Australian scientists have warned governments against using biodiversity offsetting to meet existing conservation commitments.
The University of Queensland's Associate Professor Martine Maron said research had shown that interest in offsetting - creating a similar environment or habitat in a different location to replace ones damaged through development - had surged over the past decade.
"Planning authorities and developers use biodiversity offsets to compensate for damage to species and habitats caused by human activities, by generating a biodiversity benefit elsewhere," she said.
"As the approach has gained popularity, governments have increasingly been recognising that industry money generated by offsets could help them achieve national conservation goal targets to which they had already committed - such as those under the Convention on Biological Diversity."
Dr Maron, an Australian Research Council Future Fellow at the UQ School of Geography, Planning and Environmental Management, said in most cases governments were simply failing to think through the implications of using offsets in this way.
"For an offset to be valid, it has to create biodiversity benefits beyond those that would occur anyway.
"So offsets can fund protected areas - but using them to achieve a government's pre-existing commitments is an admission that those commitments were not otherwise going to be met.
"That might be a reasonable admission for developing nations, but is unlikely to be acceptable from wealthy nations.
"We recommend that future international conservation agreements explicitly require separate accounting of protected areas created as offsets."
UQ and Wildlife Conservation Society researcher and Society for Conservation Biology President Associate Professor James Watson said offsetting, if done appropriately, was likely to be a very important way of reducing net harm to biodiversity from development.
"But we are not always aware of the risks of using this relatively new tool," he said.
Dr Watson said the research was relevant to all governments with protected area targets under the Convention on Biological Diversity - relating to both management of protected areas and increasing the extent of the protected area estate.
"We argue that buying or managing protected areas using funds from offsets cannot count towards meeting their previously-agreed targets without making the offset invalid," he said.
Dr Watson said governments, business and environmental non-government organisations involved in offset policy development and implementation were also affected.
"We conclude that, with care, biodiversity offsets can help reconcile development with conservation - but if they allow governments to renege on their existing commitments by stealth, biodiversity offsets could cause more harm than good," he said.
The research is published today in Nature, in a paper by Dr Maron, Dr Watson and Professor Hugh Possingham (UQ); Dr Ascelin Gordon (RMIT) and Professor Brendan Mackey (Griffith University).