However, rapidly growing urban areas in parts of South Asia and the Middle East continue to show increasing dependence on fossil fuels. This suggests that economic expansion in these regions remains closely tied to combustion-based energy systems.

For example, 390 cities matched trends of economic growth, but with increased use of fossil fuels – including Moscow, Tashkent, Izmir, Riyadh and Abu Dhabi.

The study notes key uncertainties, including uneven economic data quality between countries, a study boundary that does not consider how cities’ total emissions footprints may be growing due to imports from global supply chains, and the relatively short six-year timeframe, which also covers the disruptions of the COVID-19 pandemic.

The authors also note that changes in the air pollutant nitrogen dioxide do not necessarily reflect a change in carbon dioxide or other greenhouse gases.

Despite these constraints, it offers a scalable, satellite-based framework that can be updated regularly, providing a powerful new tool for tracking urban sustainability transitions and informing policy.

The value of Sentinel-5P is clearly highlighted in the study as a powerful tool for monitoring real-world environmental change. By providing objective, global-scale measurements of air pollution, the satellite is helping researchers and policymakers track the effectiveness of green policies and identify pathways to cleaner economic growth.

The recently-launched Sentinel-4 and Sentinel-5 missions are taking air quality and atmospheric composition monitoring into the future.

From geostationary orbit, Sentinel-4 delivers data every hour, providing information on a wide range of trace gases and pollutants to forecast and monitor air quality over Europe, while Sentinel-5 in polar orbit (like Sentinel-5P) provides global data to support science, forecasts and public health alerts for air pollution, UV radiation, greenhouse gases and climate research.