(The Guardian) May 11, 2011 – Imagine if the world acted only when 100% scientific proof was in place.

We would still be insulating buildings with cancer-causing asbestos and fuelling cars with lead additives, damaging babies’ brains. The circulation in fridges would also be done by chemicals that, by thinning the Earth’s protective ozone layer, would probably have led to a sharp increase in cases of skin cancer worldwide.

But this is not happening. In those cases, governments assessed the emerging science, consulted on the risks and accepted that the evidence outweighed the uncertainties.

Internationally, it is called the precautionary approach: you and I might call it acting responsibly, prudently or just being smart.

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.

In 2008 analysts for the Pentagon in the US concluded that extreme weather events linked with climate change could lead to mass migration in some parts of the world.

This year the International Institute for Strategic Studies in the UK stated: “In areas with weak or brittle states, climate change will increase the risks of resource shortages, mass migrations and civil conflict.”

Some attempts, such as the 2005 estimate, have also been trying to put possible numbers on the likely numbers displaced.

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.

“Research from other sources suggests that many millions of people are also displaced annually as a result of slow-onset climate-related disasters such as drought,” it adds.

Munich Re, the re-insurance company, recently concluded that in 2010 “The high number of weather-related natural catastrophes and record temperatures, both globally and in different regions of the world, provide further indications of advancing climate change.”

The company mentions the floods in Pakistan, where about a million people were displaced.

We could say with greater certainty that many victims of rising greenhouse gas emissions were already with us, if only the existing science was able to disentangle the climate signature from the other complexities and challenges many people across the world increasingly face.

The question we must continuously ask ourselves in the face of scientific complexity and uncertainty, but also growing evidence of climate change, is at what point precaution, common sense or prudent risk management demands action.

The role of institutions such as the United Nations Environment Programme (UNEP) is to continuously review emerging science, subject it to careful peer review and ensure that it is available to public policymakers and, indeed, the public.

To declare a phenomenon such as climate change non-existent until we have unravelled all aspects of atmospheric science and impacts on the biosphere and on human beings would be reckless and irresponsible.

Although reviewing science is an integral part of knowledge generation, we should not allow the critique to paralyse emerging science on climate change from reaching society – especially when the lives and livelihoods of considerable numbers of people are at risk.

Achim Steiner is UN under-secretary general and executive director of UNEP

Source: The Guardian