Rapid urbanisation will have huge economic, social and environmental implications. This paper summarise the urbanisation dynamics of sub-Saharan Africa's largest cities using new data on population,GDP and carbon emissions up to 2030, to provide an understanding of the scale and pace of change in sub-Saharan Africa's cities and their contribution to the economy and climate. The paper then outlines a range of "what if" scenarios to assess the potential for reducing carbon emissions through transformative shifts away from "business as usual" investments in the transport sector. Then identify five major groups of cities (or urban types) based on population and levels of income, and examine the dynamics of these different groups in terms of population size, GDP per capital and carbon emissions.