The second cloud over tropical certification schemes, as Wal-Mart may find, is doubt about their reliability.

ECONOMIST: Western consciences can do only so much to conserve forests

Mr Kingsley added that his company was "likely" to sign up to Microsoft's certification schemes.

BBC: Minecraft screenshot

In messy countries like Cameroon, certification schemes get corrupted.

ECONOMIST: Western consciences can do only so much to conserve forests

The book also highlights new initiatives and alliances such as the, the Green Development Initiative which aims to establish an area-based certified biodiversity unit, the ISEAL Alliance which is exploring the biodiversity dimensions of environmental and social certification schemes, the Malua BioBank in Malaysia, and Mission Markets which has established an e-platform for biodiversity deals.

FORBES: Making the economic case for business and biodiversity