The charity Christian Aid projects that up to a billion people could be displaced from their homes by 2050 as a result of climate change, in a report, “Human tide: the real migration crisis“, published this week. That would be around one-in-eight of the world’s population. Most will be displaced within their own countries; many will be absorbed by temporary housing in urbanising areas.

The figure is on top of the existing 160 million ‘forced migrants’ it calculates as a result of wars, disasters, and large-scale development projects.

Far more people, it says, are now displaced around the world than
even immediately after the Second World War. The current total of forced migrants includes:

  • 25 million people displaced by conflict and extreme humanrights abuses who remain within their own countries.
  • 25 million people displaced by disasters, who also remain within their own countries.
  • 105 million people displaced by ‘development’ projects such as
    dams, mines, roads, factories, plantations and wildlife reserves. Most remain within their own countries.
  • 8.5 million refugees, who fled their own countries and been granted asylum elsewhere.

More than half of the billion forced migrants identified in the report come from large scale development projects, such as dams. Another quarter are directly displaced through extreme weather effects related to climate change. The total is made up as follows:

  • 645 million people displaced by development projects such as dams and mines (at the current rate of 15 million people a year).
  • 250 million people permanently displaced by climate change-related phenomena such as floods, droughts, famines and hurricanes.
  • 50 million people displaced by confl ict and extreme human rights abuses. This assumes a rate of displacement of roughly 1 million people a year, which is conservative.
  • 50 million people displaced by natural disasters. Again, this conservatively assumes that around 1 million people will be displaced in this way every year.
  • 5 million people will flee their own countries and be accepted as refugees.

Looking at the methodology, it appears that they’ve effectively extrapolated existing trends and projected them forwards in a ‘straight line’ basis, although the sources they’ve used to do this are well-referenced and they seem mostly to have been conservative in their assumptions. But it does seem that scenarios would help understand where changes in values, or intervention, might change current patterns.

For example: dams projects are identified in Fred Pearce’s book When The River Runs Dry, published in paperback last month, and which I summarised in another post, as typically being counterproductive (at least in the medium to long term) in managing water or aiding irrigation. Given that water engineers are still fond of them, but campaigners increasingly hostile, where’s the point at which dams no longer attract substantial funding from, for example, the World Bank?