The debate over whether national protected areas are eligible for biodiversity-offset funding should factor in the different challenges and contexts for countries seeking to conserve their biodiversity (see M. Maron et al. Nature 523, 401–403; 2015).
Offsets that are voluntary (such as those of the mining companies Minera Panamá and QIT Madagascar Minerals; see also go.nature.com/zxv1et) are a source of extra conservation funding. This is analogous to grants from foundations or from the Global Environment Facility, which are considered a legitimate way to finance fulfilment of the Aichi biodiversity targets (see go.nature.com/avssmr).
In countries where offsets or compensation payments are required by law or lender standards, they serve as a tax on environmental impacts. This follows the accepted 'polluter pays' taxation model, and has the benefit of earmarking the revenue for conservation.
In heavily populated regions, the only socially acceptable place to implement offsets might be in protected areas selected by public processes. In such settings, offsets and protected areas would need to be closely linked.
Excluding offsets or compensation from financing of protected areas would affect developing countries, most of which struggle to finance such areas. It would, for example, exclude all of Brazil's protected-areas system from contributing to Aichi Target 11, because compensation is integral to the country's law on protected areas.