Climate change: we can't wait for absolute certainty | Achim Steiner | Environment | guardian.co.uk

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.
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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.