Harnessing urbanisation for human wellbeing and planetary health

Abstract

Urbanisation is a planetary scale change process. In the past 200 years, the proportion of the world's population living in cities has grown from about 5% to more than 50%.1McMichael AJ The urban environment and health in a world of increasing globalization: issues for developing countries.Bull World Health Organ. 2000; 78: 1117-1126PubMed Google Scholar By 2050, about 2·5 billion additional people will need to be housed in cities—more than 1 million people every week—with about 90% of the increase concentrated in Asia and Africa.2United NationsDepartment of Economic and Social AffairsPopulation DivisionWorld urbanization prospects: the 2015 revision. United Nations, New York2015https://esa.un.org/unpd/wpp/Google Scholar Urban land cover is expected to increase by more than 1 million km2 by 2030, nearly tripling the global urban land area circa 2000, threatening biodiversity and affecting ecosystem productivity through loss of habitat, biomass, and carbon storage.3Seto KC Güneralpa B Hutyra LR Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools.PNAS. 2012; 109: 16083-16088Crossref PubMed Scopus (2311) Google Scholar Urban ways of living are the keystone of modern human ecology.1McMichael AJ The urban environment and health in a world of increasing globalization: issues for developing countries.Bull World Health Organ. 2000; 78: 1117-1126PubMed Google Scholar Having evolved as hunter gatherers living in natural environments with ready access to a healthy diet and plenty of opportunity for physical activity in daily living, most Homo sapiens in the world are now living with a mismatch between their evolutionary biology and their environment.4Gluckman P Hason M Mismatch: The lifestyle diseases timebomb. Oxford University Press, Oxford2008Google Scholar Although, on average, the health of urban dwellers is better than rural dwellers, urban health inequities have been well documented.5Kjellstrom T Friel S Dixon J et al.Urban environmental health hazards and health equity.J Urban Health. 2007; 84: s86-s97Crossref PubMed Scopus (117) Google Scholar Associations between health and location have been studied since at least the time of Hippocrates. In ancient Roman civilisation, aqueducts brought clean water into the cities. Swamps were drained. With the dawn of the Anthropocene, rapid industrialisation and urbanisation in places such as England began to affect the health of urban residents, particularly those living in crowded and unsanitary conditions. Sir Edwin Chadwick and others successfully argued for urban reforms in the interest of public health. The contemporary discourse of urban health has mostly focused on the social determinants of health. Although the original ambition of the WHO Healthy Cities programme encompassed concern about the health of ecosystems,6Hancock T The evolution, impact and significance of the health cities/healthy communities movement.J Public Health Policy. 1993; 14: 5-18Crossref PubMed Scopus (97) Google Scholar in practice less attention was given to ecological foundations of health in most healthy city projects. In parallel, urban planning, transport, and engineering leaders have advanced a discourse on sustainable cities that, on the whole, has paid less attention to the human and social dimensions of sustainable development. It is essential to transcend these two separate discourses and take a more interdisciplinary, and integrative, approach to sustainable urban development.7UNU-IIGHPeople, planet and participation: the Kuching statement on healthy, just and sustainable urban development.Health Promot Intl. 2016; (published online June 26.)https://doi.org/10.1093/heapro/daw046Crossref Scopus (5) Google Scholar Concern about the human health impacts of toxic urban air pollution has fuelled a resurgence of global interest in the links between urbanisation and health. With almost 1 billion people living in slum households, a pressing need exists for action to address their high risks of infection and injury.8Ezeh A Oyebode O Satterthwaite D et al.The history, geography, and sociology of slums and the health problems of people who live in slums.Lancet. 2017; 389: 547-558Summary Full Text Full Text PDF PubMed Scopus (301) Google Scholar The large urban populations in river deltas of Asia are particularly vulnerable to inundation during extreme weather events.9Nicholls RJ Wong PP Burkett VR et al.Coastal systems and low-lying areas. Climate change 2007: impacts, adaptation and vulnerability.in: Parry ML Canziani OF Palutikof JP Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge2007Google Scholar In this rapidly evolving context, the Sustainable Development Goals include a specific urban goal—Goal 11: Make cities inclusive, safe, resilient, and sustainable. In October, 2016, the UN convened Habitat III, its third conference on housing and sustainable urban development. The goals and ambitions have been set. The challenge is implementation. Because cities are now the dominant human habitat, it is essential for health that they are fit for purpose. Cities are for people10Gehl J Cities for People. Island Press, Washington, DC2010Google Scholar and therefore human health, wellbeing, safety, security, and opportunity should be central considerations in sustainable urban development. All people share a set of universal health needs (panel)11Boyden S The Biology of civilisation: understanding human culture as a force in nature. University of New South Wales Press, Sydney2004Google Scholar and the ambition of urban governance should be to meet these needs in sustainable ways.PanelUniversal health needs of the human speciesBiophysical needs•Clean air•Clean water•A natural diet•Absence of harmful levels of radiation•A natural microbiome•Protection from extremes of climate•A natural amount of physical activity•SleepPsychosocial needs•An emotional support network•The experience of conviviality•Opportunities for co-operation•A natural level of sensory stimulation•An interesting environment•An aesthetically pleasing environment•Opportunities for creative behaviour•Opportunities for learning•Opportunities for recreation•Opportunities for spontaneity•Variety in daily experience•Absence of alienation and deprivation•A sense of belonging, purpose, and love*Adapted with permission from Boyden.11Boyden S The Biology of civilisation: understanding human culture as a force in nature. University of New South Wales Press, Sydney2004Google Scholar Biophysical needs •Clean air•Clean water•A natural diet•Absence of harmful levels of radiation•A natural microbiome•Protection from extremes of climate•A natural amount of physical activity•Sleep Psychosocial needs •An emotional support network•The experience of conviviality•Opportunities for co-operation•A natural level of sensory stimulation•An interesting environment•An aesthetically pleasing environment•Opportunities for creative behaviour•Opportunities for learning•Opportunities for recreation•Opportunities for spontaneity•Variety in daily experience•Absence of alienation and deprivation•A sense of belonging, purpose, and love *Adapted with permission from Boyden.11Boyden S The Biology of civilisation: understanding human culture as a force in nature. University of New South Wales Press, Sydney2004Google Scholar Context is important. No single model exists for sustainable and healthy urban development. Cities, rightly, should reflect their unique geographies, histories, economies, politics, and cultures. The discipline of human ecology is useful in understanding urban health challenges and thinking through solutions. Systems thinking can help bring expertise from different disciplines together with local knowledge for effective urban governance. Importantly, urban development is a political process and addressing the maladaptive political economy at play in many cities is fundamental to planetary health. Although more empirical research is doubtless needed, particularly in low-income and middle-income countries, action is required on what is already known. The recent Lancet series on the health of people who live in slums8Ezeh A Oyebode O Satterthwaite D et al.The history, geography, and sociology of slums and the health problems of people who live in slums.Lancet. 2017; 389: 547-558Summary Full Text Full Text PDF PubMed Scopus (301) Google Scholar and urban design, transport, and health12Giles-Corti B Vernez-Moudon A Reis R et al.City planning and population health: a global challenge.Lancet. 2016; 388: 2912-2924Summary Full Text Full Text PDF PubMed Scopus (596) Google Scholar provide up to date policy research syntheses on key themes. Traditional knowledge can also be useful—for example, the experience of urban populations in North Africa dealing with extreme heat over millennia without air conditioning provides lessons for climate change adaptation in other regions. In 1992, the Secretary-General of the UN conference on environment and development declared that if our planet is to remain a hospitable and sustainable home for the human species, the battle would be won or lost in major urban areas. Much work remains to be done. In the interest of the wellbeing of current and future generations, we must re-think our current approach to urban development and governance to enable all people to flourish on our precious planet Earth. I declare no competing interests.