Abstract: Home to more than half of the total global population, urban regions are responsible for a significant amount of anthropogenic emissions of greenhouse gases and air pollutants (e.g., CO and NOx) into the atmosphere. Emissions from different cities and different parts of a city are highly heterogeneous considering differences in societal factors, regulations for land use, and technology. Space-based platforms offer a uniform perspective to observing and monitoring cities. In this presentation, we will cover what we have learned about inter- and intra- city variability in emissions from the sole use of column CO2 from OCO-2/3 along with the joint use of co-emitted tracers from TROPOMI. Specifically, we develop modeling tools for extracting urban emission signals from satellite column data, examine the relationship between emissions and societal factors, and explore the challenges and advantages of integrating multiple satellite products. By examining 20 cities around the globe, we find that denser cities tend to produce lower per capita CO2 emissions, albeit such anticorrelation is partially limited by the effect of per capita GDP. By zooming into individual city domains, we identify discrepancies in the combustion efficiency of industrial sectors in Los Angeles versus Shanghai. Ongoing work is constraining emission ratios between CO2 and air pollutants to determine sector-specific signals that can be relevant to emission regulation.