Climate change, migration, and our water supply systems

Our water supply systems and infrastructure have an incredibly long lifetime of at least several decades, and represent a huge financial value. The associated planning horizons are therefore also quite long. As our world is changing at an ever quicker pace (in terms of technology and our environment), the question arises to what degree this long planning horizon continues to be an asset and when it may become a liability.

The need for resilience and flexibility have been recognized by the water industry, and academics have worked evaluating and developing strategies for improving the (climate) resilience of these systems over the past decade. However, many of the approaches that have been developed focus on dealing with natural disasters, their impact on water supply systems, and a speedy recovery of its operation. There is, however, an additional class of scenarios that needs to be taken more into account: (semi-)permanent state changes, in which things do not or cannot get back to the original state. Examples can be given for both our environment (e.g., depletion of an aquifer with limited recharge, desertification) and our societies and urban systems (e.g., significant changes in population size). In this blog post, I discuss two scenarios of the latter category.

Uncoordinated mass migration

As I have argued in a previous blog post and also in other publications, the pressures that our changing climate and other planetary boundary transgressions will be putting on our societies may be more than they can carry. To summarize, in particular climate change and biodiversity loss will lead to a reduction and geographical shift in food crop yields, which, combined with increasing extreme weather (droughts, floods, extreme temperatures) may drive innumerable people from their homelands, leading to uncoordinated mass migration, potential conflicts, etc. The interactions and cascading effects of these processes have started to receive attention in the scientific literature (e.g., this and this publications).

Coordinated mass migration

A recent book by Gaia Vince called Nomad Century paints a scenario of comparable circumstances, but also offers a mechanism to prevent the collapse scenario: coordinated mass migration from equatorial regions to higher (obviously mostly northern) latitudes. She argues that this would not only save lives on a huge scale, but actually also provide a solution for the challenge of maintaining an economy in an aging society (most developed countries). She does concede that the decision process and implementation would be a challenge.

Evidence for climate-change-induced migration

It seems that there is not yet a clear consensus in the scientific community on to what degree climate change will actually lead to large-scale migrations. For example, even though it is predicted that most atolls will be uninhabitable by the mid-21st century, there is no evidence yet for people moving away from atolls. Will people continue to adapt, or will there be a tipping point at which adaptation becomes increasingly more challenging and people will start to move? For poor countries, researchers do observe that climate-change driven changes in agriculture may increase migration, though some people may be too poor to move. Others also note that economic and political factors often also contribute to migration decisions, and that interactions are complex. Climate refugees do not yet fit the definition that has been applied to refugees so far, affecting the rights and hiding the statistics of these people, but awareness of this issue is growing.

Lessons for the water industry

The time scales that are imposed by our changing environment may be shorter than one would think. More than 1 billion people may be displaced by 2050 – in less than 3 decades – but we do not know if and how such a scenario will unfold. We are, however, likely to be close to or already have reached a globally averaged 2 degrees Celsius above pre-industrial temperatures at that time, well beyond our present-day +1.1 degrees Celsius “new normal” of droughts, forest fires and floodings, in yet another “new normal”.

If the international community, or individual national governments, were to decide that they are going to accommodate and prepare for coordinated mass migrations, that will be the time for the water industry to join the effort of physical preparation (in terms of infrastructure creation and expansion on the destination side and downscaling on the departure side). If mass-migrations would get underway in an unexpected and/or uncoordinated manner, e.g. as a result of extreme weather or large-scale food shortages, or because some social tipping point has been activated, similar measures may be necessary, but on even shorter timescales and in a less well-coordinated manner.

Some things can be done already. These include the following:

  • Investigate and familiarize with coordinated as well as uncoordinated mass migration scenarios.
  • Know your options (resources, technologies, policies) for significant upscaling of total water production and wastewater processing, and/or downscaling of per capita water demand and wastewater production (for the destination side) on relatively short timescales.
  • Start building sufficient flexibility into systems to be able to accommodate these scenarios.

Risk Management and a broad perspective on the effects of climate change

Both the large-scale uncoordinated and the coordinated mass migration scenario could be cast aside as alarmist, irrelevant, or unrealistic. They are not predictions, but merely scenarios, both in terms of the underlying drivers and response strategies. However, though we can argue about their details, we cannot deny the plausibility of these scenarios per se and we cannot argue that their likelihood is negligibly low (we do not know that).  Therefore, the logical conclusion from a risk management perspective is to prepare.