Nicholas Stern: The IPCC's report has been prepared by 259 researchers; CO2 might result in "population movements of perhaps hundreds of millions"

World leaders must co-operate on talks for strong new climate change deal | Nicholas Stern | Comment is free | The Observer

The IPCC's report, which has been prepared by 259 researchers from 39 countries, will show even more clearly how human activities, primarily burning fossil fuels and deforestation, are creating a dangerous trend with immense risks for the lives and livelihoods of billions of people around the world from shifts in extreme weather, rising sea levels and other serious problems.
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What we have learned from history is that if people are faced with increased dangers of floods, droughts and other extreme weather, they will try to escape, resulting in population movements of perhaps hundreds of millions, leading to widespread and continued conflict.