Instead, the agreement limits itself to responding to the widely accepted goal of keeping carbon-dioxide levels below 450 parts per million, and the rise in average global temperature below 2°C. But are these targets realistic? If not, we must bear in mind the warning of the Stern Report that failure to act now would make taking action in the future much more costly.
反之，协议内容局限在回应普遍接受的将二氧化碳排放量限制在百万分之四百五十，以及将全球平均升温幅度控制在2°C以内的目标。但这样的目标是否现实？如果不现实，我们必须记住《斯特恩报告》的警告，现在不采取措施将使未来付出的代价更加昂贵。