Answer:
The evidence for global warming is now considered "exceptionally strong and beyond doubt" and actions this decade will determine the impact of climate change for the rest of the century .
Greenhouse gas emissions must peak and then begin to fall rapidly within the next few years if the world is to avoid dangerous warming of up to 7 degrees and beyond in his century. "If you leave the peaking year until 2020 you are going to have to reduce emissions at 9 per cent a year after that," Professor Will Steffen said. "I think this is almost impossible to do unless you put the economy on a war footing." This provides us with a clear incentive and advantage in doing something now to slow global warming while it is still possible without social and economic upheaval.
The only real disadvantage in doing something now to slow global warming is political. Politicians hate taking action that may have a short-term cost to anyone, but for which the greatest benefits will accrue after they have retired from political office.