You likely hear about climate change in the news on a regular basis and know it’s a top priority among some politicians, and certainly environmental activists.

But you may be less familiar with the direct impact this cycle can have on human health, including on people at risk for and living with allergies and asthma.

Here’s a little climate change 101: Rising temperatures lead to extreme weather, which increases ground-level ozone and air pollution, explained Melanie Carver, chief mission officer at the Allergy and Asthma Foundation of America (AAFA). This causes an increase in atmospheric carbon dioxide levels and rising temperatures again.

“Each of these steps has a direct impact on outdoor and indoor air quality,” said Carver, explaining that these effects can trigger and worsen respiratory illness and lead to more hospitalizations and premature death.

How Climate Change Affects Air Quality Indoors and Out

Climate change causes heat waves that trap air pollutants and increase ground-level ozone, drying out vegetation and providing more fuel for wildfires. By the end of the century, highly devastating fires could increase by up to 57% if emissions are left uncurbed, researchers estimate.

We already see the impact on human health. Exposure to wildfire smoke has been linked to lower lung function and increased use of asthma medications, Carver said. Rising temperatures, extreme heat, wildfire smoke, increased air pollution, and rising carbon dioxide, or CO₂, have all been associated with asthma-related emergency department visits as well. At the same time, extreme heat and air pollution exposure have been linked with premature death related to asthma.

The aforementioned factors can impact allergy seasons, too, Carver pointed out. When the snow melts, an itchy nose or eyes, and more sneezing, is probably part of your springtime routine. Nothing some over-the-counter allergy meds and tissues can’t fix, right? You’re not alone: Seasonal allergies affect about 7% of the U.S. population, including 19.2 million adults and 5.2 million children, according to the Centers for Disease Control and Prevention.

Pollen is a big trigger for seasonal allergies. Scientific data estimate 60% of individuals with asthma have allergic asthma, meaning their asthma is triggered by allergens such as pollen. Plus, an estimated 40% of people with environmental allergies are allergic to pollen, research suggests.

For asthma and allergy sufferers, research shows the impacts of climate change can extend pollen seasons. Since 1990, pollen seasons have lengthened on average by 20 days and have contained 21% more pollen, data show. Not only are pollen seasons getting longer, they are also getting worse. Carver said research shows extended pollen seasons have also resulted in increased allergenicity of pollen, exacerbating allergy and asthma symptoms.

Unfortunately, staying indoors isn’t the solution. Outdoor pollutants can infiltrate indoor environments and contribute to levels of indoor particulate matter, Carver said. What’s more, extreme precipitation, flooding and storms can lead to water damage, promoting a boost in mold, bacteria, and dust mites — all insidious to people with allergies and asthma.

Climate Change-Related Health Harms Don’t Affect All Groups Equally

While the harmful health effects of climate change can affect anyone, they impact certain groups disproportionately. “Structural racism, including community disinvestment, discriminatory housing practices, and inequities in funding and resource distribution, have led to low-income communities and communities of color being disproportionately impacted by the health impacts of climate change,” Carver said.

Black individuals in the United States are more likely to live in neighborhoods with few trees and more heat-trapping pavement, data show. And from 2005 to 2015,  rates of emergency department visits for heat-related illnesses increased by 67% for Black people in the United States, compared to 27% for white people, according to one research paper.

Hispanic communities in the United States are also disproportionately impacted by these climate-related ills. While nearly half of all people living in the United States live in counties with poor air quality, more than seven out of ten Hispanic people in the United States lived in counties that violated federal air pollution standards for one or more pollutants, research suggests. Hispanic children are twice as likely to die from asthma as non-Hispanic white children, Carver added.

“Exposure to pollutants is disproportionately experienced by Black and Hispanic populations, but emissions are disproportionately caused by white populations,” said Carver, noting a 2018 study that found the “pollution burden” was high among Black populations (56% inequity) and Hispanic populations (63% inequity), while white populations experienced a “pollution advantage” (17% equity), on average.

The fix isn’t easy; in fact, it’s multifaceted. “Interventions,” Carver said, “should provide both upstream and downstream solutions when addressing climate change and health equity.” She noted providing treatment, rehabilitation, and disaster recovery efforts as downstream efforts, and targeting structural causes, policies and systems as upstream approaches. “Upstream solutions have the greatest benefit, provide primary prevention, and promote climate-resilient communities,” Carver said.