For many small island states, reducing emissions to at least 40% below 1990 levels by 2020, is not a matter of negotiation but a matter of survival.
Old targets, at one time considered ambitious, called for a stabilization of both CO₂ levels, at 450 parts per million, and average global temperature rise, at 2 degrees Celsius.
Many small island states and least developed countries call those targets suicidal.
A Stabilization of CO₂ levels at 350 ppm (well below current CO₂ levels in our atmosphere) is the new target for climate scientists and activists who are serious about mitigating climate change.
40% cuts in green house gas emissions is what it will take to drop CO₂ levels to 350 ppm and save low island countries from being washed away.