A calculated approach

Australia is one of the most biodiverse countries in the world, but as urban and industrial demands push development further into natural environments, our biodiversity has undergone the largest documented decline of any continent over the last 200 years.

Environmental offsetting, which involves restoring biodiversity at one site to compensate for losses at another, has been used by developers with varying effectiveness for decades. Done well, it offers a win-win solution – but achieving that perfect balance is a controversial issue that involves complicated questions.

Determining what and how much can be replaced, and estimating how long it will take to restore what’s been lost, can be difficult to establish, and in the past, decision-makers often did not have the tools needed to address these issues. So, historically, environmental offsetting has been largely inconsistent and therefore mostly ineffective.

In late 2012, Professor Martine Maron, Dr Megan Evans and Professor Hugh Possingham from UQ’s Centre for Biodiversity and Conservation Science, set out to find a solution by developing a calculation approach that determines effective environmental offsets for impacted habitats. 

Their approach has resulted in an approach now being used by major governments, regulatory bodies and development corporations in Australia and around the world.

Calculating the solution

Professor Maron, Professor Possingham and Dr Evans set about creating a more consistent, easily understood approach to offsetting to improve the process in future. The project’s initial funding came from the National Environmental Research Program (NERP), when the Department of Environment approached the team about creating a scientific approach to calculating environmental offsets.

Drawing from their past work on offsets, the team developed a step-by-step approach to identifying the required gain to counterbalance a biodiversity loss, and the likely outcomes from an offset. It combined novel elements with well-established principles on estimating benefit from conservation actions.

This was translated into the Australian Government’s Offset Assessment Guide – a decision-support tool that calculates what conservation actions are required to offset a development’s impact on threatened species. The guide deals with species that have vastly different ecological requirements, and applies the concept of ‘time discounting’ – penalising offsets that take too long to yield benefits, thus disincentivising long delays that threaten near-extinct species.

“Our tool integrates the unique requirements of different species and ecological communities with a transparent treatment of risk, time delays, and alternative future scenarios, all of which are inherent factors of offsetting,” Professor Possingham says.

The guide offers rapid, transparent, robust and flexible decision support to developers, which benefits them by ensuring the significant time and resources they invest in offsets are spent effectively and are of benefit to the environment.

“There has been good acceptance of the logic of the approach, and I think that the really close collaboration that we had with our federal government colleagues over the course of the guide’s development has produced an enduring outcome,” says Dr Evans.