“Inhalers produce as much carbon emissions as half a million cars each year.” That’s how headlines read after a startling new JAMA analysis revealed that the 160 million inhalers dispensed in the US each year release as much greenhouse gases as 530,000 gas-powered vehicles. Metered-dose inhalers (MDIs) were by far the worst offenders. A single MDI releases about as many hydrofluorocarbon propellants in a year as driving a car for 100 miles, the study found.

For the public, the study highlighted the asthma and chronic obstructive pulmonary disease (COPD) medicines as a significant driver of global warming — but for physicians, it offered a clear call to action.

“Imagine if you could get rid of the emissions of hundreds of thousands of cars on the road with a fairly simple solution,” said study author William Feldman, MD, PhD, MPH, a pulmonologist and health services researcher at the University of California, Los Angeles. “If you do a small thing, you have this huge scale that can magnify this change. Not a lot of environmental impact initiatives have that scale opportunity.”

The healthcare sector is responsible for an estimated 8.5% of US greenhouse gas emissions — adding to air pollution that exacerbates “the very respiratory conditions inhalers are meant to relieve,” wrote Alexander S. Rabin, MD, and colleagues in an accompanying editorial.

The field’s environmental successes are scarce. Some operating rooms have removed highly polluting anesthetic gases, gastroenterologists are transitioning away from disposable scopes, and hospitals are increasingly exploring ways to use renewable energy.

Inhaler prescribing presents a unique opportunity for physicians to impact climate change in everyday decisions. However, switching patients to more environmentally friendly options isn’t likely to be straightforward — here’s what doctors need to know. 

How to Consider Switching

The most prescribed inhalers pose the greatest opportunity to make an impact. In the study, albuterol, budesonide-formoterol, and fluticasone propionate inhalers combined accounted for 87% of total emissions.

“One practical place to start may be switching to the lower emissions intensity albuterol,” said pulmonologist and critical care physician Nicholas Nassikas, MD, an assistant professor of medicine at Harvard Medical School, and a core faculty member at the Harvard T.H. Chan School of Public Health’s Center for Climate, Health, and the Global Environment, Boston. Nassikas was not involved in the study.

Lower-emissions inhalers include soft mist or dry powder options, which don’t use propellants and therefore don’t emit as much greenhouse gas as propellant-based devices. 

In the US, access to these options varies. For COPD, long-acting muscarinic antagonists (LAMAs) and long-acting beta-agonist-LAMA combinations are widely available in dry powder and soft mist formulations, according to the editorial. Dry powder albuterol is approved in the US, but because no generic option is available, it tends to be more expensive.

Insurance coverage changes could be an opening for the conversation, Nassikas said. “[Use] a formulary change as an opportunity to consider a dry powder inhaler over a metered-dose inhaler if indicated.”

Talking to Patients

Propellants harm patients by contributing to climate change, and that means physicians are obligated to consider inhaler switching under the Hippocratic oath, said Eric Balaban, MD, a pulmonary and critical care fellow at Temple University Lewis Katz School of Medicine in Philadelphia. (Balaban was not involved in the study.)

“I think people would be surprised to find that most patients would be amenable to at least trying a different inhaler,” Balaban said. Less than 10% of the population are “hardened climate refusers,” he said. “That means that 90-plus percent of patients are either very concerned or are at least climate sympathetic, meaning they don't want to pollute.” 

Try this approach: Say, “This inhaler that you’re taking is helping your symptoms, but there’s a different inhaler that should do something very similar but will offer less pollution,” Balaban suggested. You could mention the new study’s findings and point out that a small change can be part of a bigger, long-term solution for easing asthma and COPD symptoms. Consider: During the lockdown phase of the COVID pandemic, when air pollution measurably improved, researchers noted fewer exacerbations and hospital visits among patients with asthma and COPD.

Any substitutions need to be “grounded in clinical evidence, responsive to patient needs, and implemented with care,” the editorial writers wrote. Rabin’s paper earlier this year in JAMA Internal Medicine showed veterans who switched from budesonide-formoterol metered-dose therapy to fluticasone-salmeterol dry powder therapy experienced higher rates of emergency department visits and hospitalization. The outcomes “likely reflect pharmacological differences between the component medications (eg, fluticasone vs budesonide), challenges with dry powder drug delivery among older veterans with COPD, and gaps in clinician communication and inhaler education during the transition.”

Before switching, it’s a good idea to educate patients on inhalation techniques and evaluate whether their technique is effective, Feldman said.

Options May Change

While availability and cost remain significant barriers to environmentally friendly inhalers, the landscape is quickly evolving — with cleaner propellants on the horizon.

Some of these next-gen propellants are already poised for FDA approval, Feldman said. Right now, it looks like Breztri may be the first to market. In a news release last year, AstraZeneca said its novel propellant has “99.9% lower global warming potential than propellants used in currently available inhaled medicines.” Others in the pipeline include a low-carbon version of GSK’s Ventolin inhaler and DevPro Biopharma’s DevPro DP007 albuterol MDI.

“We need these inhalers with novel propellants because there are some patients — especially younger kids and older adults with poor respiratory force — who really require metered-dose inhalers,” Feldman said.

Meanwhile, physicians’ efforts to effect change may need to start with advocacy, Nassikas said. “Formulary changes may be a reasonable place to start, rather than asking providers or patients to make these changes.”

Other countries with more soft mist and dry powder options have already charted a course, Feldman said. In the US, MDIs account for 70% dispensed, but just 25% in Sweden, 36% in Japan, 40% in Denmark, and 53% in China.

“My fundamental message is if we really want to see change, we need to see structural change,” he said. “We need to see political and regulatory change to make it easier to prescribe inhalers that are better for the environment.”

Balaban said that looking for switching opportunities and advocacy should happen in tandem.

Climate change is a major health issue, he said. The State of Global Air report estimated that air pollution accounts for more than 8 million deaths a year. In the US, 46% of Americans or 156 million people, live in areas with failing grades for unhealthy levels of ozone or particulate pollution, according to the American Lung Association’s 2025 State of the Air report.

“If we accept that climate change is poisoning the air and that our medicines are contributing to that, then there’s simply an immutable call to action,” Balaban said.