Seeing no net loss: Making nature offset-able.

Policies for biodiversity no net loss and net gain underwrite narratives for green growth through advancing reparative logics to ongoing habitat impacts. By enabling offsetting practices that risk accommodating rather than averting land change developments, net principles are said to resemble modes of 'accumulation by environmental restoration'. Biodiversity net principles are frequently depicted visually as a diagram of the mitigation hierarchy for communicational ease and have proliferated over recent decades despite little evidence for their ecological effectiveness. This paper combines economic sociology, visual media analysis of the net diagram and political ecology to account for the stabilisation of net principles in policy frameworks. It highlights the upstream imaginative work that this visual tool and its wider assemblages perform to support offsetting and habitat banking practices on the ground. The paper positions the NNL diagram as a conceptual and ideational technology. It traces the practices through which biodiversity is rationalised by the Cartesian coordinates of an XY schematic, and en-framed as a measure of numerical value on a vertical scale. The effect is to engender coherence to the idea of netting out differences in aggregate sums of biodiversity unit value, making nature conceptually offset-able. I develop this account through a history of the diagram as well as the broader processes that have shaped the policy and its arrival in English planning frameworks. Observers increasingly question how biodiversity offsetting and no net loss/ net gain have become so popular when their empirical foundations are so weak. This paper proposes that within the wider assemblages of actors, one answer is located in the potency and mobility of conceptual technologies such as diagrams of no net loss or net gain of biodiversity and the logic of balance-sheet accounting that is imbricated within the visual design. [ABSTRACT FROM AUTHOR]