Huge profits made by London-based brokers who arrange emissions-cutting projects in developing countries contrast with little benefit for the world's poorest nations, company and United Nations data shows.

The Kyoto Protocol on global warming allows rich countries to meet greenhouse gas emissions targets by paying poor nations to cut emissions on their behalf, using the so-called clean development mechanism (CDM).

Roughly four billion people, mostly in developing countries, subsist at the bottom of the economic and social pyramid. They are vulnerable not only to the risks associated with poverty, unemployment and social exclusion, but also to a host of environmental threats including poor air quality, contaminated water and climate change. Linking their entrepreneurial talent with the need to overcome the environmental conditions in which they live could accelerate the deployment of environmental technologies, help overcome urban poverty, and create more sustainable cities.