Health of People, Places and Planet. Reflections based on Tony McMichael’s four decades of contribution to epidemiological understanding

Abstract

The most serious potential consequence of global environmental change is the erosion of Earth’s life-support systems. Yet, curiously, the nature of this threat to the health and survival of the world’s living species - including our own - has received little attention. Over aeons, the evolution of life has gradually transformed the environment that clothes the planet’s surface. The lower atmosphere’s composition has changed; stratospheric ozone has formed from oxygen emitted by plants; soil has been created by oxidation, plants and microbes; and forests speed the recirculation of rainwater. Life’s genetic diversity confers a capacity for adaptive change. However, this fabric of lifesupporting mechanisms is now starting to unravel, in a brief geological moment, as the cumulative global impact of human activity escalates.