A major study analyzing 2,475 of the world’s largest cities finds that in about 80% of them, economic growth accompanies a reduction in fossil-fuel–related NO2 emissions, signaling a decoupling of growth from fossil fuels.

Greenness is defined broadly in the study, with roughly 80% of the cities showing both rising GDP per capita and falling NO2, suggesting that strong green policies can sustain prosperity without increased fossil-fuel dependence.

NO2 levels were measured in the troposphere over cities from 2019 through 2024, and about 2,000 cities exhibited GDP per capita growth while NO2 emissions declined, labeled as “green” cities.

Independent experts, including prominent voices like Michail Fragkias, stress the crucial role of urban leadership in tackling 21st‑century sustainability challenges.

The study highlights cities’ pivotal role in sustainability and notes regional differences in the pace of decoupling emissions from growth.

Out of 5,435 cities considered, 2,919 showed no significant NO2 change and 41 had unreliable GDP data, leaving 2,475 cities in the core analysis.

Researchers combined Copernicus Sentinel-5P satellite NO2 data with per-capita GDP data from 2019–2024 to evaluate the emissions–economic activity relationship in cities.