The relationship between climate change and cities is complex. City-based activities contribute significant amounts of greenhouse gases and, simultaneously, are often more vulnerable to the impacts of climate change. Dhaka is now the world's eighth largest city and a significant proportion of Bangladesh's greenhouse gases are generated there although, relative to total emissions worldwide, the contribution is negligible. But this contribution is likely to increase rapidly with the continuing growth of the city's population, economy and electricity consumption, as well as increased motor vehicle use. At the same time, Dhaka is prone to damaging and costly flooding, both from the rivers that bound it and from rainfall that generates runoff that is beyond the capacity of the drains. In less than 20 years, the city has faced three major floods, each causing huge damage and economic loss. Although the government has taken a number of measures to improve both Dhaka's air quality and its capacity to withstand floods, there are further opportunities in both areas. This paper discusses, in specific terms, the scale of the threats, the measures taken to address them and the potential for more effective action.