Tree cover loss in the Americas: a critical indicator linking climate mitigation and planetary health.

Trees and forests are vital carbon sinks and essential resources for communities across the Americas, yet persistent tree cover loss threatens climate stability and human health. Between 2001 and 2022, global tree cover loss exceeded 459 million hectares, with 40% occurring since the Paris Agreement. Grounded in the Planetary Health framework, this Viewpoint presents tree cover loss as a sentinel indicator linking climate mitigation failures to health outcomes. Our conceptual framework identifies five interconnected pathways: climate regulation disruption, ecosystem service degradation, livelihood and resource loss, infectious disease risk alteration, and cultural-psychosocial impacts. These pathways disproportionately burden Indigenous communities and lower-income populations who contribute least to deforestation. We outline opportunities for cross-boundary conservation approaches recognising Indigenous land rights, enhanced monitoring systems, and agricultural policies delivering climate-health co-benefits. By framing tree cover loss as both an environmental and public health emergency, this framework guides more effective and equitable interventions across the region.