Climate Change and Health Climate change is the biggest global health threat of the 21st century. Health is and will be affected by the changing climate through direct impacts (heat waves, droughts, heavy storms, and sea-level rise), and indirect impacts (vector-borne and airways diseases, food and water insecurity, undernutrition, and forced displacements). PAHO's Climate Change and Health Program aims to prepare health systems through early warning, better planning and the implementation of prevention and adaptation measures, but also by reducing the emissions of gases that cause climate change - within the health sector and with other sectors. Key facts Climate change is not only a problem for future generations – it's already happening. Higher mean temperatures are recorded each year, and more people are being affected by disasters, climate-sensitive diseases and other health conditions. Climate change exacerbates some existing health threats and creates new public health challenges. Worldwide, only considering a few health indicators, additional 250,000 deaths per year will occur in the next decades as a result of climate change. The health sector has an important role to play in reducing greenhouse gas emissions that are the cause of climate change. Investments to “greening” health care facilities – such as the use of solar panels, energy efficient equipment and waste manag