It is that in order to "change course and steer away from critical tipping points... that might lead to rapid and irreversible change", something radical is needed.

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They go further and point to, just as one example of their argument, the way in which population rise could lead to a phase change, a chaotic and of unknown outcome, rapid and irreversible change in our environment.

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Scientists and economists have said this plan risks leading to catastrophic and irreversible climate change.

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Human activities are to blame, Jarraud says, and temperatures are "rapidly approaching" a level which scientists believe could kick-start "far-reaching and irreversible" climate change.

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And we will be back having the same stale arguments month after month, year after year, perhaps decade after decade, all while the danger of climate change grows until it is irreversible.

WHITEHOUSE: President Obama at Copenhagen Climate Change Conference-Morning Plenary Session | The White House

While we hope and pray that the underlying strengths of the global economy will -- once again -- enable it to bounce back, the effects of climate change will be far from temporary and will, indeed, be irreversible.

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