This paper compares the opportunities or economically attractive low-carbon investment opportunities in five cities: Leeds in the UK, Kolkata in India, Lima in Peru, Johor Bahru in Malaysia and Palembang in Indonesia. This paper compares the results of these studies and argues that there is a compelling economic case for cities in both developed and developing country contexts to invest, at scale, in cost-effective forms of low-carbon development. The paper highlights that large-scale low-carbon investments can appeal to local decision-makers and investors on direct, short-term economic grounds. They also indicate that climate mitigation ought to feature prominently in economic development strategies as well as in the environment and sustainability strategies that are often more peripheral to, and less influential in, city-scale decision-making.