Kind of seems dumb to compare an entire industry to equivalent number of cars.
Why? Its more equivalent emissions than several states total vehicle emissions. CO2e is a consistent measure when looking at greenhouse gas emissions and cars are something people are familiar with.
From the articles page:
Results A total of 1.6 billion inhalers were dispensed in the US from 2014 to 2024, generating an estimated 24.9 million metric tons of CO2e (mtCO2e). Annual emissions increased by 24% from 1.9 million mtCO2e in 2014 to 2.3 million mtCO2e in 2024. Metered-dose inhalers were responsible for 98% of all emissions during the study period, and emissions were heavily concentrated among short-acting β-agonist, inhaled corticosteroid–long-acting β-agonist, and inhaled corticosteroid classes. Albuterol, budesonide-formoterol, and fluticasone propionate inhalers accounted for 87% of total emissions. The estimated social costs of emissions were $5.7 billion (lower bound, $3.5 billion; upper bound, $10.0 billion).
Its an enormous amount of emissions.