The economic costs of action to mitigate climate change rise non-linearly as action is delayed. If those costs are deferred for 15 years or more, mitigation targets will be impossible to achieve, at any cost.
但有一个重要的附带条件：必须立刻采取行动。遏制气候变化的行动的经济成本会因为拖延而呈现非线性升高。如果推迟15年或以上，遏制目标就无法实现，不管付出多大成本。