O.R. Models to Guide Flow of Climate Change Migrants

by Nigel Cummings

No one knows how many people are being driven to cities by environmental factors exacerbated by climate change, but experts agree that before long we will find out.

Daily, we hear stories about seasonal patterns changing, and farmers not being able to sustain the same level of production as a result. Climate change is seen to be one of the most serious threats to sustainable development, with adverse effects expected on the environment, human health, food security, economic activity, natural resources, and physical infrastructure. A growing body of evidence, including analyses from military experts in the United States and Europe, supports the estimate that by midcentury, climate change will make vast parts of Africa and Asia uninhabitable. Analysts say this could trigger a migration the size of which the world has never before seen. Low-lying areas in many developing countries could be vulnerable to flooding from rising sea levels and arid areas could become uninhabitable as water becomes scarcer, meaning that millions of people will need to migrate.

Some of the big questions remain unanswered: How many people will really move? Where will they go? How will they go? Will they return?

Now it seems, O.R. is ready to be applied to such problems, particularly in guiding policymakers in making decisions about relocating people within their own countries as a way of adapting to climate change. A mathematical model has been developed in the Decision Sciences and Information Systems department at Lethbridge University, Canada, which can be used to calculate how many people an area could support in the event of it becoming less habitable; how many people could remain and implement adaptation techniques and how many people another area in the country could absorb.

The model also estimates the economic impact of various relocation scenarios and the cost of relocation and adaptation assess whether it is economically viable. The model can take into account people’s preferences about relocation. Sajjad Zahir, Professor of Decision Sciences and Information Systems at Lethbridge, and principal author of the research which had led to the formulation and activation of the new model, says that “planning the relocation of people because of climate change is a new field of research.”As a result, the researchers do not yet have sufficient real-world data with which to test the model, but they plan to expand it to incorporate conflict resolution mechanisms and better take into account people’s preferences.

The model could enable governments to relocate people in high-risk areas without affecting the economic stability of the region and allow those that stay to use environmental adaptation strategies such as elevated housing and barrier walls in flood-prone areas.

Meanwhile, In the UK a team of 10 Scottish scientists are to attempt (from August 2009) to crack problems such as predicting exact climate change effects by using algorithms. Some of these numerical challenges presented by modern science are to be tackled by experts from Edinburgh University, Heriot-Watt University and Strathclyde University. £8m funding has been allocated to the ‘Numerical Algorithms and Intelligent Software (Nais)’ team. The scientists will be looking at ways to solve the massive numerical problems posed by advances in modern-day science, medicine and engineering, where enormous amounts of data are needed to be processed because of the amount of variables involved.

First published to members of the Operational Research Society in Inside O.R. August 2009