The remaining carbon budget represents the total amount of CO₂ that can still be emitted in the future while limiting global warming to a given temperature target. Remaining carbon budget estimates range widely, however, and this uncertainty can be used to either trivialize the most ambitious mitigation targets by characterizing them as impossible, or to argue that there is ample time to allow for a gradual transition to a low-carbon economy. Neither of these extremes is consistent with our best understanding of the policy implications of remaining carbon budgets. Understanding the scientific and socio-economic uncertainties affecting the size of the remaining carbon budgets, as well as the methodological choices and assumptions that underlie their calculation, is essential before applying them as a policy tool. Here we provide recommendations on how to calculate remaining carbon budgets in a traceable and transparent way, and discuss their uncertainties and implications for both international and national climate policies.

剩余的碳预算代表CO ₂的总量在将全球变暖限制在给定的温度目标的同时，将来仍然可以排放该气体。但是，剩余的碳预算估算范围很广，这种不确定性可以用来将最雄心勃勃的减排目标定性为不可能，从而使其微不足道，或者可以说有足够的时间允许逐步过渡到低碳经济。这两种极端都不符合我们对剩余碳预算的政策含义的最佳理解。在将其用作政策工具之前，必须了解影响剩余碳预算规模的科学和社会经济不确定性，以及构成其计算基础的方法选择和假设。