Australia (Victoria)

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Attention is now turned to comparisons with other metrics beginning with Australia, among the earliest pioneer countries to adopt a biodiversity offsetting scheme 1. The different states within Australia each adopt their own metrics, hence, it is no surprise that both states  utilise metrics with different calculation methods. In this section, the core components and attributes of the state’s metric are compared separately alongside the SGBA followed by comparable habitat condition criteria. 

The Australian state of Victoria was the first Australian state to adopt a biodiversity offsetting scheme in Australia 1. Victoria’s offsetting policy is based on a “No Net Loss” policy and is largely centred around the projection of biodiversity decline. Biodiversity decline is defined as biodiversity loss (measured via proxy unit[s]) over time. The rate of decline is a projection based on the assumption that no offsetting measure is taken. The projected decline in biodiversity over time in the face of developmental impact is termed the debiting baseline, in the absence of any biodiversity offset measures. In the presence of biodiversity offset measures, the rate of biodiversity decline due to developmental impact is termed the crediting baseline. If the rate of decline (i.e., biodiversity loss over time) is overestimated, this subsequently overestimates the projected averted loss (i.e., gains attributed to conservation measures), thereby making No Net Loss easier to achieve via the overstating of projected gains. The improvement in biodiversity value (over time) is also a projection based on the assumption that offsetting measures are taken.

The Victoria offsetting policy has been reportedly flawed in its methodology: gains resulting from projected averted loss were overestimated due to two components taken into calculations. One is the "prior management gain" which refers to pre-existing management by landowners before offsetting takes place, and, therefore, ought not to be considered as part of any actual offsetting attempts. The second is the "security gain" which refers to administrative protection of land for conservation which might artificially (as shown in a post-hoc retrospective re-estimations using local authority and satellite data) double yet another component in calculations termed the "maintenance gain" (i.e., retention of existing vegetation condition). The proposed removal of both "prior management" and "security" gains would increase development costs and entail political tensions due to pricier biodiversity credit purchases. Overestimation of averted loss gains of  up to five times the actual rates of decline are not confined to Victoria state's offset policy but reportedly all other Australian state and territorial offset policies 1. 

The trading methodology governing the Vegetation Quality Assessment (VQA)  is termed “like-for-like” or “in-kind” offsetting which refers to a trading scheme in which one biota may be used to compensate for the loss of another according to shared key characteristics 1. There are two categories of offsets, namely, "General" and "Species" offsets with a “like-for-like” or “in-kind” rule. In common to both categories is the requirement for a one-to-one compensation for large trees. For a General offset, requirements include a set minimum Strategic Biodiversity Value (SBV; partially similar to the SGBA's notion of "habitat distinctiveness") and same local authority-designated location as the development site. A Species offset requires compensation in terms of the same habitat occupied by the same threatened species impacted. However, there are certain exceptional conditions where the "like-for-like" rule need not apply: a rare or threatened species habitat may be removed if it does not possess characteristics supportive of the species in question 2. In a similar vein, an offset site of a different (vegetation type) habitat that supports that of the rare or threatened species of a habitat to be removed may be considered sufficient for offsetting if it possesses characteristics supportive of the species in question. What follows is an overall comparison of the VQA metric with the SGBA (see table below).

1: O'Brien & Gordon (2024)

2: Department of Environment, Land, Water and Planning (DELWP, 2017))