Peer-reviewed publications

The conservation community needs to improve the quality and quantity of evidence to address urgent and complex environmental challenges. The growth of Upstream Conservation Initiatives (UCIs) such as those designed to eliminate deforestation by shifting consumer or corporate behavior, exemplify the tension between the urgency to act and the need to build evidence to enable progressive improvements in implementation. These initiatives—often led by non-governmental organizations (NGOs)—are rarely evaluated rigorously in terms of their causal effect on intended outcomes, contributing to the evidence deficit. Impact evaluations have been useful tools to analyze effectiveness and build evidence in other fields. However, they are seldom used in the conservation field broadly or in UCIs specifically. To help practitioners involved in UCIs make better use of these tools, we introduce the field of impact evaluation, its core concepts, and how it contrasts with and complements traditional performance measurement approaches. Using these concepts, we propose a guidance process which can be used by practitioners at the project design phase to weigh tradeoffs and consider the most appropriate impact evaluation methodologies. We then use this guidance process to analyze two UCIs implemented by an NGO in Indonesia. Through these case studies we show how impact evaluation concepts could have been employed in project design to improve implementation and promote progressive learning, even if actual impact evaluations were infeasible. We conclude by proposing recommendations on how implementers, donors, and academia can build off these ideas to improve learning and strengthen the evidence base.

Community-based conservation has been increasingly recognized as critical to achieve both conservation and socio-economic development goals worldwide. However, the long-term sustainability of community-based conservation programs is dependent on a broadly shared perception among community members that management actions are achieving their stated goals. Thus, understanding the underlying factors driving differences in perceptions of management effectiveness can help managers prioritize the processes and outcomes most valued by resource users and thereby promote sustained support for conservation efforts. Here, we utilize large-scale interview survey data and machine learning to identify the factors most strongly associated with differences in perceived management effectiveness between resource users engaged in marine community-based conservation programs in Kenya and Tanzania. Perceptions of management effectiveness were generally favorable in both countries, and the most important predictors of positive perceptions were associated with community and individual empowerment in resource management and use, but within disparate focal domains. Improved perceptions of management effectiveness in Kenya were closely related to increases in women’s empowerment in community-based conservation programs, while inclusionary and transparent governance structures were the most important factors driving improved perceptions in Tanzania. Additionally, the strongest predictors of differences between individuals in both countries often interacted synergistically to produce even higher rates of perceived effectiveness. These findings can help future initiatives in the region tailor management to match community-level priorities and emphasize the need for community-based conservation programs to understand local context to ensure that metrics of “success” are aligned with the needs and desires of local resource users.

Based on an extensive model intercomparison, we assessed trends in biodiversity and ecosystem services from historical reconstructions and future scenarios of land-use and climate change. During the 20th century, biodiversity declined globally by 2%-11% estimated by a range of indicators. Provisioning ecosystem services increased several-fold while regulating services decreased moderately. Going forward, policies towards sustainability have the potential to slow biodiversity loss resulting from land-use change and the demand for provisioning services, while reducing or reversing declines in regulating services. However, negative impacts on biodiversity due to climate change appear poised to increase, particularly in the higher emissions scenarios. Our assessment identifies remaining modelling uncertainties but also robustly shows that renewed policy efforts are needed to meet the goals of the Convention on Biological Diversity.

Forestalling the decline of global biodiversity requires urgent and transformative action at all levels of government and society, particularly in the Arctic Ocean and adjacent seas where rapid changes are already underway. Amid growing scientific support and mounting pressure, the majority of nations have committed to the most ambitious conservation targets yet. However, without an approach that inclusively and equitably reconciles conservation and sustainable ocean use, these targets will likely go unmet. Here, we present ArcNet: a network design framework to help achieve ocean-scale, area-based marine conservation in the Arctic. The framework is centred around a suite of web-based tools and a ~ 5.9 million km2 network of 83 priority areas for conservation designed through expert-driven systematic conservation planning using conservation targets for over 800 features representing Arctic biodiversity. The ArcNet framework is intended to help adapt to new and emerging information, foster collaboration, and identify tailored conservation measures within a global context at different levels of planning and implementation.

Values play a significant role in decision-making, especially regarding nature. Decisions impact people and nature in complex ways and understanding which values are prioritised, and which are left out is an important task for improving the equity and effectiveness of decision-making. Based on work done for the IPBES Values Assessment, this paper develops a framework to support analyses of how decision-making influences nature as well as whose values get prioritised. The framework is used to analyse key areas of environmental policy: a) the present model for nature protection in market economies, b) the role of valuation in bringing nature values into decisions, and c) values embedded in environmental policy instruments, exemplified by protected areas for nature conservation and payments for ecosystem services. The analyses show that environmental policies have been established as mere additions to decision-making structures that foster economic expansion, which undermines a wide range of nature's values. Moreover, environmental policies themselves are also focused on a limited set of nature's diverse values. This article is part of the theme issue ‘Bringing nature into decision-making’.

Deforestation impacts the ecosystem services provided by downstream coral reefs to coastal communities in multiple ways, such as through increased sedimentation and nutrification. However, connections between terrestrial and marine ecosystems are generally assessed at a single scale and from an ecological perspective alone, limiting our understanding of how watershed management affects the benefits accrued by coastal communities at different scales. Here we explore how ecological and societal benefits of watershed interventions (restoration, protection and sustainable agriculture) differ when considered regionally versus nationally in the Mesoamerican Reef region, by using linked land–sea ecosystem service models. Results from a regional approach prioritize implementing interventions in larger multinational watersheds, leading to neighbouring nations benefiting from increased sediment retention and healthy corals. For the national prioritization approach, selecting for smaller watersheds within individual countries resulted in more societal benefits, particularly increased coastal protection and nature-based tourism, at the cost of improved coral health for neighbouring nations. We demonstrate how planning at multiple scales across the region can improve ecosystem and societal benefits, resulting in win–win outcomes.

Achieving global climate, development, and biodiversity goals will require bringing conservation interventions to scale in suitable contexts and with appropriate timing. Practitioners and policymakers have a range of actions available to influence where, when, and by whom an initiative is adopted. Yet, to make effective management decisions, they must have a clear view of the current trajectory towards scaling goals. The non-linearity and variability of scaling processes has, however, hindered forecasting of adoption trends and environmental outcomes. Here, we adapt models of disease transmission to present a simple and flexible modeling structure for forecasting the adoption of conservation initiatives. We tested this framework on empirical adoption data from 19 distinct initiatives. Specifically, we fit the shape of the adoption timeline during the first half of each initiative, estimating the rates of independent uptake and social transmission up to that point. Forecasting the latter 50% of the timeline of cumulative adoption using just these two parameters resulted in an out-of-sample average error of 15.9% across all observations, indicating that this simple formulation captures much of the data-generating process. In one case, we included data on conservation abandonment, extending the cumulative adoption model to estimate the dropout rate and predicting net adoption with an average error of 19.6%, also indicative that this model captures the empirical process reasonably well. We caution against using such models for long-term forecasts, as they are sensitive to multiple assumptions, but instead advocate for their use in adaptive management. Iterative comparisons of forecasts allow users to retrospectively evaluate the impact of decisions and investments. When combined with estimates of environmental outcomes, our framework may provide a comprehensive modeling strategy for identifying targeted management actions and forecasting the impact of conservation projects while considering dynamic social processes.

The United Nations General Assembly adopted a resolution in 2022 that formally recognizes that there is a universal human right to a clean, healthy and sustainable environment. Yet there is evidence that human rights impacts associated with the degradation of the ocean environment are accelerating. In this perspective, we highlight how the recognition of the human right to a healthy environment can catalyze ocean action and transform ocean governance. In particular, it can do so through 1) catalyzing marine protection and increasing accountability through clarifying state obligations, 2) improving the inclusiveness of ocean governance, including through prioritizing and empowering groups in situations of vulnerability, and 3) enhancing ocean economy practices through clarifying private sector responsibilities. To those ends, there is an urgent need to move from recognition to implementation in order to protect both current and future generations’ right to a clean, healthy, and sustainable ocean.

Countries are expanding marine protected area (MPA) networks to mitigate fisheries declines and support marine biodiversity. However, MPA impact evaluations typically assess total fish biomass. Here, we examine how fish biomass disaggregated by adult and juvenile life stages responds to environmental drivers, including sea surface temperature (SST) anomalies and human footprint, and multiple management types at 139 reef sites in the Mesoamerican Reef (MAR) region. We found that total fish biomass generally appears stable across the region from 2006 to 2018, with limited rebuilding of fish stocks in MPAs. However, the metric of total fish biomass masked changes in fish community structure, with lower adult than juvenile fish biomass at northern sites, and adult:juvenile ratios closer to 1:1 at southern sites. These shifts were associated with different responses of juvenile and adult fish to environmental drivers and management. Juvenile fish biomass increased at sites with high larval connectivity and coral cover, whereas adult fish biomass decreased at sites with greater human footprint and SST anomalies. Adult fish biomass decreased primarily in Honduran general use zones, which suggests insufficient protection for adult fish in the southern MAR. There was a north–south gradient in management and environmental drivers, with lower coverage of fully protected areas and higher SST anomalies and coastal development in the south that together may undermine the maintenance of adult fish biomass in the southern MAR. Accounting for the interplay between environmental drivers and management in the design of MPAs is critical for increasing fish biomass across life history stages.

Global food loss and waste has not abated despite tremendous efforts to reduce it. Food wastage has profound consequences including our inability to combat hunger, contributions to unsustainable resource exploitation, and represents about half of the greenhouse gas emissions of the entire agrifood system. Mitigating the problems for a sustainable future requires managing food waste using the most appropriate approach. Upcycling food waste to animal feed is an essential strategy to capture the greatest value compared with other recycling options. The overall goal of this critical analysis is to provide evidence that upcycling of many food waste sources to animal feed can be successfully achieved in support of sustainable productivity. We describe multiple dimensions of reducing emissions and improving resource utilization efficiency, characterize the suitability of various food waste sources and limitations as animal feed, and describe the needs for de-risking strategies, overcoming legislative bottlenecks, and filling knowledge gaps to accelerate greater use of this high impact sustainability strategy.