Sir

Douglas J. McCauley, in his Commentary “Selling out on nature” (Nature 443, 27–28; 2006), suggests that love for nature is incompatible with valuing nature in terms of its contributions to human well-being. But there is no such conflict. Nor is valuation of ecosystem services a panacea; rather, such valuation is one piece of helpful information in the complex task of sustainably managing our natural assets.

Valuing ecosystem services is not identical to commodifying them for trade in private markets. Most ecosystem services are public goods (non-rival and non-excludable), which means that privatization and conventional markets work poorly, if at all. Nevertheless, knowing the value of ecosystem services is helpful for their effective management, which in some cases can include economic incentives, such as those used in Costa Rica's highly successful system of payment for these services (see http://www.conservation.org/xp/frontlines/partners/03150604.xml).

It is incorrect to suggest that ecosystem-services reasoning ignores basic ecology; on the contrary, it embraces ecology and the co-dependency of humans and other species. It is also incorrect to suggest that conservation based on protecting ecosystem services is betting against human ingenuity. The study of ecosystem services has merely identified the limitations and costs of 'hard' engineering solutions to problems that in many cases can be more efficiently solved by natural systems. Pointing out that the 'horizontal levees' of coastal marshes are more cost-effective protectors against hurricanes than constructed vertical levees is only using our intelligence and ingenuity, not betting against it.

The ecosystems-services concept makes it abundantly clear that the choice of “the environment versus the economy” is a false choice. If nature contributes significantly to human well-being, then it is a major contributor to the real economy (R. Costanza et al. Nature 387, 253–260; 1997), and the choice becomes how to manage all our assets, including our natural and human-made capital, more effectively and sustainably (R. Costanza et al. BioScience 50, 149–155; 2000).

I do not agree that more progress will be made by appealing to people's hearts rather than their wallets. Ecosystems are critical to our survival and well-being for many reasons — hearts, minds and wallets included.