Payments for ecosystem services and their effects on health and wellbeing: a systematic review.

Payments for ecosystem services, often funded through carbon offsetting, seek to improve environmental conservation and reduce poverty by paying individuals or communities for maintaining the environment. Following previous registration (PROSPERO CRD42024591264), we searched the EconLit, Medline, CAB Abstracts and Global Health (accessed via Web of Science), GreenFILE, and 3ie databases and grey literature. We systematically reviewed quantitative and qualitative studies assessing the effects of payments for ecosystem services on the health or subjective wellbeing of individuals. We assessed risk of bias using Risk of Bias tool for randomised trials 2, Risk Of Bias In Non-randomized Studies-of Interventions, and Critical Appraisal Skills Programme, with certainty assessed using Grading of Recommendations Assessment, Development, and Evaluation. Synthesis without meta-analysis, effect direction plots, and thematic synthesis were conducted. 19 (7·7%) of 5615 screened articles met the inclusion criteria, with very high or high risk of bias in most studies. Two randomised controlled trials, eight natural experiments, and nine qualitative studies were included. The synthesis without meta-analysis and effect direction plots indicated heterogeneous effects, with both beneficial and adverse effects across outcomes. Thematic synthesis suggested that payment for ecosystem services resources were often invested in health care. The reported benefits included perceived gains in happiness and pride linked to conservation activities. However, the participants also reported stress related to conditionalities or delayed payment. Community-level payments compared with individual-level payments appeared more conducive to equitable and positive health outcomes. The effects of payments for ecosystem services on health and subjective wellbeing were highly variable, depending on context and programme design. Available evidence remains scarce and has very low certainty; therefore, robust health evaluations are needed.