Thank you for downloading the more or less podcast.

We're your weekly guide to the numbers in the news and in life.

I'm Tom Coles.

Today, with the COP Climate Conference underway in Dubai I'm going to be taking a look at a very big number

that's been bouncing around the climate change debate in recent years.

The idea that there might be a billion climate refugees at some point this century.

To get us started, here's an example of that number being used by former US Vice President

Al Gore earlier this year, as he set out the effects of climate change.

Sucking the moisture out of the land and creating the droughts and melting the eyes and raising the

sea level and causing these waves of climate refugees predicted to reach one billion in this century.

Look at the xenophobia and political authoritarian trends that have come from just a few million refugees. What about a

billion? We would lose our capacity for self-governance on this world.

Now I'm going to stop using the term refugees here as it has a specific legal meaning that doesn't currently apply to

climate migrants. But this claim that someone has predicted a billion climate migrants has been

widely reported and repeated. But is it a good

prediction? The first thing to say is that on more or less we're often skeptical

of suspiciously round numbers, but should we put such cynical thoughts to bed in this case?

Here's Sam Huckstead from a think tank called the Center for Global Development.

Migration has always been anticipated to happen in the context of climate change.

But the numbers that have been produced, which started to gain traction really in the 1990s,

have taken on something of a life of their own, despite the fact that in the scientific

community there's really stable consensus that these numbers don't deserve the credence they

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