PRB Discuss Online: Does Climate Change Threaten Our Cities?

(October 2010) The cities and towns of developing countries are projected to absorb at least 2.5 billion additional people by 2050. At the same time, these areas will experience global climate change likely to bring floods, droughts, food insecurity, and loss of livelihoods. These converging trends pose mounting health risks for people living in urban areas in developing countries, especially for the poorest residents. Where are the greatest health risks and what can be done to manage them?


During a PRB Discuss Online, urban expert Mark Montgomery, Stony Brook University and the Population Council, answered participants’ questions about urban growth, health, and climate change.

Thanks to all who submitted questions. You can find additional information about this topic at:

Mark Montgomery, “Urban Poverty and Health in Developing Countries,” Population Bulletin (2009).

Climate Change and Urban Adaptation: Managing Unavoidable Health Risks in Developing Countries (Webcast, 2009).

The website for the Intergovernmental Panel on Climate Change (IPCC), which Professor Montgomery mentioned, is at


Oct. 30, 2009 1 PM EST


Transcript of Questions and Answers


Kenneth Lo: *What has to happen to the dynamics of urban development, especially in places where the majority of settlement is informal, such that “preparedness” can actually be incorporated into physical/social planning? *The impacts of climate change will be experienced differentially by various segments of urban population (i.e., the poor and disenfranchised). How might you frame the issue such that decision-makers align the interests of the poor and the wealthy? *What’s your take on climate change-induced migration (to/from/between cities)? *What are the priority social responses to consider for cities?
Mark Montgomery: You make an excellent point: Improving “preparedness” is precisely what governments at the municipal, regional, and national levels must focus on. The climate change scientists believe that extreme-weather events (hurricanes, flooding, storm surges, and the like) will take place more frequently and may well be more severe when they do occur. To prepare for these risks, governments will need to: (1) make overdue investments in the basic urban infrastructure, especially in the areas of drainage, sanitation, and water supply, that the poor neighborhoods of their cities have lacked; and (2) form new partnerships with NGOs and relief and disaster preparedness agencies (such as the Red Cross/Red Crescent, and establish better links among international, national and regional weather forecasting agencies) so that actors and systems are in place to anticipate climate change hazards and respond effectively when these hazards materialize. There is no inherent conflict between climate change adaptation in the cities of poor countries and the economic development agenda that has faced these cities. Much of what needs to be done in anticipation of climate risks has long needed to be done in any case. In many cities—especially coastal cities—there are important business assets that lie exposed to climate-related risks. There is at least a possibility that coalitions will form in which the interests of the business community and the urban poor will be aligned. That has not often happened in the past, but we may see it beginning to occur in the future.

Masoud Kheirabadi: Can Climate Change affect some cities positively? If yes, where? and how?
Mark Montgomery: Climate change is such a complex phenomenon, and is expressed so differently from one place to another even within a given country, that I am sure there will be some cities for which the changes will prove beneficial at least to a degree. (Think for example about cities in what have been ice-bound polar regions, where new shipping lanes may open up.) However, we need to recognize that the modern world is so inter-connected that changes in one place can have an influence on well-being in another place. At this point, knowing what we know today, it is awfully difficult to forecast what the net benefits might be for individual cities.

Megan Melamed: In addition to climate change causing floods, droughts, and food security issues on increasing populations in urban areas, air quality in urban cities is also expected to decline due to climate change exposing billions of people to high levels of air pollutants and causing millions of seaths. How come this is rarely mentioned as a consequence of climate change and what impacts it will have on billions of people?
Mark Montgomery: I agree with you that air quality is an under-appreciated factor in health. There is good agreement among the climate scientists that heat waves (magnified by the “urban heat island” effect) are likely to occur more often as climate change takes hold, and there is interesting research on the interactions between extreme heat and air pollution that makes the combination of the two more deadly. We are only beginning to see studies of cities in poor countries in which the joint effects of heat and pollution are examined—but I think more evidence is on the way.

Chinyere Fred-Adegbulugbe: I live i Lagos, coastal city in Nigeria. how exactly will climate change affect a city like Lagos and what can the government and other stakeholders do to avoid a possible disaster. 2, Many wealthy folks and estate developers are buying up reclaimed land on which they are building estates and mansions. Is this safe. what safety precautions can they take to prevent problems in the future
Mark Montgomery: I lived in Lagos myself and know exactly what you mean! There and elsewhere, it is very difficult for local governments in particular to prevent development from taking place in environmentally risky sites or in sites (such as mangrove swamps and wetlands) that serve as natural buffers in cases of storms and flooding. I would like to see a concerted effort made to thoroughly educate the Nigerian press about the local risks anticipated from climate change and highlight the kinds of unwise development that will exacerbate these risks in the future. Not every country has such a loud and vigorous press, and although publicizing problems is only a part of the solution, it is an important part.

Epokor Michael Kudjoe: Climate change is really a problem to deal with as it has great influence on health in our countries. Since cities are determined by population size it really goes on to affect the cities in the world especially the developing countries for that matter the sub Sahara countries with its high estimated growth. This is a problem, both natural and human factor contributed. Now how far can we go to curb its influence since there is no doubt that it really does threaten our cities?
Mark Montgomery: We often tend to think of city population growth in poor countries as being mainly caused by migration, but in fact the greater part of that growth is due to natural increase—the excess of urban births over deaths. And an important percentage of urban fertility is unwanted or unintended (according to the reports of the women who themselves had those births). Voluntary and effective urban family planning programs could reduce urban fertility in a humane and respectful way, and in so doing would (over the long term) cause city population growth rates to fall. Family planning is by no means *the* solution to the problems presented by climate change in poor countries, but we should think of it as another helpful tool in climate change adaptation, one that has a proven track record of effectiveness.

Adrienne Allison: The pace of climate change is accelerated by an ever rising tide of people living in cities and towns, using more resources, burning more fuel etc From the numbers, it is clear that population growth and climate change go hand in hand. Why aren’t we talking about slowing population growth whenever we atlk about climate change? Is population growth the “elephant in the lilving room”?
Mark Montgomery: There are at least two sides to the population growth question. For the most part, it is population and (more importantly) economic growth in rich countries that has produced the emissions that have resulted in global warming. Although population growth rates in rich countries are now generally quite low, it is possible that some climate-related benefits would ensue from further slowing of growth in these countries. But I doubt that the effects on future emissions would be very large. I would point you to the research on emissions by Brian O’Neill and colleagues for estimates of these effects. In poor countries, where urban and national population growth rates have been higher, slowing of population growth will reduce the costs of adaptation to climate change, by reducing the number of people likely to be exposed to climate-related risks. That is a long-term proposition, of course, but not one that we should ignore. As I mentioned in answering another question here, we need to give more attention to *voluntary* urban family planning programs. Those programs are well-justified on equity and reproductive health grounds alone; and their effects on future population growth are an additional justification.

Ellady Muyambi: Uganda is one of the countries projected to be affected by climate change if the current trend is maintained. Many people are moving from rural areas to urban areas and their final destination is usually slum areas. Yet, the government is not considering this as a problem. Eventually, drainage channels are always blocked due to poor waste disposal practices by these people. During periods of floods, these people suffer from diseases such as diarrhea, malaria, dysentry, cholera etc. What is your advice to the Ugandan government?
Mark Montgomery: Urbanization is a chaotic and messy process, but one that history teaches us is ultimately essential to economic development. As I’ve mentioned in response to other queries, migration is typically not as important to city population growth as is urban natural increase; but migration is too important to neglect. I would advise the Ugandan government to tackle directly the problems you’ve mentioned: improve drainage, unblock canals and storm sewers, reorganize collection of the solid wastes that currently clog these canals, and invest in better urban sanitation and water supply. These are all high-priority human development needs in any case, and climate change will only magnify their importance.

Purba Rudra: Apart from climate change directly affecting cities, in terms of some of its population being more vulnerable, how much of an impact do you think environmental migration will have on cities? Though the destination for environmental/climate change migrants isn’t necessarily the cities but a large number of them will end up in cities. How do you think will that impact the cities? Do yo think that will be a big issue in the future at all?
Mark Montgomery: There is a lot of discussion these days about environmental migrants, but not a lot of evidence on how many such migrants there are today, to say nothing of the future. Most migration that takes place in poor countries is from one rural place to another, and doubtless much of that is motivated by what you could describe as environmental factors, in the sense that one agricultural site may be preferred to another on the basis of local climate, soil quality, and the like. How much more of this movement will be produced by climate change is hard to say. Big numbers are being tossed around by some people, but the scientific basis for them is very slim. Even so, I think we should look closely at one large and especially fragile ecosystem—the drylands, where nearly 2 billion people live—and focus on the cities in this ecosystem, which account for about 45 percent of those 2 billion residents—as we consider the likely consequences of increasing water scarcities in the future. We might see rising costs of agricultural production in the rural parts of the drylands, which may in turn magnify seasonal, circular, and longer-term migration to dryland cities. The combination of rising agricultural prices and migration may put the labor markets of the urban poor under particular stress. I would keep an eye on situations like that. We demographers do not do a very good job in measuring migration, which leaves us essentially clueless where environmentally-induced migration is concerned, but I am hopeful that in the future much more emphasis will be placed on migration.

Dr. Pankaj Thapa: Climate change surely threatens our cities, and the worst sufferrers will be the urban poor. My question is what is the IPCC and other International organizations doing to save the vulnerable and economically deprived people living in the cities especially in Developing countries?
Mark Montgomery: Great question. The IPCC began to take the social and economic implications of climate change more seriously in the last Assessment, and it seems that even more attention will be paid to these issues in the next Assessment. The urban poor in low-income countries ought to and, I believe, will figure centrally in these deliberations. Stay tuned!

Tope Akintunde: I would like to know how you came about your projections on climate change in sub sahara africa. For instance the variables and the methodolgy used.
Mark Montgomery: The task of forming projections of climate change is being addressed by a very large group of climate and other geophysical and biological scientists. If you google “IPCC” you will be introduced to the research teams that have produced the forecasts, and will see what variables and methods they have employed. There is certainly much more that needs to be known about the forecasts for sub-Saharan Africa specifically, and the next stage of the scientific conversation should (and no doubt will) involve more criticism and refinement of the global models by those with detailed local knowledge of such environments. Africa’s geographers and physical scientists could make an enormously valuable contribution in connecting the global models to local realities.

Lanre Olusegun Ikuteyijo: With the prediction that the city of Lagos, Nigeria will be a mega-city in less that 10 years and as incessant flooding continues to belie the enviable achievements of the present administration in the state, What is your advice to the people and government of the state in order to avoid the consequences of climate change, in the face of the upsurge in population?
Mark Montgomery: My advice is to begin by (1) mapping in detail the poor neighborhoods of Lagos where flooding and other climate-related hazards already cause suffering and the loss of life and health. We know that flooding puts the young, women, and the elderly at special risk; and flooding is more damaging for the poor who live in homes too flimsy to withstand it. (2) These maps of vulnerability (which might be produced via the upcoming census) should then be placed in the hands of the decision-makers at the municipal, state, and national governments who will need to make decisions about infrastructure investments, especially in the areas of drainage, solid waste collection (which if uncollected tends to clog canals and other drainage systems), sanitation, and water supply. (3) The investment needs also should be made known to the African Development Bank and other international agencies with greater resources. (4) To prepare for a future in which flooding and other extreme-weather events are likely to occur more often and with greater severity, new partnerships will need to be formed with the NGOs and relief agencies that can assist local governments in preparing for and responding to disasters.

Nidhi Mittal: 1. How do you see the role of urban agriculture in mitigating the impact of climate change and enhancing food security in urban cities? 2. Will mitigating rural to urban migration at source be a possible solution for urban world issues?
Mark Montgomery: Urban agriculture is already important in giving some city residents a measure of food security, insulating them to a degree from market-induced variation in food prices. Development of green spaces within cities will be one of the strategies that can ease “urban heat island” effects and thereby affect one important aspect of urban health. In some cases, at least, development of urban agriculture could be compatible with the development of green spaces. But I will defer to the experts on urban agriculture (I am not one of them) for more on this point. On migration, there is little evidence that movement can in fact be stopped “at the source” (apart from special cases such as China pre-1980) and more importantly, no good reason for doing so. People move in search of better standards of living and a better life in general, and to deny rural residents access to the city is to deny them that opportunity for betterment. Naturally, flows of in-migrants do complicate the task of urban management and governance, but we should put our emphasis on improving management and governance and encouraging growth of a system of cities, not on trying to prevent migration, which is a futile exercise in any case. There’s much talk these days about the role that international remittances play in national development, but we seem to have lost sight of the (presumably much larger) role played by urban-to-rural remittances and other economic benefits that internal migration brings for rural residents and rural areas. Fostering rural-urban connections is part of good economic development strategy. The 2009 World Development Report of the World Bank made this case very well, I think.

Ujah Oliver Chinedu: Dear Mark, to what extent do you think climate change threats provides an opportunity for the development of sustainable cities in sub-Saharan Africa?
Mark Montgomery: I would agree with you that climate change does present positive opportunities—the urban adaptation agenda will involve making investments in drainage, waste collection, and so on to safeguard the slums and other city neighborhoods that already live with climate-related environmental threats. These vulnerable areas have not received the infrastructure they need—but I am hopeful that as climate change seizes the attention of policy-makers, they will at last view the environments of the urban poor as deserving of urgent attention.

Ujah Oliver Chinedu: Second question Mark, are there funds available (at the global level) for studying the impact of climate change in developing countries’cities?
Mark Montgomery: Funds are beginning to be available for exactly this sort of research. Good urban climate adaptation research will require real partnerships to be formed between global researchers and local experts. In particular, sub-Saharan Africa has long had an unusually strong community of geographic researchers in and outside its universities; their talents will need to be tapped. There is also good physical science expertise in the region that will need to be joined to good social science—climate change research needs a healthy dose of both kinds of science.

Sarath Guttikunda: Cities will be affected by Climate Change, but they are more threatened by the more current problems, such as air pollution, which has same roots as climate change, the fossil fuel burning, with immediate impacts of human health. When talking about cities, why is this side lined?
Mark Montgomery: Another person in our discussion also raised the issue of urban air pollution, which I agree is an under-studied aspect of urban health. There are some excellent research reviews available. I am beginning to see research on air pollution in developing-country cities—Wuhan (China’s “oven city”), Shanghai, and New Delhi come to mind in addition to Mexico City and other Latin American cities (which have a rich tradition of scientific studies).

Kebede Kassa: How can developed countries help developing countries address the issue of urban solid and liquid waste which contributes to global warming and climate change?
Mark Montgomery: I would put this question differently. Some of the most important *consequences* of global climate change will be expressed in terms of more frequent and more severe extreme-weather events, especially flooding, storm surges, and the like. Poor (or non-existent) systems of urban solid waste collection cause drainage canals and other outlets to become clogged, which makes flooding worse. On these grounds alone there is a need for more attention to urban waste collection.

roger-Mark De Souza: Could you address the issues surrounding climate change (sea level rise), urbanization, and coastal cities in small island developing states such as the Caribbean? What do you see as program and policy options for such islands?
Mark Montgomery: The recent “underwater cabinet” meeting in the Maldives effectively drew attention to the most threatened of the small island states. Fortunately, the situation facing the Caribbean island states is not (currently) forecast to be quite that dire. In this region, there is still much to be done to safeguard the neighborhoods of the urban poor from the threats of flooding and (in some cases) landslides. There will inevitably be cases in which some communities of the poor, living in highly threatened environments, will need to relocate. But relocation can be accomplished humanely, with full attention to the needs of the poor. In the wonderful journal Environment and Urbanization, one can find multiple case studies in which poor communities and governments functioned as partners in finding relocation solutions. I highly recommend the accounts in that journal, which would be instructive for the Caribbean as well.

Dr. Anima Sharma: Climate change is a global phenomenon. The reasons are various and most of those are created by Man. But, unfortunately none of the man made efforts are globally effective. The damages have already been done now we can only think about the remedial or palliative treatment. My question is that if we stop even now and check the further depletion of the environment then how long will it take to improve the damages already done? Are those damages controllable and reversible or are those beyond our capacity and irreversible?
Mark Montgomery: I am an economist and demographer, and therefore not well equipped to address the physical sciences issues of irreversibility that you raise. But as I understand it, there is a broad general consensus that where climate change is concerned, we cannot afford to ignore either mitigation (reducing emissions) or adaptation (dealing effectively with the consequences).

Kenneth Lo: Re: your response to Fred-Adegbulugbe, can you cite any good examples of governments at any level or NGOs working on preserving/restoring ecological infrastructure (buffer zones, mangrove forests, etc.) specifically with mitigation in mind?
Mark Montgomery: If by mitigation, you mean with the aim of reducing emissions, then I would suggest googling the 2009 Urban Research Symposium (a World Bank conference held in Marseille at the end of June) where a number of case studies on this general theme were presented. I recall seeing several Latin American cases, but do not at the moment have the details for you.

Tim Mock: As the stresses of the climate crisis increase, human violence is expected to increase (See “Climate Wars” by Gwynne Dyer for one geopolitcal analysts viewpoint.). Do you expect the violence to be worse in urban or rural settings?
Mark Montgomery: Since violence is a symptom of a more fundamental failure of governance, it is difficult to foresee whether climate change as such will result in greater violence in either urban or rural areas. Surely this depends on how governments and civil society respond and adapt to the climate change challenges. But I would direct you to the recent National Intelligence assessment carried out by the U.S. government for the thoughts of security experts on these matters. There is concern expressed about the possible consequences in dryland regions, where water scarcities are already a big issue and where it seems likely that climate change might intensify the competition over scarce agricultural resources.

Kenneth Lo: The references indicate you’ve studied small and medium-sized cities as a critical and overlooked category of urbanization in developing countries. What are the challenges specific to these cities and towns, with respect to climate change and to urban health in general?
Mark Montgomery: The needs of small and medium-sized cities are typically overlooked—but this is where (collectively) the vast majority of urban residents actually live, and these smaller places are generally short of technical expertise and managerial talents that would help them address needs in health and climate change. For instance, we hear a great deal about urban-rural imbalances in the distribution of public health personnel; but we hear much less about similar imbalances between large and smaller cities. Also, governments are decentralizing in many poor countries, and smaller cities typically lack the independent resource base and taxation systems that would allow them to sustain themselves in the absence of well-designed inter-governmental transfers. The shortages of resources that usually afflict small cities and towns are plainly evident in the levels of health in these places (with risks not unlike those of rural villages) and levels of poverty.

Kenneth Lo: How does the lack of robust governments/structures in these small and medium-sized cities impact your work as a demographer? What efforts exist to ensure that both attention and resources are committed to these populations? Any good models? Thanks!
Mark Montgomery: In general, we know very little about small and medium sized cities, which don’t figure (by name) in the nationally-representative surveys by which we learn about demography, health, and the like. But in Latin America, several countries are making a concerted effort to get *census* data disaggregated and mapped for these smaller places, and that effort ought to be on the priority list for national statistical offices around the world. For climate change, health, and economic development in general, we need quantitative portraits of these smaller places, and usually it is only via censuses that we can get such portraits.