Environment:”True” conservation progress

The field of biodiversity conservation is hampered by weak performance measurement and reporting standards (1). In other areas, such as the corporate world, weak reporting of performance is considered bad practice, if not illegal (2, 3). Although various evaluation frameworks for conservation programs have been suggested (4–7), few simple measures for unbiased reporting have been developed (8). Credible performance measures should connect conservation outcomes to goals for public investment in conservation. Gains and losses must both be presented as an auditable conservation balance sheet (8), revealing the net benefit of conservation actions and policies reported against losses. A major conservation performance metric in government state of the environment reports (9–14) is the size of the physical area protected, or the change in area protected. For example, South Africa reported that 6% of terrestrial habitat was contained within protected areas in 1999 (9); in 2001, North America reported an increase in land within reserves over time (13). However, these numbers provide no information on loss of habitat outside (or inside) reserved areas, or conservation opportunity costs of securing areas for conservation (15). Even when habitat loss is reported (11, 12), it is rarely possible to evaluate net conservation outcomes