Of sets of offsets: Cumulative impacts and strategies for compensatory restoration

Abstract

a b s t r a c tBiodiversity offsets are increasingly advocated as a flexible approach to managing the ecological costs of economic development. Arguably, however, this remains an area where policy-making has run ahead of science. A growing number of studies identify limitations of offsets in achieving ecologically sustainable outcomes, pointing to ethical and implementation issues that may undermine their effectiveness. We develop a novel system dynamic modelling framework to analyze the no net loss objective of development and biodiversity offsets. The modelling framework considers a marine-based example, where resource abundance depends on a habitat that is affected by a sequence of development projects, and biodiversity offsets are understood as habitat restoration actions. The model is used to explore the implications of four alternative offset management strategies for a regulator, which differ in how net loss is measured, and whether and how the cumulative impacts of development are considered. Our results confirm that, when it comes to offsets as a conservation tool, the devil lies in the details. Approaches to determining the magnitude of offsets required, as well as their timing and allocation among multiple developers, can result in potentially complex and undesired sets of economic incentives, with direct impacts on the ability to meet the overall objective of ecologically sustainable development. The approach and insights are of direct interest to conservation policy design in a broad range of marine and coastal contexts.

Modeling Alternative Approaches to the Biodiversity Offsetting of Urban Expansion in the Grenoble Area (France): What Is the Role of Spatial Scales in ‘No Net Loss’ of Wetland Area and Function?

“…This is consistent with previous studies in Queensland, Australia [35] and Brazil's iron quadrangle [36]. Thébaud et al [37] also highlighted the constraint of available area of habitat in relation to offset success, in a case of marine development. Gordon et al [38] modeled how biodiversity offsets would perform in Melbourne, Australia.…”

Setting priorities for conservation at the interface between ocean circulation, connectivity, and population dynamics

“…Here, as in other studies (Sainsbury , Thébaud et al. , Britten et al. ), K i , t is interpreted as a proxy for the quality of the habitat supporting the coral community, which determines the maximum coral cover the zone can sustain.…”

Biodiversity Offset Program Design and Implementation

“…A number of authors have discussed the technical design of offsets with the aim to improve conservation outcomes and reach NNL or a net gain [18,30,31]. The effectiveness of offset programs is strongly dependent on the policy framework, offset design, the implementation thereof and compliance [12].…”

“…Effective offsets must counterbalance the impacts of a project, bring measurable long-term benefits, and produce desired results [11]. The effectiveness of offset programs strongly depends on the policy framework and implementation thereof [12][13][14]. Legislation provides a basic conceptualization as it sets a frame for implementation and applies existing paradigms, i.e., the polluter pays principle.…”