Getting well from water
Authors: Keith J Petrie, Simon Wessely
Journal: BMJ (2004)

][6] Climate change is not merely another addition to the list of environmental health hazards each warranting separate epidemiological study and risk management.It is a complex global environmental hazard, with knock-on effects, and is unlike exposure to a dose of some specific toxic chemical or radiation.Hence the overall risk to health is more than the aggregation of itemised disease risks due to particular climatic factors.Widely evident, climate induced changes to physical and non-human biotic systems-such as glacial melt and altered seasonal timing of flowering, breeding, and migrating 7 8 -provide insight into how biogeophysical systems can become uncoupled and dysfunctional.In similar fashion, the complex array of consequences of climate change, often perturbing social systems, can have impacts on health that are not well captured by itemised tallying.Unabated climate change would impair regional food and water supplies and thereby disrupt social and economic conditionsparticularly in already poor and vulnerable populations.Conflicts would arise, migrant flows would increase, and a mix of violence, injury, infectious diseases, malnutrition, mental disorders, and other health problems would result.The relation between climate change and health is also distinctive in signifying that collectively we are on a non-sustainable path.Viewed anthropocentrically, sustainable development is about improving the quality of human life while maintaining Earth's life supporting biogeophysical systems and ecological processes.Our unprecedented impacts on the planet's climate system, ecosystems, biodiversity stocks, fresh water supplies, and other systems indicate that we are now eroding natural capital globally. 9ecent advances in understanding climate change and its impacts highlight the need for extraordinary and rapid reductions in emissions of carbon dioxide.Russia's recent decision to ratify (and thus activate) the Kyoto protocol is heartening but insufficient.More developed countries must adopt Britain's commitment to stepwise halving of national emissions by 2050.The technical knowledge required to meet world energy needs, while radically reducing greenhouse emissions, already exists. 10However, both biosphere and human society are complex dynamic systems, and climate change therefore cannot be remedied by a single intervention.We need a multifaceted approach that encompasses decreased waste generating consumerism, improved energy efficiency, reduced deforestation, and greater use of non-fossil fuels.As our understanding of the biosphere and climate system grows, we see that the main issues are not about such things as fine tuning the economic modelling of future emission trajectories, or noting the palaeoevidence that Earth's climate is ever changeable.The real challenge is to understand the complexity and uncertainties of changes in Earth's natural systems, the likely human impacts (and adaptive strategies to lessen those impacts) and the fundamental significance of human induced climate change in relation to the great task of achieving a sustainable way of living.