Conference Agenda

Market-based policies for forest conservation have been proposed as a low-cost climate solution, yet past policies have failed to meaningfully reduce deforestation. Here, we explore this tension using a theoretically-founded, econometric model of land users' deforestation decisions. We find that payments of $193/tCO2 would reduce deforestation by 96%. However, targeting is essential: untargeted payments cost trillions with only 1% additionality. Even if targeted by highly informed policymakers, information asymmetries will undermine the efficiency of payments by discouraging low-cost abatement while paying for non-additional conservation. Carbon taxes do not require targeting, but would impose large costs in the poorest countries. Careful policy design will thus be necessary to ensure the world makes efficient and equitable use of this important natural climate solution.

Although incentives frequently overlap with direct land management regulations, the cost effective

design of payment for ecosystem services (PES) in the presence of command-and-control regulation remains poorly understood. We study this question using Brazil’s Reflorestar program, a large-scale PES for forest restoration that operates under the Forest Code, which requires landowners to maintain native vegetation on a share of their land. We analyze enrollment patterns, estimate program additionality using staggered difference-in-differences, and estimate willingness to accept (WTA) using plausibly exogenous spatial variation in offered payments. We find positive reforestation impacts with magnitudes and costs comparable to many avoided deforestation initiatives. We also examine strategies to increase cost-effectiveness, finding that in the presence of overlapping command-and-control regulation, cost-effectiveness of restoration PES can be substantially improved by targeting private rural properties that are already compliant with the Forest Code or are in municipalities with greater enforcement capacity.

In an effort to redress historical dispossession and support Indigenous self-determination, multiple countries have adopted policies that return land back to Indigenous peoples. Such land restitution programs are partially motivated by a hope that restitution will enable Indigenous communities to determine land use in ways that will also generate public environmental benefits. However, little is known about how Indigenous communities change land use after land is returned to their stewardship. Here we study the land use impacts of a Chilean restitution program that, between 1994 and 2023, returned more than 200,000 hectares of land to Mapuche communities. Using a difference-in-differences research design, we find that land restitution led to more grasslands, a traditional Mapuche use of land, and fewer non-native forest plantations, a use of land that Mapuche have frequently protested against. However, restitution did not change the extent of natural forests. Given this reconfiguration in land use, restitution has led to insignificant changes in carbon sequestration or biodiversity. Our results complicate common narratives that Indigenous land reform will always yield improvements in environmental outcomes. Careful consideration of the local cultural context and the legacies of dispossession can help set appropriate expectations for the environmental co-benefits of these reforms.

Land restoration is crucial for reversing pressing environmental degradation. Limited funding demands targeted and effective restoration interventions, yet it remains highly uncertain when and where interventions are successful. Using a rigorous global impact evaluation of 1,483 restoration sites, we find that the majority of projects (72%) achieve an improvement in satellite-derived vegetation greenness (median effect +24%) compared to what would have happened without intervention. Our results suggest that restoration success depends on governance mechanisms, access to resources, and restoration approach. We find that implementing organizations are key restoration drivers, while collectively owned sites require enabling conditions to ensure effective governance. Restoration can succeed across diverse ecosystems, provided that organizational capacity, governance structures, and restoration approach are aligned with the needs of local people.