Climate change is likely to seriously affect the health of urban Asians. Most at risk are those who live in hazard zones – flood plains, coastal areas and on unstable hillsides. Improved understanding of the local and current impacts of climate variability is vital to reduce the impacts of climate change in the future.

A paper from the London School of Hygiene and Tropical Medicine, in the UK, and Jawaharlal Nehru University, in India, reviews scientific evidence for the effects of temperature, rainfall and extreme weather events on human health, in particular the impacts of heat waves and floods. The authors show that the ill-effects of global warming will predominantly affect populations who have contributed little to greenhouse gas emissions.

Cities alter their local climate by reducing rainfall and increasing night time temperatures, at times by as much as 10 degrees Celsius. The ‘urban heat island’ effect is caused by daytime heat being retained by the fabric of buildings and by a reduction in cooling vegetation. High urban temperatures not only affect health but are also an important occupational health hazard and reduce productivity. European policymakers are exploring how to prevent deaths during heatwaves but the issue of how to manage urban heatwaves – often worsened by increased humidity and air pollution – has not yet become a general public health concern in Asia.

Human health in temperate and tropical Asia will be endangered by:

• increased rainfall intensity, particularly during the summer monsoon
• more frequent outbreaks of water-borne disease: there is mounting evidence of how extreme rainfall can lead to sharp increases in diarrhoeal disease and leptospirosis, particularly in informal settlements
• decline in available water as glacier melt declines, rivers become seasonal and rising sea levels increase saltwater intrusion into aquifers.

Sectoral approaches to climate change impact assessments often ignore the effects on health. Risks to health from extreme weather events need to be described better, and public health interventions need to be improved. Improving the resilience of cities to climate change requires improvements in drains, water pipelines and other urban infrastructure. However, as the climate changes, these improvements are unlikely to be achieved quickly enough to avoid an increased burden of disease.

The United Nations Framework Convention on Climate Change has prompted several developing countries to develop National Adaptation Programmes of Action. However, few of these address health issues. Echoing the World Bank, the authors call for:

• comprehensive assessments of health risk vulnerabilities for exposed cities and wider dissemination of information: assessments should be based on both optimistic and pessimistic assumptions
• establishment of early warning and evacuation plans, including emergency preparedness and neighbourhood response systems
• more efficient water supply management
• increased institutional capacity in urban environment management
• property rights for people living in informal settlements and other measures to allow low-income groups to buy, rent or build quality housing on safe sites.

Source(s):
‘Climate, climate change and human health in Asian cities’, International Institute for Environment and Development, Environment and Urbanization; 20; 165, pp 165-175, by Sari Kovats and Rais Akhtar, 2008 Full document.

id21 Research Highlight: 13 August 2008

Further Information:
Sari Kovats
Centre on Global Change and Health
London School of Hygiene and Tropical Medicine
Keppel Street
London WC1E 7HT
UK

Tel: +44 20 79272962
Fax: +44 20 74365389
Contact the contributor: sari.kovats@lshtm.ac.uk

Centre on Global Change and Health, London School of Hygiene and Tropical Medicine, UK

Rais Akhtar
Centre for the Study of Regional Development
Jawaharlal Nehru University
New Delhi 110067
India

Tel: +91 11 26742676
Fax: +91 11 26742580
Contact the contributor: raisakhtar@hotmail.com

Centre for the Study of Regional Development, Jawaharlal Nehru University, India

Other related links:
'From knowledge to action: dealing with climate change in Asia'

'Managing droughts instead of floods in Viet Nam'

'Severe urban health disparities to increase with climate change'

'Climate change and cities', Issue #71, January 2008, id21 insights