Elizabeth Ferris, Institute for the Study of International Migration, Georgetown University

There’s a lot we don’t know about climate change.  But since the very first report of the Intergovernmental Panel on Climate Change (IPCC) in 1990, it has been clear that people will have to move because of the effects of climate change.  Global warming, sea level rise, more heatwaves, stronger storms, longer droughts – all of these will lead people to abandon their communities.  In the United States, some will see the handwriting on the wall and move long before conditions become desperate.  Others will be forced to move at short notice – witness the tens of thousands of people displaced by this month’s  California wildfires and the hundreds of thousands of Puerto Ricans who moved to the mainland US after Hurricane Maria.  For some, displacement will be temporary, but some will likely never return.  Others will attempt try to relocate their whole communities – as a number of Alaskan indigenous communities have been trying to do for decades as coastal erosion makes their ports unusable and melting permafrost destroys their sewer systems.  Others will accept individual buy-out offers from state governments as in New Jersey’s Blue Acres program and move away from areas experiencing recurrent flooding.

The consequences of these movements of people are many.  It’s likely that cities everywhere will see their populations grow as people move from areas that have become uninhabitable because of the effects of climate change.  Local governments will feel the effects; among other things, when people move away from coastal communities, the tax base decreases.  And when people move from expensive beachfront properties to higher ground, they sometimes displace poorer communities in the process as is evident in parts of South Florida, giving rise to a new term: climate gentrification.

The global estimates of the number of people who will have to move because of the effects of climate change vary enormously – from 50 million to 1 billion by 2050.  That’s a big range and a lot of the estimates are pure speculation. But even at the lower end of the estimates, we’re talking about millions and millions of people on the move.  Most of these people will move within the borders of their countries – they will be internally displaced people (IDPs).  A recent flagship report by the World Bank projects that  over 140 million people in three regions will be displaced within their countries by the year 2050.  Presently the world is not doing a very good job at protecting the 40 million people who have been displaced internally because of war, conflict and human rights violations.  How will it cope with hundreds of millions of displaced people in the future?   While most of the world’s 40 million IDPs live in developing countries, displacement caused by the effects of climate change will affect rich and poor communities alike.  But everywhere it is likely to be those living in poor and marginal communities – those living on the edge – who are likely to bear the effects of climate change.

We need to start thinking seriously about this now.   We – governments at all levels, academics from many disciplines, civil society groups – need to devote more attention and more creative thought to migration caused by the effects of climate change.  We need to identify the areas where people are likely to be forced to ‘retreat’ and see if there are measures that can be taken to enable them to stay where they are.  This might mean physical protection – like planting mangrove forests and building sea walls (but if you think building a border wall with Mexico is expensive, wait until you start thinking about sea walls to protect American coastlines.) Or it might mean retrofitting homes to survive stronger storms and raising highways to withstand rising tides.  But it also might mean putting serious money into creating climate resilient communities – which includes a range of policy options from strengthening building codes to changing flood insurance policies.  It also means thinking about how to avoid displacement and at the same time to see migration – and relocations – as a form of adaptation to climate change.  Here at Georgetown, scholars are already working in this direction.  For example, ISIM has worked with the UN to develop a Toolkit for Planned Relocations and Georgetown Law School’s Climate Center has researched communities’ climate resilience policies and is currently working on tools for ‘coastal retreat.’

Climate change certainly isn’t the only factor compelling people to leave their communities, but it is already an important driver of migration and all signs point to it becoming more important in the future.