling resources they have vetted and shared on an email thread overseen by the National Association of Science Teachers. Other teachers have turned to the National Center for Science Education, which posts free climate change lessons and has a ”scientist in the classroom ” program.

Many educators say that climate change as an area of instruction is still so new that textbook publishers have not caught up enough to provide useful materials.

“I have a Ph.D. from Stanford in biochemistry, and it’s still hard for me to source stuff that works in my classroom right,” said Kirstin Milks, an Earth science teacher at Bloomington High School South in Indiana.

Milks helps train educators on how to teach climate change. In their applications, many teachers display a sense of urgency in their applications, she said.

“I think we all are in that same boat of understanding that this might be one of the most important social justice issues of our time, one of the most important environmental issues of our time, one of the most important political issues of our time,” she said.

Sometimes educators have to push back against what their students are taught in other classrooms.

Leigh Foy, a science teacher at York Suburban High School in Pennsylvania, said a social studies teacher at her school has told students for years that climate change is a hoax and he could prove it with an experiment. He would fill a cup in the classroom with ice and water, mark the water level, and show students it didn’t rise as the ice melted. The problem, Foy said, is his lack of accounting for the difference between sea ice and land ice or the expansion of water as it gets warmer.

“This is just an example of what we’re up against,” Foy said.

Teachers who have gotten themselves up to speed on climate change often say they make it a primary goal to help their students identify untrustworthy materials.

Sarah Ott, who teaches physical science to eighth-graders in Dalton, Georgia, dedicates a section of her class to climate literacy. In one April class, she discussed how to identify misinformation, highlighting materials including a petition signed by more than 30,000 purported scientists that dismisses the dangers of global warming.

“These people are fake experts and this is being used to mislead people,” she told her students. “So we’re going to be learning about misinformation and ways for you to spot misinformation. And this is a great skill because you’re not just going to use this for science. You’re going to use this for all of your subjects.”

____

Associated Press writer Sarah Blake Morgan contributed to this report from Dalton, Georgia.

When science teacher Diana Allen set out to teach climate change, a subject she’d never learned in school, she fell into a rabbit’s hole of misinformation: Many resources presented online as educational material were actually junk.

“It is a pretty scary topic to take on,” said Allen, a teacher at Sanford Junior High School, in southern Maine. “There are some pretty tricky websites out there. You kind of have to be an expert to be able to see through that like, ‘Oh, no, these guys aren’t telling you the truth.’”

There are materials produced by climate change doubters, lesson plans developed by the oil industry, and countless other sites with misleading or outdated information. The Climate Literacy and Energy Awareness Network , funded by federal grants, reviewed more than 30,000 free online resources and found only 700 acceptable for use in schools.

“There’s a lot of information that’s out there that is broken, old, misleading, not scientifically sound, not sound technically,” said Frank Niepold, a climate education coordinator at the National Oceanic and Atmospheric Administration.

The Heartland Institute, an Illinois-based group that dismisses climate change, in 2017 sent thousands of science teachers copies of a book titled “Why Scientists Disagree About Global Warming” The book, attributed to the group’s Nongovernmental International Panel on Climate Change, misrepresents the near-universal consensus of scientists and the United Nations’ Intergovernmental Panel on Climate Change that global warming is real and man-made.

Another resource, a set of six lesson plans on understanding climate change, is available online from the Canada-based Fraser Institute, which counts the Charles Koch Foundation among its financial supporters. The lessons claim that mainstream climate scientists have made selective use of data and that it’s a matter of debate whether human-generated carbon dioxide emissions have contributed to climate change, saying “the issues are far from settled.”

“Our history is full of examples where ‘common knowledge’ was discarded in favor of more correct hypotheses,” the lesson plans say. Among them, it lists, “Are diseases caused by evil spirits? Are natural disasters caused by angry gods?”

And: “Does smoking pose a threat to your health?”

Also vying for educators’ attention are classroom-ready materials made available by the oil companies. ExxonMobil, Chevron, Shell and other companies have invested heavily in promoting science, technology, engineering and math education in K-12 schools. Such materials are used widely to teach topics related to energy, but critics say they can mislead by not addressing the role of burning fossil fuels in global warming.

For teachers in cash-strapped schools, it can be hard to pass up the free handout materials.

Melissa Lau, a sixth-grade teacher in Piedmont, Oklahoma, attended one of the training sessions put on regularly for teachers by the Oklahoma Energy Resource Bureau, which is funded by the oil and gas companies. She kept the $50 stipend and the tub full of science equipment she got from the group but she tossed its illustrated lesson plans featuring the character “Petro Pete.”

In a book available online, Petro Pete has a nightmare about everything that would be missing from his life if there were no petroleum products, from his toothbrush to his school bus.

“I get free beakers and cool things like that,” Lau said. “But the curriculum itself is borderline propaganda.”

A spokeswoman for the industry group, Dara McBee, said their materials align with Oklahoma standards, which do not reference climate change, and they are intended to supplement what students learn in school.

Kevin Leineweber, a science teacher at Cascade High School in Clayton, Indiana, said he is skeptical about resources sent to him, including oil industry materials, but some colleagues are less so. At a districtwide science meeting a couple months ago one elementary school teacher expressed excitement about receiving unsolicited materials on climate change in the mail, to help introduce the topic to students. After talking it over with Leineweber, the teacher tossed the mailing of unknown origin.

“I’m just like, ‘Oh, jeez,’” Leineweber said.

The oil industry materials have the effect of pushing climate change to the periphery, Charles Anderson, a professor of science education at Michigan State University.

“The school systems of the country are so fragmented and under-resourced that they have no choice but to turn to people like the oil industry who offer them free stuff,” he said.

Climate change education varies across states, and often from one classroom to the next. The Next Generation Science Standards, which emphasize climate change and how humans are altering the planet, have been adopted by or served as a model for most states. But many teachers report that they shy away from the topic not only because of issues with materials but also the political sensitivities, and uncertainty over where to introduce an issue that crosses so many disciplines.

Diana Allen, 48, said she began to see it as her duty to teach climate change even though it’s not required under Maine’s science education standards.

For her lesson plans on climate change, she turns primarily to other teachers, pulling resources they have vetted and shared on an email thread overseen by the National Association of Science Teachers. Other teachers have turned to the National Center for Science Education, which posts free climate change lessons and has a ”scientist in the classroom ” program.

Many educators say that climate change as an area of instruction is still so new that textbook publishers have not caught up enough to provide useful materials.

“I have a Ph.D. from Stanford in biochemistry, and it’s still hard for me to source stuff that works in my classroom right,” said Kirstin Milks, an Earth science teacher at Bloomington High School South in Indiana.

Milks helps train educators on how to teach climate change. In their applications, many teachers display a sense of urgency in their applications, she said.

“I think we all are in that same boat of understanding that this might be one of the most important social justice issues of our time, one of the most important environmental issues of our time, one of the most important political issues of our time,” she said.

Sometimes educators have to push back against what their students are taught in other classrooms.

Leigh Foy, a science teacher at York Suburban High School in Pennsylvania, said a social studies teacher at her school has told students for years that climate change is a hoax and he could prove it with an experiment. He would fill a cup in the classroom with ice and water, mark the water level, and show students it didn’t rise as the ice melted. The problem, Foy said, is his lack of accounting for the difference between sea ice and land ice or the expansion of water as it gets warmer.

“This is just an example of what we’re up against,” Foy said.

Teachers who have gotten themselves up to speed on climate change often say they make it a primary goal to help their students identify untrustworthy materials.

Sarah Ott, who teaches physical science to eighth-graders in Dalton, Georgia, dedicates a section of her class to climate literacy. In one April class, she discussed how to identify misinformation, highlighting materials including a petition signed by more than 30,000 purported scientists that dismisses the dangers of global warming.

“These people are fake experts and this is being used to mislead people,” she told her students. “So we’re going to be learning about misinformation and ways for you to spot misinformation. And this is a great skill because you’re not just going to use this for science. You’re going to use this for all of your subjects.”

____

Associated Press writer Sarah Blake Morgan contributed to this report from Dalton, Georgia.