Climate change, health and urban resilience are all connected, and this means research and policy in these arenas must join up.
Why are the health prospects for residents in informal urban settlements so poor, and what future issues will contribute to making these better or worse? These were among the questions discussed at the 11th International Conference on Urban Health held recently in Manchester.
As part of this event, a group of participants grappled with the ways in which climate change will affect urban health, based on experiences of both the threats and opportunities of managing health risks in countries including India, Tanzania and Vietnam.
Look at all the factors
Efforts to identify the health consequences of climate change have often adopted an 'impacts-first' perspective, identifying pathways through which particular changes in (for instance) temperature or rainfall patterns will affect individuals.
But this does not tell the full story. People exposed to high temperatures or disease pathogens will be affected in different ways, depending on their age, their pre-existing health, their work, the quality of their housing and many other factors.
Public health experts rightly identify both social and ecological factors as being important determinants of health. This awareness is central to understanding people's vulnerability to climate change — which is shaped by exposure to particular shocks and stresses, their likelihood to be harmed as a result of these, and the extent of their capacity to adapt to reduce the harm they experience in future.
In this sense, approaches to improving urban health and to reducing harm from climate change in urban areas can be aligned effectively — through strengthening the underlying resilience of individuals and communities to health risks and other threats, and through addressing many of the underlying environmental health threats associated with poor sanitation and inadequate basic services.
India and Tanzania
Surat, a city of 4.5 million people in India, has a history of disease outbreaks — including plague epidemics following extensive flooding in 1994 and 2003. The city's susceptibility to flooding, combined with the large number of low-paid migrant workers living in poor conditions, came together to result in the rapid spread of disease.
But these disasters spurred significant improvements to the public health system, and the city is also showing signs of resilience — public health officials and NGOs have developed more effective health surveillance systems that have been able to reduce the time taken to identify epidemics from 10-15 days to 1-2 days.
But perhaps the more significant effects of climate change on human health will be on the ways that gradual changes in the physical environment will influence the spread and consequences of communicable disease.
Preliminary estimates presented at the conference suggest that in Dar es Salaam more than 9,000 people die each year from HIV/AIDS/TB related illnesses, more than 5,000 from pneumonia and influenza, and around 3,500 each from malaria and diarrhoeal diseases. These figures dwarf the numbers who die as a direct result of disasters.
They suggest that ways in which changes in the climate will affect the quality of drinking water or the rate at which communicable diseases spread are likely to have a more significant effect on patterns of illness and death than changes in the frequency of occasional extreme events.
Systems approaches to resilience
The limits of using uni-directional pathways to understand influences on human health are increasingly recognized by medical experts too – as they have begun to realize the value of systems approaches that take multiple factors into account.
This type of approach has been adopted in some urban responses to climate change that stress the importance of strengthening urban systems (including protective infrastructure and basic service provision), agents (including individuals and community organisations) and institutions (including the governance frameworks that set city priorities) to build resilience.
Systems approaches highlight the interconnectedness of a range of different factors, and avoid the pitfalls of reductionist methods that try to link single causes with single effects. Resilience thinking for urban centres also highlights the importance of learning — by individuals and institutions — as a key means of reducing future risk.
The case of Surat clearly shows how different organizations in the city have learned from past failures in preventing the spread of disease, and have used these as the basis for developing more appropriate future responses.
Learning from the experts
Organised groups of low-income urban residents are already showing ways in which local responses can help to reduce risks to human health and build climate resilience — while addressing many of the present-day development needs that they face.
Members of the National Slum Dwellers Federation in Uganda are using innovative building materials to construct homes at low cost that improve both the social and environmental conditions of their inhabitants (see photo). Interlocking compressed earth blocks with hollow centres improve the insulation of buildings, and keep them cooler when temperatures are high — and at the same time do not need to be baked in wood-fired furnaces, thus reducing the need for cutting down trees for firewood.
They have also introduced rainwater harvesting systems in community toilet blocks — reducing reliance on piped water at the same time as improving sanitation facilities.
These activities point towards ways in which several inter-related and critical urban needs can be addressed. The health of low-income urban residents and the effects of climate change on this cannot be dealt with in isolation of the broader needs that these groups face.
New international efforts — including the creation of the post-2015 sustainable development goals and the development of a new climate change agreement at COP21 next year — should take their inspiration from groups such as these if they're to help other vulnerable individuals and communities in the future.
David Dodman is a senior researcher in IIED's human settlements group (firstname.lastname@example.org). The project is funded by UK aid from the UK Government, however the views expressed do not necessarily reflect the views of the UK Government.