Sir

The world's religions are emerging as a surprising driver of support for conservation of biological diversity.

The International Interfaith Investment Group, for example, which is collectively worth more than US$7 trillion, is encouraging religious organizations to change their current investment policies in favour of those that support conservation (http://www.3ignet.org).

In addition, lands owned by these organizations can contribute to the conservation of biodiversity because of their protected status. More than 7% of Earth's land surface is owned by religious institutions, and a further 8% has sacred links (http://www.arcworld.org). Given that most countries will never be able to designate more than 15% of their land as protected areas (S. Chape et al. Phil. Trans. R. Soc. B 360, 443–455; 2005), territory with religious and sacred affiliations contributes substantially to maintaining biodiversity.

It should also be possible to raise funding for conservation by appealing to donors who have religious faith. For example, the wealthy countries of the G20 group that have large religious populations might step in and help.

The focus of initiatives in the past has been on paying for ecosystem services, which are considered 'natural capital' (R. Costanza et al. Nature 387, 253–260; 1997), but an appeal to support native communities on religious grounds might prove more persuasive in a difficult economic climate.

Of the 125 countries that are represented in the Conservation International list of biodiversity hotspots (http://www.biodiversityhotspots.org), most have a low per-capita gross domestic product (GDP) and a strong religious base (http://tinyurl.com/2b2kg9). Collectively, these countries are home to more than 4 billion people affiliated with one of 11 mainstream faiths; more than half of them have a total population of 3 billion and a per-capita GDP of less than US$5,000.

Religious sympathy has the potential to make a major contribution towards biodiversity conservation. This contribution could be extremely valuable in the approach to the 2010 target of the Convention on Biological Diversity.