While the theoretical and practical challenges in achieving No Net Loss of biodiversity are becoming increasingly well described and reported (see papers from Joe Bull, Martine Maron, and David Lindenmayer), the underlying concept of the mitigation hierarchy is both powerful and much more widely applicable than has so far been appreciated.
Currently there is a widespread and piecemeal project-level approach to achieving No Net Loss of biodiversity taking place. This means that, if biodiversity gains and losses were to be aggregated, biodiversity could be lost even if individual projects appear to be reaching their targets.
If the concept is to truly have biodiversity benefits, there is a need for a multi-scale approach to No Net Loss, so that wider goals are not contradicted by project-level use of the mitigation hierarchy.
In our publication we propose the use of the mitigation hierarchy to navigate the conservation-development trade-off at the broadest scale possible, the whole planet. Incorporating all human impacts on biodiversity within the single standardised paradigm with a broad biodiversity conservation goal. Crucially, a global mitigation hierarchy offers a systematic framework that is both scalable from the project to the national and international levels, as well as being standardised between the conservation sectors of sustainable use (e.g., certification schemes), minimising the impact of development (e.g., No Net Loss), and efforts to directly restore or protect sites (e.g., protected areas).
Conserving biodiversity while simultaneously seeking to use it for humanity’s needs is a huge challenge, which some suggest is not possible on our current growth trajectory. Others have called for half the planet to be set aside for biodiversity conservation, or for more space to be given to nature. But in the absence of a clear pathway to achieving it, it is difficult to see how these aspirations can translate into real biodiversity gains. Our approach cannot solve all of these challenges, but what the mitigation hierarchy offers is transparency, enabling clear understanding of what the consequences of various uses of nature are, with flexibility to address a variety of human impacts on biodiversity, across different sectors and scales.
Fundamental changes are needed if humanity is to reverse the current biodiversity crisis and put the planet on a sustainable course for the future. However, these changes will only be possible if we can see a way forward. Quantifying and accounting for all human-caused impacts to biodiversity could help humanity to reduce these impacts in a feasible and equitable way. A global mitigation hierarchy could be the first step towards achieving such a vision.