A United Nations report, issued early this morning in Copenhagen
, insists that reversing climate change is indeed affordable but it must start with cutting emissions to zero by 2100.
The 40-page report, including the work from a stunning group of 800 scientists, points to more heat extremes and unprecedented sea levels.
"Science has spoken. There is no ambiguity in the message," said U.N. Secretary-General Ban Ki-moon. "Leaders must act. But time is not on our side."
But unless austere measures to reduce emissions are taken, scientists say, "warming by the end of the 21st century will bring high risks of severe, widespread and irreversible impacts globally." Specifically, experts are calling for world emissions to drop by between 40 percent and 70 percent by 2050 and to near zero by 2100.
The planet's major emitters are China, the United States and the European Union.
"There is a myth that climate action will cost heavily," said Ban Ki-moon, "But inaction will cost much more. We have to first lower the temperature as you will do with your children, that is what we are doing, that requires some massive, urgent and immediate action."