The rapid growth in noncommunicable diseases (NCDs), including injury and poor mental health, in low- and middle-income countries and the widening social gradients in NCDs within most countries worldwide pose major challenges to health and social systems and to development more generally. As Earth's surface temperature rises, a consequence of human-induced climate change, incidences of severe heat waves, droughts, storms, and floods will increase and become more severe. These changes will bring heightened risks to human survival and will likely exacerbate the incidence of some NCDs, including cardiovascular disease, some cancers, respiratory health, mental disorders, injuries, and malnutrition. These two great and urgent contemporary human challenges-to improve global health, especially the control of NCDs, and to protect people from the effects of climate change-would benefit from alignment of their policy agendas, offering synergistic opportunities to improve population and planetary health. Well-designed climate change policy can reduce the incidence of major NCDs in local populations.