Proceeding with caution

What is more important for sustainability is how to manage risks by retaining options. There is considerable uncertainty about the consequences of human actions on complex ecosystems: small changes can sometimes accumulate and translate into losses of whole ecosystems (see box 2.5) There is also uncertainty about what technological innovations will be available and when. Where the costs of human actions today are uncertain, with potential for large and irreversible damage, there is a need for proceeding with greater caution in maintaining environmental and social assets.