Ongoing declines for the world's amphibians in the face of emerging threats.

Systematic assessments of species extinction risk at regular intervals are necessary for informing conservation action1,2. Ongoing developments in taxonomy, threatening processes and research further underscore the need for reassessment3,4. Here we report the findings of the second Global Amphibian Assessment, evaluating 8,011 species for the International Union for Conservation of Nature Red List of Threatened Species. We find that amphibians are the most threatened vertebrate class (40.7% of species are globally threatened). The updated Red List Index shows that the status of amphibians is deteriorating globally, particularly for salamanders and in the Neotropics. Disease and habitat loss drove 91% of status deteriorations between 1980 and 2004. Ongoing and projected climate change effects are now of increasing concern, driving 39% of status deteriorations since 2004, followed by habitat loss (37%). Although signs of species recoveries incentivize immediate conservation action, scaled-up investment is urgently needed to reverse the current trends.

The carbon costs of global wood harvests.

After agriculture, wood harvest is the human activity that has most reduced the storage of carbon in vegetation and soils1,2. Although felled wood releases carbon to the atmosphere in various steps, the fact that growing trees absorb carbon has led to different carbon-accounting approaches for wood use, producing widely varying estimates of carbon costs. Many approaches give the impression of low, zero or even negative greenhouse gas emissions from wood harvests because, in different ways, they offset carbon losses from new harvests with carbon sequestration from growth of broad forest areas3,4. Attributing this sequestration to new harvests is inappropriate because this other forest growth would occur regardless of new harvests and typically results from agricultural abandonment, recovery from previous harvests and climate change itself. Nevertheless some papers count gross emissions annually, which assigns no value to the capacity of newly harvested forests to regrow and approach the carbon stocks of unharvested forests. Here we present results of a new model that uses time discounting to estimate the present and future carbon costs of global wood harvests under different scenarios. We find that forest harvests between 2010 and 2050 will probably have annualized carbon costs of 3.5-4.2 Gt CO2e yr-1, which approach common estimates of annual emissions from land-use change due to agricultural expansion. Our study suggests an underappreciated option to address climate change by reducing these costs.

Costs in conservation: Common costly mistakes and how to avoid them.

There has been an increasingly prevalent message that data regarding costs must be included in conservation planning activities to make cost-efficient decisions. Despite the growing acceptance that socioeconomic context is critical to conservation success, the approaches to embedded economic and financial considerations into planning have not significantly evolved. Inappropriate cost data is frequently included in decisions, with the potential of compromising biodiversity and social outcomes. For each conservation planning step, this essay details common mistakes made when considering costs, proposing solutions to enable conservation managers to know when and how to include costs. Appropriate use of high-quality cost data obtained at the right scale will improve decision-making and ultimately avoid costly mistakes.

Area-based conservation in the twenty-first century.

Humanity will soon define a new era for nature-one that seeks to transform decades of underwhelming responses to the global biodiversity crisis. Area-based conservation efforts, which include both protected areas and other effective area-based conservation measures, are likely to extend and diversify. However, persistent shortfalls in ecological representation and management effectiveness diminish the potential role of area-based conservation in stemming biodiversity loss. Here we show how the expansion of protected areas by national governments since 2010 has had limited success in increasing the coverage across different elements of biodiversity (ecoregions, 12,056 threatened species, 'Key Biodiversity Areas' and wilderness areas) and ecosystem services (productive fisheries, and carbon services on land and sea). To be more successful after 2020, area-based conservation must contribute more effectively to meeting global biodiversity goals-ranging from preventing extinctions to retaining the most-intact ecosystems-and must better collaborate with the many Indigenous peoples, community groups and private initiatives that are central to the successful conservation of biodiversity. The long-term success of area-based conservation requires parties to the Convention on Biological Diversity to secure adequate financing, plan for climate change and make biodiversity conservation a far stronger part of land, water and sea management policies.

Global priority areas for ecosystem restoration.

Extensive ecosystem restoration is increasingly seen as being central to conserving biodiversity1 and stabilizing the climate of the Earth2. Although ambitious national and global targets have been set, global priority areas that account for spatial variation in benefits and costs have yet to be identified. Here we develop and apply a multicriteria optimization approach that identifies priority areas for restoration across all terrestrial biomes, and estimates their benefits and costs. We find that restoring 15% of converted lands in priority areas could avoid 60% of expected extinctions while sequestering 299 gigatonnes of CO2-30% of the total CO2 increase in the atmosphere since the Industrial Revolution. The inclusion of several biomes is key to achieving multiple benefits. Cost effectiveness can increase up to 13-fold when spatial allocation is optimized using our multicriteria approach, which highlights the importance of spatial planning. Our results confirm the vast potential contributions of restoration to addressing global challenges, while underscoring the necessity of pursuing these goals synergistically.

Maximizing US nitrate removal through wetland protection and restoration.

Growing populations and agricultural intensification have led to raised riverine nitrogen (N) loads, widespread oxygen depletion in coastal zones (coastal hypoxia)1 and increases in the incidence of algal blooms.Although recent work has suggested that individual wetlands have the potential to improve water quality2-9, little is known about the current magnitude of wetland N removal at the landscape scale. Here we use National Wetland Inventory data and 5-kilometre grid-scale estimates of N inputs and outputs to demonstrate that current N removal by US wetlands (about 860 ± 160 kilotonnes of nitrogen per year) is limited by a spatial disconnect between high-density wetland areas and N hotspots. Our model simulations suggest that a spatially targeted increase in US wetland area by 10 per cent (5.1 million hectares) would double wetland N removal. This increase would provide an estimated 54 per cent decrease in N loading in nitrate-affected watersheds such as the Mississippi River Basin. The costs of this increase in area would be approximately 3.3 billion US dollars annually across the USA-nearly twice the cost of wetland restoration on non-agricultural, undeveloped land-but would provide approximately 40 times more N removal. These results suggest that water quality improvements, as well as other types of ecosystem services such as flood control and fish and wildlife habitat, should be considered when creating policy regarding wetland restoration and protection.

Financing conservation by valuing carbon services produced by wild animals.

Filling the global biodiversity financing gap will require significant investments from financial markets, which demand credible valuations of ecosystem services and natural capital. However, current valuation approaches discourage investment in conservation because their results cannot be verified using market-determined prices. Here, we bridge the gap between finance and conservation by valuing only wild animals' carbon services for which market prices exist. By projecting the future path of carbon service production using a spatially explicit demographic model, we place a credible value on the carbon capture services produced by African forest elephants. If elephants were protected, their services would be worth $20.8 billion ($10.3 to $29.7 billion) and $25.9 billion ($12.8 to $37.6 billion) for the next 10 and 30 y, respectively, and could finance antipoaching and conservation programs. Elephant population growth would generate a carbon sink of 109 MtC (64 to 153) across tropical Africa in the next 30 y. Avoided elephant extinction would also prevent the loss of 93 MtC (46 to 130), which is the contribution of the remaining populations. Uncertainties in our projections are controlled mainly by forest regeneration rates and poaching intensity, which indicate that conservation can actively reduce uncertainty for increased financial and biodiversity benefits. Our methodology can also place lower bounds on the social cost of nature degradation. Poaching would result in $2 to $7 billion of lost carbon services within the next 10 to 30 y, suggesting that the benefits of protecting elephants far outweigh the costs. Our methodology enables the integration of animal services into global financial markets with major implications for conservation, local socioeconomies, and conservation.

Carbon emissions reductions from Indonesia's moratorium on forest concessions are cost-effective yet contribute little to Paris pledges.

International initiatives for reducing carbon emissions from deforestation and forest degradation (REDD+) could make critical, cost-effective contributions to tropical countries' nationally determined contributions (NDCs). Norway, a key donor of such initiatives, had a REDD+ partnership with Indonesia, offering results-based payments in exchange for emissions reductions calculated against a historical baseline. Central to this partnership was an area-based moratorium on new oil palm, timber, and logging concessions in primary and peatland forests. We evaluate the effectiveness of the moratorium between 2011 and 2018 by applying a matched triple difference strategy to a unique panel dataset. Treated dryland forest inside moratorium areas retained, at most, an average of 0.65% higher forest cover compared to untreated dryland forest outside the moratorium. By contrast, carbon-rich peatland forest was unaffected by the moratorium. Cumulative avoided dryland deforestation from 2011 until 2018 translates into 67.8 million to 86.9 million tons of emissions reductions, implying an effective carbon price below Norway's US$5 per ton price. Based on Norway's price, our estimated cumulative emissions reductions are equivalent to a payment of US$339 million to US$434.5 million. Annually, our estimates suggest a 3 to 4% contribution to Indonesia's NDC commitment of a 29% emissions reduction by 2030. Despite the Indonesia-Norway partnership ending in 2021, reducing emissions from deforestation remains critical for meeting this commitment. Future area-based REDD+ initiatives could build on the moratorium's outcomes by reforming its incentives and institutional arrangements, particularly in peatland forest areas.

Balancing agricultural production and environmental sustainability: Based on Economic Analysis From North China Plain.

The escalating trend of greenhouse gas emissions presents a dual threat to both food security and the exacerbation of global warming. Addressing this pressing issue demands concerted efforts on local and global scales to champion sustainable food production and foster environmental benefits. In 2015, a pivotal field experiment was conducted in the North China Plain, aiming to delineate the intricate balance between agricultural productivity and environmental stewardship. This study comprised eight meticulously designed treatments, incorporating two key components: the evaluation of economic and environmental parameters encompassing carbon footprint, energy consumption, and the carbon sustainability index. Notably, while the carbon sustainability index exhibited improvement, it also revealed a 9.4% increase in emissions compared to the baseline, underscoring the nuanced trade-offs involved. The findings underscored the efficacy of no-tillage (NT) practices coupled with soybean-based crop rotation, mitigating yield reduction compared to conventional tillage (RT). However, the optimal yield was observed in the RT-MW treatment, amalgamating conventional tillage with minimum tillage practices. Moreover, despite the higher cost associated with soybeans relative to milled wheat, their cultivation yielded a notable increase in net income. These compelling results advocate for the adoption of conservation agriculture as a means to optimize the delicate equilibrium between environmental preservation and economic prosperity. Furthermore, the study underscores the imperative for further research endeavors aimed at devising highly productive agricultural systems that seamlessly integrate environmental sustainability with economic viability, echoing the crucial insights gleaned from analogous contexts.

No aggregate deforestation reductions from rollout of community land titles in Indonesia yet.

In Indonesia, 60 million people live within 1 km of state forest. The government of Indonesia plans to grant community titles for 12.7 million hectares of land to communities living in and around forests. These titles allow for using nontimber forest products, practicing agroforestry, operating tourism businesses, and selective logging in designated production zones. Here, we estimate the early effects of the program's rollout. We use data on the delineation and introduction date of community forest titles on 2.4 million hectares of land across the country. We find that, contrary to the objective of the program, community titles aimed at conservation did not decrease deforestation; if anything, they tended to increase forest loss. In contrast, community titles in zones aimed at timber production decreased deforestation, albeit from higher baseline forest loss rates.

Human casualties are the dominant cost of human-wildlife conflict in India.

Reducing the costs from human-wildlife conflict, mostly borne by marginal rural households, is a priority for conservation. We estimate the mean species-specific cost for households suffering damages from one of 15 major species of wildlife in India. Our data are from a survey of 5,196 households living near 11 wildlife reserves in India, and self-reported annual costs include crop and livestock losses and human casualties (injuries and death). By employing conservative estimates from the literature on the value of a statistical life (VSL), we find that costs from human casualties overwhelm crop and livestock damages for all species associated with fatalities. Farmers experiencing a negative interaction with an elephant over the last year incur damages on average that are 600 and 900 times those incurred by farmers with negative interactions with the next most costly herbivores: the pig and the nilgai. Similarly, farmers experiencing a negative interaction with a tiger over the last year incur damage that is on average 3 times that inflicted by a leopard and 100 times that from a wolf. These cost differences are largely driven by differences in the incidence of human death and casualties. Our estimate of costs fluctuates across reserves, mostly due to a variation of human casualties. Understanding the drivers of human casualties and reducing their incidence are crucial to reducing the costs from human-wildlife conflict.Most of the tales were about animals, for the Jungle was always at their door. The deer and the pig grubbed up their crops, and now and again the tiger carried off a man at twilight, within sight of the village gates. "Tiger! Tiger!" (Rudyard Kipling, The Jungle Book, Collins Classics, 2010).

Understanding uptake of community groundwater monitoring in rural Brazil.

Resource monitoring is often cited as important for effective common pool resources management. In practice, not all monitoring interventions are successful, particularly when the resource, such as groundwater, is challenging to monitor and measure. We conducted a field experiment on groundwater monitoring in Ceará, Brazil, where communities are increasingly reliant on groundwater yet do not engage in monitoring. Despite careful implementation, uptake of monitoring within the 80 treatment communities was low. To unpack this low uptake, we conduct multimethods exploratory research. We find that uptake is less likely in communities facing high coordination costs, either within the community leadership or across the broader community. Uptake is also less likely when there are physical barriers to monitoring, when there are more substitutes for groundwater, and when there is lower variability in water availability. Our findings can inform future monitoring interventions in similar contexts worldwide.