Land-use and climate risk assessment for Earth's remaining wilderness.

Earth's wilderness areas are reservoirs of genetic information and carbon storage systems, and are vital to reducing extinction risks. Retaining the conservation value of these areas is fundamental to achieving global biodiversity conservation goals; however, climate and land-use risk can undermine their ability to provide these functions. The extent to which wilderness areas are likely to be impacted by these drivers has not previously been quantified. Using climate and land-use change during baseline (1971-2005) and future (2016-2050) periods, we estimate that these stressors within wilderness areas will increase by ca. 60% and 39%, respectively, under a scenario of high emission and land-use change (SSP5-RCP8.5). Nearly half (49%) of all wilderness areas could experience substantial climate change by 2050 under this scenario, potentially limiting their capacity to shelter biodiversity. Notable climate (>5 km year-1) and land-use (>0.25 km year-1) changes are expected to occur more rapidly in the unprotected wilderness, including the edges of the Amazonian wilderness, Northern Russia, and Central Africa, which support unique assemblages of species and are critical for the preservation of biodiversity. However, an alternative scenario of sustainable development (SSP1-RCP2.6) would attenuate the projected climate velocity and land-use instability by 54% and 6%, respectively. Mitigating greenhouse gas emissions and preserving the remaining intact natural ecosystems can help fortify these bastions of biodiversity.

Conservation prioritization can resolve the flagship species conundrum.

Conservation strategies based on charismatic flagship species, such as tigers, lions, and elephants, successfully attract funding from individuals and corporate donors. However, critics of this species-focused approach argue it wastes resources and often does not benefit broader biodiversity. If true, then the best way of raising conservation funds excludes the best way of spending it. Here we show that this conundrum can be resolved, and that the flagship species approach does not impede cost-effective conservation. Through a tailored prioritization approach, we identify places containing flagship species while also maximizing global biodiversity representation (based on 19,616 terrestrial and freshwater species). We then compare these results to scenarios that only maximized biodiversity representation, and demonstrate that our flagship-based approach achieves 79-89% of our objective. This provides strong evidence that prudently selected flagships can both raise funds for conservation and help target where these resources are best spent to conserve biodiversity.

Influence of adaptive capacity on the outcome of climate change vulnerability assessment.

Climate change vulnerability assessment (CCVA) has become a mainstay conservation decision support tool. CCVAs are recommended to incorporate three elements of vulnerability - exposure, sensitivity and adaptive capacity - yet, lack of data frequently leads to the latter being excluded. Further, weighted or unweighted scoring schemes, based on expert opinion, may be applied. Comparisons of these approaches are rare. In a CCVA for 17 Australian lizard species, we show that membership within three vulnerability categories (low, medium and high) generally remained similar regardless of the framework or scoring scheme. There was one exception however, where, under the warm/dry scenario for 2070, including adaptive capacity lead to five fewer species being classified as highly vulnerable. Two species, Eulamprus leuraensis and E. kosciuskoi, were consistently ranked the most vulnerable, primarily due to projected losses in climatically suitable habitat, narrow thermal tolerance and specialist habitat requirements. Our findings provide relevant information for prioritizing target species for conservation and choosing appropriate conservation actions. We conclude that for the species included in this study, the framework and scoring scheme used had little impact on the identification of the most vulnerable species. We caution, however, that this outcome may not apply to other taxa or regions.