Michael B. Mascia

Sustainability science and sustainable development policies increasingly recognize the contribution of biodiversity conservation to human well-being. However, understanding of the linkages between conservation and human well-being remains limited. Empirical evidence on the existence, magnitude and variation in causal pathways is fragmented, hampering decision-makers’ ability to design conservation interventions that also support human well-being. Here we present a conceptual framework that identifies five major pathways through which conservation interventions affect human well-being: 1) governance, 2) ideas and information, 3) conservation infrastructure, 4) ancillary opportunities, and 5) ecosystem services. These pathways may interact, creating novel synergies and trade-offs, scale-dependency, and distributive effects that shape an intervention’s social impact. Use of such a multi-causal framework can help avoid skewing policy decisions and investments toward any one pathway. Recognition of the diverse mechanisms linking conservation and human well-being allows scholars and practitioners to better assess the contribution of biodiversity conservation to global sustainability.

Marine protected areas (MPAs) are widely adopted to conserve marine biodiversity, yet their distributional impacts on resource-dependent communities remain underexplored. This study investigates socioeconomic inequality linked to MPAs in eastern Indonesia using a quasi-experimental design and multi-round household surveys of over 10,000 households across 180 coastal settlements in 10 MPAs (2010-2017). We assess poverty through objective (asset-based index) and subjective (perceived economic trends) measures. Findings reveal overall poverty reduction and persistent pre-existing inequalities by gender, age, occupation, and tenure rights. MPAs did not cause short-term economic losses or widen objective inequality but constrained perceived economic improvement, particularly among female-headed households. Community engagement moderated these effects: gender disparities were greater where female participation in groups was low. These findings suggest that promoting inclusive participation can help ensure more equitable conservation outcomes.

Meeting the Paris Agreement to limit global warming to “well below 2 °C” requires a radical acceleration of action, as the global economy is decarbonising at least five times too slowly. Tipping points, where low-carbon transitions become self-propelling, could be key to achieving the necessary acceleration. We deem these normatively ‘positive’, because they can limit considerable, inequitable harms from global warming and help achieve sustainability. Some positive tipping points, such as the UK’s elimination of coal power, have already been reached at national and sectoral scales. The challenge now is to credibly identify further potential positive tipping points, and the actions that can bring them forward, whilst avoiding wishful thinking about their existence, or oversimplification of their nature, drivers, and impacts. Hence, we propose a methodology for identifying potential positive tipping points, assessing their proximity, identifying the factors that can influence them, and the actions that can trigger them. Building on relevant research, this ‘identifying positive tipping points’ (IPTiP) methodology aims to establish a common framework that we invite fellow researchers to help refine, and practitioners to apply. To that end, we offer suggestions for further work to improve it and make it more applicable.

Community‐based natural resource management is a common strategy for conserving biodiversity, but little is known about how such initiatives can scale appropriately and widely. We interviewed 80 experts across 5 widely adopted community‐based initiatives (in Chile, Nepal, Namibia, Madagascar, and Fiji) to understand their perspectives on the drivers of adoption and spread. We used general elimination methodology and diffusion of innovation theory to identify and rule out possible explanations. Factors consistently considered influential were economic and social benefits, compatibility with needs, support and facilitation by extension agencies, and the presence of international organizations. Initiatives aiming to scale should be designed to be flexible and aligned with adopters’ needs, and external organizations should coordinate resources for scaling out. Dependence on external support underscores the need for quality assistance, good practices by external actors, and understanding power relations and fairness, as well as the need to temper donor and policy expectations of scaling beyond supported and appropriate sites.

Community-based natural resource management is a common strategy for conserving biodiversity, but little is known about how such initiatives can scale appropriately and widely. We interviewed 80 experts across 5 widely adopted community-based initiatives (in Chile, Nepal, Namibia, Madagascar and Fiji) to understand their perspectives on the drivers of adoption and spread. We used General Elimination Methodology and Diffusion of Innovation theory to identify and rule out possible explanations. Factors consistently considered influential were economic and social benefits; compatibility with needs; support and facilitation by extension agencies; and the presence of international organisations. Initiatives aiming to scale should be designed to be flexible and aligned with adopters’ needs and external organisations should coordinate resources for scaling out. Dependence on external support underscores the need for quality assistance, good practices by external actors, and understanding power relations and fairness, as well as the need to temper donor and policy expectations of scaling beyond supported and appropriate sites.

Marine protected areas (MPAs) are widely used for ocean conservation, yet the relative impacts of various types of MPAs are poorly understood. We estimated impacts on fish biomass from no-take and multiple-use (fished) MPAs, employing a rigorous matched counterfactual design with a global dataset of >14,000 surveys in and around 216 MPAs. Both no-take and multiple-use MPAs generated positive conservation outcomes relative to no protection (58.2% and 12.6% fish biomass increases, respectively), with smaller estimated differences between the two MPA types when controlling for additional confounding factors (8.3% increase). Relative performance depended on context and management: no-take MPAs performed better in areas of high human pressure but similar to multiple-use in remote locations. Multiple-use MPA performance was low in high-pressure areas but improved significantly with better management, producing similar outcomes to no-take MPAs when adequately staffed and appropriate use regulations were applied. For priority conservation areas where no-take restrictions are not possible or ethical, our findings show that a portfolio of well-designed and well-managed multiple-use MPAs represents a viable and potentially equitable pathway to advance local and global conservation.

The growing prevalence of marine protected areas (MPAs) to conserve marine biodiversity has been shown to have a considerable impact on resource-dependent coastal communities. Despite the existence of the burgeoning literature studying MPA aggregate effects on human well-being, there is limited evidence related to the equality of marine conservation impacts across societal groups. In this paper, we study the distributional socioeconomic impacts of MPAs through the lens of poverty exposure—a crucial aspect of inequality relevant to coastal communities in developing countries. We implement a quasi-experimental design using a multi-round household survey in eastern Indonesia, that covers over 10,000 households located in 180 treated and control coastal settlements across 10 MPAs between 2010 and 2017. To capture some of the multiple dimensions of human well-being, we used both objective (asset-based poverty index) and subjective (household’s perceived economic trends) measures of poverty. Our analysis documents a positive poverty-alleviation trend in the studied seascapes, as well as the existence of pre-existing economic inequality across major subgroups defined by gender, age cohort, fishing occupation, and tenure-rights ownership. We also find that the implementation of MPAs did not incur a significant short-term loss in objective economic well-being as documented elsewhere or materially increase inequality between social groups. Nonetheless, MPAs appeared to be constraining perceived economic improvement, particularly in female-headed households. Importantly, we find that community engagement is an influential factor moderating this impact heterogeneity; MPAs exacerbated the gender-based inequality in perceived economic improvement in settlements where female household heads participated less in community groups at baseline but not in more active participation settlements. Our results suggest that active community participation by marginalized groups could foster more objective economic well-being as documented elsewhere or materially increase inequality between social groups. Nonetheless, MPAs appeared to be constraining perceived economic improvement, particularly of female-headed households. Importantly, we find that community engagement is an influential factor moderating this impact heterogeneity; MPAs exacerbated the gender-based inequality in perceived economic improvement in settlements where female household heads participated less in community groups at baseline but not in more active participation settlements. Our results suggest that active community participation by marginalized groups could foster more equitable distribution of conservation impacts and, therefore, should be promoted by MPA implementing and management agencies. e equitable distribution of conservation impacts and, therefore, should be promoted by MPA implementing and management agencies. JEL Classifications: Q25, Q57, O13, O15

Background: Nature-based interventions (NbIs) for climate change mitigation include a diverse set of interventions aimed at conserving, restoring, and/or managing natural and modified ecosystems to improve their ability to store and sequester carbon and avoid greenhouse gas (GHG) emissions. Recent projections estimate that terrestrial NbIs can lead to more than one-third of the climate change mitigation necessary to meet the Paris Climate Agreement by 2030. Further, these interventions can provide co-benefits in the form of social and ecological outcomes. Despite growing recognition of the potential benefits, a clear characterization of the distribution and occurrence of evidence which supports linkages between different types of NbIs and outcomes for climate change mitigation, ecosystems, and people remains poorly understood. Methods: This systematic map assesses the evidence base on the links between NbIs and climate change mitigation, social, and ecological outcomes in tropical and subtropical terrestrial regions. We searched three bibliographic databases, 65 organization websites, and conducted backward citation chasing within 39 existing evidence syntheses to identify relevant articles. Additionally, we reached out to key informants for additional sources of evidence. We then used machine learning to rank returned results by relevance at the title and abstract stage and manually screened for inclusion using predefined criteria at the title, abstract, and full text stages. We extracted relevant meta-data from included articles using an a priori coding scheme. Lastly, we conducted a targeted, complementary search to identify relevant review and synthesis articles to provide broader context for the findings of the systematic map. Review findings: We included 948 articles in this systematic map. Most of the evidence base (56%) examined links between protection, natural resource management, and restoration interventions with changes to ‘proxy’ outcomes for climate change mitigation (changes to land condition, land cover, and/or land use). Other areas with high occurrence of articles included linkages between interventions within natural resource management and trees in croplands categories and changes to aboveground carbon storage and/or sequestration (17% of articles). A key knowledge gap was on measured changes in GHG emissions across all intervention types (6% of articles). Overall, articles in the evidence base did not often assess changes in co-benefits alongside direct or indirect changes for climate change mitigation (32%). In most cases, the evidence base contained studies which did not explicitly test for causal linkages using appropriate experimental or quasi-experimental designs. Conclusions: The evidence base for NbIs is significant and growing; however, key gaps in knowledge hamper the ability to inform ongoing and future investment and implementation at scale. More comprehensive evidence is needed to support causal inference between NbIs and direct outcomes for climate change mitigation to better determine additionality, permanence, leakage, and other unintended consequences. Similarly, priorities emerging from this map include the need for coordinated and harmonized efforts to collect diverse data types to better understand whether and how other outcomes (e.g. social, ecological) of NbIs can be achieved synergistically with mitigation objectives. Understanding potential benefits and trade-offs of NbIs is particularly urgent to inform rapidly expanding carbon markets for nature.