FAIR v1.3: a simple emissions-based impulse response and carbon cycle model
FAIR v1.3: a simple emissions-based impulse response and carbon cycle model
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DOI：
10.5194/gmd-11-2273-2018
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发表时间：
2018-06-18
影响因子：
5.1
通讯作者：
Regayre, Leighton A.
中科院分区：
文献类型：
--
作者：
Smith, Christopher J.;Forster, Piers M.;Regayre, Leighton A.
如果简单的气候模式能够复制复杂的完全耦合的地球系统模式的各个方面，那么它们可能是有价值的。可以产生更大的集合，从而能够对未来气候变化进行概率性观察。提出了一个简单的基于排放的气候模型FAIR，该模型计算大气中温室气体的浓度以及温室气体、气溶胶、臭氧和其他因子的有效辐射强迫（ERF）。模型运行仅限于1880年至2016年观测到的温度变化，并在代表性浓度路径（RCP）情景下产生一系列未来预测。平衡气候敏感性（ECS）、瞬时气候响应（TCR）和瞬时气候对CO2累积排放量的响应（TCRE）的约束估计值分别为2.86（2.01 ~ 4.22）K、1.53（1.05 ~ 2.41）K和1.40（0.96 ~ 2.23）K（1000 GtC）（-1）（中值和5-95%可信区间）。这些数据与政府间气候变化专门委员会（气专委）第五次评估报告（AR 5）的可能范围非常一致，并指出，AR 5的估计数是根据气候模型、观测和专家判断综合得出的。未来的温度预测范围和ECS，TCR和TCRE的估计范围对ECS/TCR参数的先验分布有些敏感，但对CO2加倍或用于约束集合的观测温度数据集的ERF不太敏感。考虑到这些敏感性，没有证据表明，观测约束TCR或ECS的中位数和可信范围不同于气候模式得出的估计。由于强迫假设和ECS/TCR分布的差异，约束FAIR模型集合中RCP8.5下2081-2100年的温度预测范围比AR 5中报告的基于排放的估计低半度。
Simple climate models can be valuable if they are able to replicate aspects of complex fully coupled earth system models. Larger ensembles can be produced, enabling a probabilistic view of future climate change. A simple emissions-based climate model, FAIR, is presented, which calculates atmospheric concentrations of greenhouse gases and effective radiative forcing (ERF) from greenhouse gases, aerosols, ozone and other agents. Model runs are constrained to observed temperature change from 1880 to 2016 and produce a range of future projections under the Representative Concentration Pathway (RCP) scenarios. The constrained estimates of equilibrium climate sensitivity (ECS), transient climate response (TCR) and transient climate response to cumulative CO2 emissions (TCRE) are 2.86 (2.01 to 4.22) K, 1.53 (1.05 to 2.41) K and 1.40 (0.96 to 2.23) K (1000 GtC)(-1) (median and 5-95% credible intervals). These are in good agreement with the likely Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) range, noting that AR5 estimates were derived from a combination of climate models, observations and expert judgement. The ranges of future projections of temperature and ranges of estimates of ECS, TCR and TCRE are somewhat sensitive to the prior distributions of ECS/TCR parameters but less sensitive to the ERF from a doubling of CO2 or the observational temperature dataset used to constrain the ensemble. Taking these sensitivities into account, there is no evidence to suggest that the median and credible range of observationally constrained TCR or ECS differ from climate model-derived estimates. The range of temperature projections under RCP8.5 for 2081-2100 in the constrained FAIR model ensemble is lower than the emissions-based estimate reported in AR5 by half a degree, owing to differences in forcing assumptions and ECS/TCR distributions.