Climate migration will not wait for scientific certainty on global warming

Achim Steiner in the Guardian (UK) makes the case for the precautionary principle, an idea that has come in for much ridicule in the US. But some version of it, suitably worded, seems necessary: …Climate change perhaps triggers some of the most polarised debate between precaution and those who say that without scientific perfection it is all just hot air. This has re-surfaced in recent weeks over the issue of climate change and migration.

It has been sparked by a map, produced by a Unep-collaborating centre in Norway, overlapping vulnerable areas of the globe and forecasts of climate impacts. The map was linked to scientific projections, made in 2005, suggesting there might be 50 million "climate refugees" by 2010.

Presenting complex data is a challenge for any public or private institution – in respect of migration, rising populations, unsustainable use of resources, poverty and civil war all contribute to vulnerability in the face of natural and weather-related disasters.

The science has moved on since 2005, as has the debate at about how best to classify people affected by natural hazards, either temporarily or permanently and within or across national borders. Looked at today, the map over-simplifies the message, which is why we asked for it to be removed.

Yet the question remains – are there people being displaced by climate change, and what of the future? These are questions that are likely to be high on nations' minds when the UN security council debates climate change and security in July to review a growing body of informed opinion and evidence.

…The UN Office for the Coordination of Humanitarian Affairs (Ocha) and the Internal Displacement Monitoring Centre (IDMC) looked at the data for 2008. The data suggests that at least 36 million people were displaced by "sudden-onset natural disasters", of whom more than 20 million were displaced owing to the sudden onset of weather-related disasters, including about 6.5 million people because of floods in India….

From 2005, Indonesian refugees gather under an approaching helicopter to receive food and supplies. A US helicopter is transporting supplies, bringing in disaster relief teams and supporting humanitarian airlifts to tsunami-stricken costal regions. U.S. Navy photo by Photographer's Mate Airman Patrick M. Bonafede