Global Environmental Change and Human Health:. Impact Assessment, Population Vulnerability, and Research Priorities

Abstract

ABSTRACT

The scale of environmental hazards to human population health is increasing. For the first time, the human species is perturbing various natural systems at the global level. Over many millennia, humans have often degraded local ecosystems, and their societies then usually suffered or moved. What differs in today’s world is the global, systemic, scale of human impact. This reflects the aggregate impact of rapidly increasing population size and an energy-intensive high-throughput linear consumer economy. In consequence, we are now encountering anthropogenic changes in the composition of the world’s lower and middle atmospheres and the worldwide depletion of other natural systems (e.g., soil fertility, aquifers, ocean fisheries, and biological diversity).

We have long overlooked the fundamental infrastructural importance to human health of the biosphere’s natural systems. Yet, these are the life-support systems upon which the sustained health of populations depends. In many respects, the potential health risks from global environmental change are therefore qualitatively different from the well-known, locally confined environmental risks to health from direct-acting toxic pollutants. Disruption of natural biophysical systems jeopardizes human health by a range of direct and indirect, immediate and delayed mechanisms. These entail major implications for the longer-term sustainability of human population health. We therefore must extend our health risk assessment concepts and methods to accommodate scenario-based forecasting of health impacts. There is need for an expanded transdisciplinary research effort that would include the development of new and better modelling and predictive techniques. These research methods and the communication of research results to public and policymaker must accommodate an unusual mix of complexity, uncertainty, and futurism.

The extent and profile of health impacts from global environmental change will vary around the world. In general, poor, restricted, and isolated populations will be the most vulnerable. The combined impacts of climate change, freshwater shortages, and land degradation may impair agricultural productivity most in subtropical and semi-arid regions where food insecurity is already prevalent. Clearly, there are complex political and ethical challenges that accompany the challenges to science.