The escalating worldwide emission of greenhouse gases (GHG) due to recent rapid increases in fossil fuel combustion, agricultural practices and land-clearing, is changing the world’s climate system. There is no longer any serious scientific debate about this basic process. The accumulated impact of human economic activities has begun to change the world’s climate, and this process will continue and escalate over the coming decades. Climate change, in turn, is altering patterns of climate-related environmental exposure to heat, rainfall and extreme weather events, disrupting climate-sensitive ecosystems, and contributing to social and economic disruptions.
These changes in climatic conditions, and the resultant changes in environmental, ecological and social systems, pose a range of risks to human health: both directly and indirectly; both now and in future (McMichael and Woodruff, 2006). While some health benefits may arise in some regions, such benefits are likely to be temporary or nullified by the encroachment of other adverse health impacts. The health risks include the impacts of heat-waves and other extreme weather events, changes to air quality, the geography and seasonality of various infectious diseases, local food yields, freshwater supplies, the general vitality of ecosystems and the flow of their services, and the underpinning of diverse livelihoods.
Globally, the emerging situation poses more than an environmental problem; it poses a political and moral problem. The great majority of the greenhouse gas emissions to date have come from today’s developed countries, whereas most of the adverse health risks, by dint of population location and vulnerability, occur in developing countries. Sub-Saharan Africa, hugely dependent on rain-fed agriculture and already widely impoverished, under-fed and ravaged by infectious diseases (especially HIV/AIDS, tuberculosis, malaria and child diarrhoea), is especially vulnerable to the environmental and social stresses of climate change (especially the expected decline in rainfall).
True primary prevention depends on a massive international effort to curtail greenhouse gas emissions and, hence, climate change. This looms as a huge and unprecedented international challenge — and, as yet, few countries are making a serious effort to help slow the process. Australia has been one of the slowest of the developed countries to make a commitment to genuine internationalism in this matter.
No matter what degree of international commitment is achieved over the coming decade, the world is already committed to at least another half-to-one degree centigrade rise in average surface temperature. This reflects the enormous inertia in the climate system and the associated slow redistribution of excess energy (heat) throughout the world’s oceans. Therefore, every country now needs to also take secondary preventive action — that is, to identify the main health risks confronting their population, the most vulnerable sections of the population, and the appropriate interventions to reduce those health risks.
Many of the health risks will be best addressed by enlightened inter-sectoral policy and action. The threat of serious illness and death due to extremes of heat (such as the notorious August 2003 heat-wave in Europe) can be reduced by simple, immediate measures — such as early warnings for such events (by meteorology agencies), special provision for (or attention to) the elderly and sick, and public education about clothing, staying indoors and household ventilation. However, to render communities more ‘heatwave-proof’ in the longer term will require more wide-ranging and farsighted changes to urban layout, transport systems, housing design, and the nurturing of green space.
In general, whether in Australia or elsewhere, it will be important for governments and communities to think in imaginative and multi-sectoral ways about how to adjust living environments, physical infrastructure, ecosystem management, social institutions and public information flows in order to achieve more resilience against the shocks and stresses of climate change.
Meanwhile, the formal health sector has multiple important roles to play. These are:
1. Disease prevention
Examples are: vaccination programs; ensuring the safety of water supplies and food; and education of doctors to facilitate their counselling of (especially the high-risk) patients and families.
2. Public education
Relevant topics: the nature of climate change; why it poses risk to health; what particular risks apply within Australia; where to obtain further information.
3. Disaster Preparedness
Climate-related disasters include bushfires, floods, droughts, cyclones and hail-storms. Hospitals and emergency services need to be equipped, trained and ready to act. Local and national response-coordination systems are essential.
4. Early warning systems
Linkages with the meteorological services will enable advance warning of heat-waves, other extreme weather events, and slower climate-change processes such as drying and droughts. All embody serious risks to health. It should also become possible to provide information about impending changes in the probability of occurrence of outbreaks of various infectious diseases, including dengue fever and Ross River Virus disease.
5. Surveillance of disease occurrence and disease risk factors
Improved surveillance systems — either population-based or at sentinel sites — will enhance our understanding of relationships between climatic conditions and health outcomes, and will facilitate the early detection of emerging trends that may be climate-related. Surveillance can also be applied to established climate-sensitive risk factors (such as rainfall and surface water for mosquito populations and the production of pollen and spores in relation to asthma and other respiratory-tract allergies).
6. Forecasting of likely future changes in health risks
In conjunction with climate scientists able to generate location-specific scenarios of future climate change (temperature, rainfall, etc.), the health sector can provide regular forecasts of likely future risks to health. (For example, the ‘Climate Change and Health’ section of Canada’s federal health department has recently modelled how West Nile Fever and Lyme Disease are likely to spread in Canada over coming decades.)
7. Active engagement in inter-sectoral discussions and policy development
To achieve enduring reductions in vulnerability to the health risks of climate change, health-attuned policy development is needed on a broad sectoral front. Climate change impinges on whole populations, whole communities, and many of the health risks are linked to changes to physical, biological and ecological systems. The nature of many of the health hazards is such that ‘structural’ inter-sectoral policies are necessary.
8. Minimisation of greenhouse gas emissions by health system infrastructure
Hospitals, emergency transport systems, health-care technologies and disposable materials are potentially energy intensive. As for corporations and bureaucracies, the health-care system should exhibit best low-carbon practice.
Beyond the health sector, sustaining good health in the Australian population and all populations elsewhere requires the effective mitigation of global climate change. There is therefore an urgent need for the Australian Government to help forge an equitable, universal, targets-based and binding global agreement to achieve a phased and radical reduction in greenhouse gas emissions.