From advocacy to action: Projecting the health impacts of climate change

Mitigating climate change by reducing greenhouse gas emissions has many health co-benefits and is a top public health priority. Policies to limit emissions are associated with improvements across a wide range of public health outcomes, including, among other impacts, obesity, acute respiratory infections among children, and ischaemic heart disease in adults [1]. However, recognition that climate change is already underway has led to an increasing focus on adaptation. Studies projecting the impacts of future climate change on health date back to the late 1980s, and their number has grown substantially in recent years. Climate change impact assessments generally use the output of global climate models (GCMs). Here, we profile, and suggest means for addressing, the challenges associated with the use of GCM projections for impact studies to inform adaptation. GCMs provide projections of the climate at a typical resolution of about 100 km2. Such low precision is of limited use to decision-makers trying to determine how climate change might affect their particular district, town, or even country. Often, a regional climate model is employed to ‘downscale’ the output of the global model to a resolution considered more useful for practical applications. Climate model output can then be used to drive disease models or to investigate the risks of surpassing health-relevant climate thresholds in the future