Human Health in a Changing Climate: Past, Present, and Future

Abstract

TM4-O-01 Session Title: Climate Change and Human Health Climate has changed more rapidly over the past decade or so than was foreseen in previous modelled forecasts. Some of the phenomena (eg, melting glaciers and changes to rainfall regimens) previously assumed to lie decades ahead now appear to be underway. The recent apparent increase in frequency and intensity of some extreme weather events portend significant risks to human well-being and accord with the expectation that climate will become. Interest in the relationship between climate and health has a long history. In the fifth century BC, Hippocrates related epidemics to seasonal weather changes. In 1877, severe drought affected India, China, and other areas, causing over 20 million estimated deaths from famine and disease. However, the health impacts of human-induced global climate change seem likely to occur on a different spatial scale and with different temporal dynamics from those of natural climate variability. This emerging “global” environmental hazard poses important conceptual and methodologic challenges to epidemiologists, in identifying, forecasting, and proposing ways of ameliorating the health risks of climate change. Recent evidence indicates that more variable with global warming. Such extreme events are illustrated by 1) Hurricane Katrina in 2005, which killed over 1000 people, displaced over a million people, and spread oil, toxins, and microorganisms throughout the U.S. Gulf Coast, and 2) the 2003 heat wave that killed 35,000 people in western Europe alone and caused severe economic losses. Other recent weather disasters (eg, floods in Central Europe in 2002 and 2005) and record high temperatures in many parts of the world (eg, severe heat waves in Australia in 2004 and 2005) may have incorporated an increasing influence of climate change. Further, other evidence indicates that the transmission of infectious diseases (eg, malaria, schistosomiasis, and Lyme disease) may have increased in some parts of the world in association with warming. While developed countries may find it difficult to cope with the impacts of occasional extreme manifestations of climate change, developing countries face more difficulties in defining, assessing and, in particular, adapting to these changes. In light of these emerging trends, more investment in research and policy development is needed in relation to both mitigation and adaptation. The former is essential to minimize future health (and other) impacts, and the latter is essential to reduce the risk of health impacts, which cannot be avoided in the near to medium term. To engage in this now-important topic area, epidemiologists will need to generate skills and methods in 1) interdisciplinary research (including in connection with some unfamiliar earth-system science topics); 2) assessing causal relationships within a system-change context; and 3) scenario-based risk assessment of future health risks. The formal evaluation of community-based adaptive (coping) strategies will also be important.