Climate Change and Healthy Communities

05-Dec-11

Health and Climate Change

There are three dimensions to consider:

The health consequences of climate change
Health benefits from reducing emissions
Health benefits from adaptation measures

The measures directed towards reducing greenhouse gas emissions and adaptation to the consequences of climate change are strongly linked with public health.

Health consequences of climate change

The health outcomes from climate change are complex as the effects occur at different spatial scales, over 20-100 year timescales and impact upon complex environmental and social systems that ultimately influence public health. Key aspects of uncertainty surround how financial, legislative, cultural and other measures modify community behaviour and thus the risks to public health.

These measures are not only evident at the level of the individual in terms of personal decisions made to walk or cycle, but also at the community level. It is at the community level where planners and designers not only influence the likelihood of changed individual behaviour, but also providing and urban fabric that reduces exposure to the adverse effects of climate change.

The consequences of climate change on health are associated with the following components of change:

Temperatures

After 2030 heat waves similar to that of 2003 will be more frequent. Heat related deaths begin to occur when the mean daily temperature rises above the minimum mortality band of 15.6-18.6 degrees C. An estimated 800 heat-related deaths occur per year, with increased levels of hospital visits.

With higher temperatures more deaths, particularly among the elderly, are likely; however, winter deaths will become less common. The effects are not equally spread across the country; for example, the South East and West Midlands experienced the greatest excess mortality during the July 2006 heatwave (Department of Health, 2009: Heatwave Plan for England). A 10% increase in the rate of food poisoning is expected by 2050. The population will also adapt to warmer conditions.

Risk factors for heat stress

Being over 80 years old
Being bedridden
Use of drugs
Cardiovascular illnesses
Neurological ailments
Mental conditions
Endocrine disorders
Skin disorders
Infections

The NHS has reacted with a plan to protect health and reducing harm from heat waves.

Sea level rise, rainfall and flooding

Decreasing summer rainfall and increased frequency of heavy precipitation is forecast by Defra to place 80,000 urban properties at risk from flash flooding. Autumn and winter flooding is judged to be more frequent. The displacement of people from homes contributes to increased stress and suicides. A health risk is also associated with living in damp properties.

Wind speed

Increased wind speed causes building damage and falling trees. While high speeds are unlikely to cause damage to most buildings, the hazard to pedestrians can be greatest where the corners of high-rise buildings abut large open areas. Loss of electricity may contribute to accidents and put at risk those dependent upon medical electrical equipment.

Water quality

Climate change will affect the relationship between water quality, disease vectors and health. Potential effects include: increased surface water turbidity, changes in vector breeding patterns, increased pathogen survival, legionella risks, algal blooms, increased leisure exposure to water related risks and breaching of water treatment and waste water treatment works.

Ecological systems

These systems are affected by climate change not only causing change with direct or indirect health effects but also increased risk of fires across habitats and an extended season for allergens.

Reducing emissions

Measures directed toward reducing emissions are associated with avoiding the use of carbon-based energy or by using it more efficiently. Applying this approach to the housing sector can give rise to health benefits by improving energy conservation, particularly for low income and elderly groups. This reduces the numbers in fuel poverty and it is known that housing conditions are a key influence on the health of the elderly or those with respiratory ailments.

In terms of transport, efforts directed towards reducing the need to use motorised transport also promote improved physical fitness with consequential benefits for obesity and diabetes. It also leads to enhancement of the physical environment, due to attempts to make walking and cycling more attractive. Evidence links a relationship between the attractiveness of the environment, particularly the amount of vegetation and wildlife, with reduced levels of stress and improved rates of recovery from illness.

Adaptation

The value of parks and opens spaces not only in the provision of cooling areas, but in terms of the opportunities afforded for physical exercise and also to enjoy relative tranquillity, should be recognised and expanded.

Trees are key to changing local microclimates by creating shade, allowing cooler air to circulate and to reduce air temperatures by transpiration. Trees also extract pollutants (generated by traffic) and carbon dioxide. A green environment also contributes to health, with evidence suggesting that people recover from illness more rapidly, are more likely to take physical exercise and have reduced levels of stress.

Planners and urban designers need to deliver changes to the urban infrastructure so that buildings stay cool in hot weather, warm in winter and are flood-resilient. Energy efficiency, reducing the need to use motorised transport and appropriate spatial planning are all essential measures contributing adaptation and health benefits.