'Green' labelling of items produced sustainably has become a much-publicized tool of the environmental movement. But green-label criteria that were developed for forestry are now being inappropriately applied to agricultural crops — with unacceptable risks to wildlife.

The high conservation value (HCV) concept was originally intended for timber harvested without harming large forest blocks or critically endangered flora and fauna. It has since been extended to some of the most rapidly expanding crops in the tropics — namely, oil palm, soya bean, sugar cane and cacao — ostensibly to ensure their 'sustainable' production.

The combined area of these four crops increased by 36.5 million hectares between 1999 and 2008, largely in countries of exceptional biodiversity, such as Brazil and Indonesia, and largely at the expense of forest. The hope is that green labelling through HCV will stem this tide of habitat destruction and biodiversity loss.

But many of the world's most intact and biodiverse tropical forests (including the Amazon Basin, Congo and New Guinea) harbour few critically endangered species. In such cases, the only HCV criterion that is likely to prevent forest conversion to agriculture is the one protecting large expanses of habitat.

Unfortunately, the round tables for oil palm, soya bean, sugar cane and cacao have decided that only forest blocks larger than 20,000–500,000 hectares (depending on the country) are eligible for protection under this criterion. So crops replacing areas of forest below these thresholds can perversely carry a green label, even though these thresholds are dangerously high for wildlife survival.

The size of HCV thresholds must be drastically reduced so that green-labelled crops are not simply 'greenwash'.