Sir

Your Editorial 'Markets can save forests' (Nature 452, 127–128; doi:10.1038/452127b 2008) proposes integrating deforestation into the international carbon market, but it is unlikely that money alone can solve the problem.

The process of tropical deforestation presents a dilemma: enormous economic value (more than US$2,000 a year per hectare) is lost in favour of small private benefits (often less than US$100 a year per hectare). In a true market, an increased, scarcity-signalling price should provide an incentive to boost the supply of the scarce commodity. So far, this has not worked in the case of tropical forests. Real financial flows received for the provision of ecosystem services are vanishingly small, if they exist at all — only a few beneficiaries have been convinced to pay for environmental services. This illustrates the essentially theoretical character (at least, up till now) of economic values generated by ecosystem services.

'Payments for ecosystem services' are supposed to save tropical forests. But even if it were possible to mobilize substantial payments, tropical farmers wouldn't be prepared to stand by and twiddle their thumbs while receiving them. They need a field of activity, so sustainable land-use concepts should address the social environment and needs of people as well. These concepts could be linked and possibly financed by such payments.

If the people who use tropical lands are disregarded, we don't believe that payments for ecosystem services will solve the problem of disappearing tropical forests. What is needed is an economic system that keeps people gainfully employed in an activity that is ultimately productive, not destructive.