The Portland city skyline is shrouded in haze as a pedestrian walks along the Back Cove Trail on Tuesday morning. Ben McCanna/Staff Photographer

Wildfire smoke that blew in from Canada created unhealthy conditions for some people in Maine Tuesday.

The smoky haze is expected to ease Wednesday as the plume continues to move across the region. But a Maine scientist says we should expect more days of poor air quality in the future as a result of climate change.

“Will this become more common? It is likely,” said Gail Carlson, associate professor of environmental studies at Colby College. “What we are seeing are climate change impacts in the here and now. It’s important for people to realize that climate change is happening, and it’s affecting us now. This is not something far off in the future, or something that happens only in areas of high vulnerability. This is happening to all of us.”

Smoky conditions from nearly 900 wildfires raging across Canada are causing poor air quality in much of the United States, pushing through the Midwest before blowing into New England this week. Plumes of wildfire smoke in June largely missed Maine but created poor air quality conditions for more than 120 million Americans, including residents of New York City, which was enveloped in an orange-hued haze.

Maine’s air quality in most of the state dipped to levels that were dangerous for those with chronic health conditions on Tuesday. Air quality was in the “orange” category, which meant that the air was “unhealthy for sensitive groups,” according to the Maine Department of Environmental Protection.

Pollution levels did not reach so high in Maine Tuesday that most people were advised to stay indoors, something that other states have advised this summer.

Martha Webster, air quality meteorologist with the Maine DEP, said smoke levels peaked Tuesday morning. Portions of western Maine remained in the “orange” category Tuesday afternoon, while most of the state saw air quality improve to the “moderate” or “yellow” range.

“The wind began to pick up off the ocean in the late morning and Tuesday afternoon, pushing that plume northward,” Webster said.

More smoke is expected to push into Maine Wednesday, but the smoke is not as dense and air quality is expected to remain at the “moderate” level.

The Portland city skyline is shrouded in haze as a group of cyclists ride on Baxter Boulevard on Tuesday morning. Ben McCanna/Staff Photographer

Carlson said climate change driven by the burning of fossil fuels has resulted in more droughts, leading to more forest fires in dry areas.

“You end up with very dry vegetation, coupled with warm temperatures, and then you get these unplanned wildfires,” Carlson said. “Climate change has fueled the frequency and severity of wildfire season, and the season lasts longer.”

The fact that Maine missed the worst of the wildfire smoke last month had nothing to do with Maine’s geography or climate. The state was merely lucky that prevailing winds in June kept the smoke away from the state, Carlson said.

Carlson said this year’s wildfires affecting much of the continent are an “extreme” event that may have helped raise awareness that climate change is happening now.

Particulate matter from wildfire smoke contains volatile organic compounds, some of which are carcinogenic, and also can cause a host of other health problems.

A milky, hazy sky hangs above Portland on Tuesday as Pat Woodbury, left, and Alan Mancini, of South Portland, watch boats in the harbor from their lawn chairs in Bug Light Park. Ben McCanna/Staff Photographer

“They can impair breathing, interfere with the immune function of the lungs, exacerbate underlying cardiovascular or respiratory conditions, worsen asthma,” Carlson said. Long-term exposure also can cause chronic obstructive pulmonary disease, or COPD, and is linked to poor mental health and pregnancy complications, she said.

But Carlson said it’s not too late for society to improve air quality through a number of measures, such as greater use of electric vehicles and transitioning to clean energy, such as solar and wind power, and replacing fossil fuel systems of home heating with clean energy systems, such as replacing oil heating with heat pumps.

“Maine has a very ambitious climate plan, that is going to help and it is already helping,” Carlson said.