This research looks at how big cities and the world economy affect each other in the context of climate change policies. The scientists used a complex model to study how making urban areas more efficient and adding a cost to carbon emissions can impact the global economy. They found that when cities improve their infrastructure and have a price on carbon emissions, it's possible to reduce pollution significantly without hurting the economy too much. By combining these two strategies, we can aim for strict pollution reduction goals while still keeping economic costs manageable.