A human floodtide

Migration issues are causing consternation for many governments, including in the developed ‘North’ where the comparatively greater economic opportunity and socio-political stability is seen to operate as a significant ‘pull.’ Imagine this combined with an enormous increase in the ‘push’ from developing countries due to climate change and attendant repercussions.

While migration has always been a survival strategy for humans, presently unprecedented numbers of people from the developing world are seeing migration as the favoured option to environmental, political, and economic problems and discontents.

 The Intergovernmental Panel on Climate Change (IPCC) notes that human migration may be one of the greatest outcomes of climate change. While estimates vary, the initial number of 150 million environmental refugees resulting from global warming by the end of the 21st century has been revised upwards, with the IPCC noting that by the middle of the century over 200 million people could be forced from their homes and land, with many more succumbing to malnutrition and heat stress.

Weather-related disasters, together with the flooding of low-lying, heavily populated areas due to rising sea levels, are perhaps the most obvious and direct ‘push’ related to climate change.

Most migrants would likely move away from economic problems brought on by disrupted livelihoods operating very close to the land. Such livelihoods depend heavily on seasonality, agronomic resources, and local food and water availability.

Thus there are essentially two broad categories of environmental migrant due to climate change: those directly and forcibly dislocated due to sea level rise and weather events, and those whose livelihoods are reduced in viability such that they seek opportunity and stability elsewhere.

The numbers of people forced to migrate due to sea level rise is the more easily calculated category, due to the comparative ease with which populations attached to coastal elevations can be counted.

It is estimated that roughly one billion people will be at risk of displacement due to the rise in sea level of approximately one metre expected by 2080.

The areas of greatest impact are the tropics and warm temperate regions, where the coasts are heavily settled and the poor make up a large percentage of the population. The most susceptible areas include the southern coast of the Mediterranean, the west coast of Africa, south and southeast Asia, and the inhabited islands in the Pacific and Indian Oceans.

These areas comprise some of the most heavily populated and poorest countries in the world, with some of the highest population growth rates.

In West Africa and Egypt over 5.5m hectares would be inundated, displacing about 15.2 million people. On the east coast of Latin America a one metre rise would flood around 13.5m hectares and affect 750,000 people.

The majority of ‘sea-level rise migrants’, however, will come from China and Southeast Asia, which constitute the most densely populated coastlines in the world (see map). In Southeast Asia over 10.2m hectares will be inundated by a one metre rise in sea level, forcibly displacing over 45 million people.

But estimates of such a large and complex phenomenon vary. A separate ‘worst case’ scenario has China experiencing some 72 million people displaced, and Bangladesh 71 million. Still another puts the global displacement due to sea level rise at 100 million per year by 2080. But whatever estimate is used, believed to be precise or imprecise, or even cut in half or by two-thirds, they are all large numbers and have substantial repercussions.

The other category of climate-induced migrant, those whose livelihoods are disrupted due to indirect effects, is much more difficult to calculate for a variety of reasons. Among the calculation difficulties is the relative vulnerability of the populations concerned.

High vulnerability (in other words a low ability to cope with livelihood shocks — the poor) means that a relatively small impact or disruption can have a much larger effect than it would among rich populations who are not as vulnerable. Sufficiently detailed global digital maps of elevation, crops, population, and livelihood vulnerability do not exist.

Then there is the issue of ‘snowballing’ effects due to multiple, interlinked factors, such as climate impacts plus political, economic, or social situations which combine to dislocate people. The indirect effects are the result of numerous and shifting causation, constituting a complex series of interactions which result in decisions to migrate. As a result, it can be difficult to distinguish a singular cause of migration from the environmental, economic, and political mix.

The more important indirect dislocating effects focus on agriculture, which is particularly vulnerable to weather and climate change. These include multi-year drought, changes in seasonality, reductions in cultivated areas due to land degradation, land scarcities, and declines in agricultural and economic productivity with resulting food supply problems.

 Large-scale migration itself has an impact on receiving countries and communities, leading to scarcities in employment, water, land and food. This is sometimes followed by the decision by local inhabitants to go elsewhere, creating a domino effect. Countries close to the equator are expected to be particularly hard hit in terms of declining crop yields, leaving hundreds of millions of people without food security.

While harvests may initially increase in temperate countries due to longer growing seasons, they are likely to fall by 30 per cent in India, affecting 130 million people by the 2050s. The IPCC indicates that in Africa declining yields could result in hundreds of millions of people unable to grow food. Global crop yields will likely be affected as almost one third of the earth’s surface could be at risk of extreme drought by 2099.

Shortfalls in freshwater due to climate change will contribute further to out-migration. It is estimated that in 20 years time tens of millions of Latin Americans and hundreds of millions of Africans will face water shortages, and by 2050 one billion Asians could be short of water. The Himalayan glaciers, which feed the large Asian rivers, are likely to be substantially gone by 2035, impacting on the lives of some 700 million people.

The map here illustrates a couple of issues. First is the geography of the two categories of migrants. The largest number of coastal mega-cities are in Asia, which also has the largest and fastest-growing population of urban slum-dwellers. These constitute the bulk of those who will be threatened with sea level rise in the future.

Second, migrants dislocated due to indirect compounding effects are presently in Africa, Eastern Europe, parts of Central Asia, and the Middle East. Thus the two categories of climate change migrants occupy roughly different parts of the globe, hence the pervasiveness of the overall climate change-migrant problem.

 Where will the migrants go? While the developed nations will continue to be targets for migrants escaping the ravages of climate change, and the concern is justified, the reality is that an overwhelming majority of migration takes place internally, within national boundaries. Internally displaced persons constitute roughly half to two-thirds of displaced populations. Internationally, most migrations occur between countries of the ‘South’. Fifty per cent of the world’s displaced persons are found in Africa alone. This places primary concern on the nations of the developing world who are least able to cope.

The swelling Third World cities are the primary migrant destination, and will constitute a compounding set of problems with significant political repercussions. Most migration occurs from rural areas to urban areas within or between developing countries. The world’s urban population is expected to more than double by 2025, to over five billion, with 90 per cent of this increase to occur in the developing world.

Some of the largest cities in the developing world are coastal (map), and hence subject to sea level rise. Of the world’s 20 mega-cities, 15 lie on or near a coast. The land underneath many coastal cities is sinking due to excessive groundwater pumping and urban sprawl, which deflects rainwater infiltration away from aquifers.

This makes such cities very vulnerable to saltwater intrusion. Aquifer saltwater flooding is currently a serous problem for Bangkok, Jakarta, Manila, Dhaka and other cities. The problem will be compounded since rates of subsidence may exceed that of sea level rise between now and 2100. Such a looming lack of freshwater for growing urban populations will be a significant financial and political consideration, and can cause subsequent migrations.

These population concentrations, coupled with scarcities of the basics, are particularly risky as sources of conflict or aggravation of conflict. The UN Secretary General, Ban Ki-moon, has indicated that ‘[in] coming decades, changes in the environment — and the resulting upheavals, from droughts to inundated coastal areas — are likely to become a major driver of war and conflict.’

Margaret Beckett, the Foreign Secretary has called climate change ‘a security issue’, and a US Pentagon report has concluded that ‘skirmishes, battles, and even war due to resource constraints’ could ensue due to climate change. Indeed, the prospect of ‘water wars,’ particularly where rivers or aquifers are shared by more than one country, is thought to be a primary security issue in the near future.

Sixty-one nations, primarily in the Third World, are at risk of increased levels of conflict due to concentrating populations coupled with climate change. Of these eight are countries that contain significantly large populations: Nigeria, Russia, Bangladesh, Egypt, India, Indonesia, Turkey, and South Africa; 24 will experience disruptions due to problems in crop production, five from disease, 14 from issues tied to deforestation, 16 due to sea level rise, 31 countries are in Africa, and six countries express significant anti-Western sentiment: Iran, Iraq, Sudan, Somalia, Yemen, and Libya. And again the refugee concentration in the Middle East is considerable (see map).

The security aspect is of particular concern given the general recognition that the character of current instability often comprises low intensity conflict within nations, rather than between them. Their origins are buried deep within aggravating problems of inequitable access to resources, in particular land resources.

The UK’s recent highlighting, to some consternation, of climate change and its repercussions as a security threat in recent UN Security Council debate emphasised both the potential security risks that some nations are sensitive to, and the utility of the issue politically.

Ugandan president Museveni has claimed that global warming is an ‘act of aggression by the rich against the poor.’ Ambassador Robert Guba Aisi of Papua New Guinea argued that ‘the dangers that the small island states and their populations face are no less serious than those nations threatened by guns and bombs.’ Other developing countries have similar perspectives.

Increased health risks are another primary concern. The growth of multi-million inhabitant cities in the Third World along with ecological change are already expanding the reach of infectious diseases. As the environment changes and allows for greater ecological occupation of disease vectors, so too will migration act to spread disease.

When migrants arrive in developed countries, the perception of the accompanying health threats (real or imagined) is likely to have a political and policy impact. Most countries currently have health requirements for arriving migrants, tourists, and guest workers; they bar entry to those known to be, or suspected of, carrying certain diseases. Migration is known to be a primary form of the spread of AIDS, for example.

Many developed and developing countries contend that the increased flow of migrants is already becoming a burden that must be dealt with using a ‘closed-door’ policy approach. With reduced opportunities for entering countries legally, many migrants will attempt to enter illegally, either by their own efforts or via trafficking arrangements, leaving them unmonitored with regard to economic activity or health status.

A significant question, which DfID poses, is this: can policies be derived which support aspects of migration that facilitate development in poorer countries, while reducing or combating the negative impacts?

The reality is that it is now too late to avoid a significant degree of climate change and the resulting growth of migration. What matters now with regard to migration is adaptation:agricultural, demographic and legislative — but mostly political.

Jon D. Unruh is at McGill University, Montreal, Canada.