Nature-based climate solutions require a mix of socioeconomic and governance attributes.

Nature-based climate solutions (NCS) can play a crucial role in reducing climate change. There is, however, a lack of understanding of the biophysical, social, and political contexts surrounding NCS, which hampers its practical implementation. Here, we used estimates of carbon sink potential to identify socioeconomic and ecological factors that may stimulate NCS implementation in developing economies. We considered carbon sink potential for eight NCS, including reforestation, peatland restoration, natural forest management, improved rice cultivation, optimal grazing intensity, grazing (legumes), avoided peatland impacts, and avoided coastal impacts. Food insecurity hotspots, which currently receive the most development aid, have the lowest likelihood of realizing NCS' potential. Poor governance structures and food insecurity impede the implementation of NCS projects at the country level. By carefully assessing complementary food security, sustainable financing, and soil quality safeguards, NCS as a nationally determined contribution to climate mitigation can be made more effective.

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.