The Dynamic Integrated Climate-Economy (DICE) model is one of the most influential Integrated Assessment Models available. Its founder Professor William Nordhaus was recently awarded Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel due to his pioneering work on the economics of climate change. In a recent paper in American Economic Journal: Economic Policy, Nordhaus uses the model to conclude that a 2.5°C target is almost out of reach. In this paper, we update DICE 2016 R2 with state-of-the-art models of the carbon cycle, heat uptake into the oceans, and the role of non-CO₂ forcers. We find that the allowable remaining carbon budget (over the period 2015–2100) to meet a 2.5°C target to be 2,360 GtCO₂ whereas the estimate obtained using DICE 2016 R2 is about 460 GtCO₂. Nordhaus's estimate of the remaining carbon budget for this target is hence five times lower than estimates made by our updated DICE. We also compare our results with estimates by the Intergovernmental Panel on Climate Change (IPCC), and find our results to be in line with the carbon budgets presented in IPCC SR 1.5. We explain the reasons behind the difference between our result and that of Nordhaus and propose that an updated climate module in DICE is warranted.

中文翻译：

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DICE 和雄心勃勃的气候目标的碳预算

动态综合气候经济 (DICE) 模型是最有影响力的综合评估模型之一。由于他在气候变化经济学方面的开创性工作，其创始人威廉·诺德豪斯教授最近被授予瑞典央行经济学奖以纪念阿尔弗雷德·诺贝尔。在《美国经济杂志：经济政策》最近发表的一篇论文中，诺德豪斯使用该模型得出的结论是，2.5°C 的目标几乎遥不可及。在本文中，我们使用最先进的碳循环模型、海洋热吸收和非 CO ₂强迫作用更新了 DICE 2016 R2 。我们发现，满足 2.5°C 目标的可允许剩余碳预算（2015-2100 年期间）为 2,360 GtCO ₂而使用 DICE 2016 R2 获得的估计值约为 460 GtCO ₂。因此，诺德豪斯对该目标剩余碳预算的估计比我们更新后的 DICE 所做的估计低五倍。我们还将我们的结果与政府间气候变化专门委员会 (IPCC) 的估计进行比较，发现我们的结果与 IPCC SR 1.5 中提出的碳预算一致。我们解释了我们的结果与 Nordhaus 的结果之间存在差异的原因，并建议有必要在 DICE 中更新气候模块。