Biodiversity offsetting is a tool that could be used to compliment other methods to avoid, remedy and mitigate effects. The international Business and Biodiversity Offsets Programme (BBOP) defines biodiversity offsetting as:
"measurable conservation outcomes of actions designed to compensate for significant residual adverse biodiversity impacts arising from project development after appropriate prevention and mitigation measures have been taken. The goal of biodiversity offsets is to achieve no net loss and preferably a net gain of biodiversity on the ground with respect to species composition, habitat structure, ecosystem function and people’s use and cultural values associated with biodiversity".
The definition is based on biodiversity offsets being considered last. That is, developers should first seek to avoid, then minimise (design a project to reduce harm) and then remedy (e.g. make good temporary impacts at the site) their impacts on biodiversity. Offsetting is then used to address remaining, or residual, unavoidable impacts on biodiversity. There are ten key principles that must be adhered to for a biodiversity offset to meet international best practice. See the BBOP site for further information about these principles, and about the international standard that BBOP have developed.
New Zealand-specific guidance on voluntary biodiversity offsetting is expected to be available later in 2013.