Basque Centre for Climate Change (BC3), Leioa, Spain.
Basque Centre for Climate Change (BC3), Leioa, Spain.
Lancet Planet Health. 2018 Mar;2(3):e126-e133. doi: 10.1016/S2542-5196(18)30029-9. Epub 2018 Mar 2.
Although the co-benefits from addressing problems related to both climate change and air pollution have been recognised, there is not much evidence comparing the mitigation costs and economic benefits of air pollution reduction for alternative approaches to meeting greenhouse gas targets. We analysed the extent to which health co-benefits would compensate the mitigation cost of achieving the targets of the Paris climate agreement (2°C and 1·5°C) under different scenarios in which the emissions abatement effort is shared between countries in accordance with three established equity criteria.
Our study had three stages. First, we used an integrated assessment model, the Global Change Assessment Model (GCAM), to investigate the emission (greenhouse gases and air pollutants) pathways and abatement costs of a set of scenarios with varying temperature objectives (nationally determined contributions, 2°C, or 1·5°C) and approaches to the distribution of climate change methods (capability, constant emission ratios, and equal per capita). The resulting emissions pathways were transferred to an air quality model (TM5-FASST) to estimate the concentrations of particulate matter and ozone in the atmosphere and the resulting associated premature deaths and morbidity. We then applied a monetary value to these health impacts by use of a term called the value of statistical life and compared these values with those of the mitigation costs calculated from GCAM, both globally and regionally. Our analysis looked forward to 2050 in accordance with the socioeconomic narrative Shared Socioeconomic Pathways 2.
The health co-benefits substantially outweighed the policy cost of achieving the target for all of the scenarios that we analysed. In some of the mitigation strategies, the median co-benefits were double the median costs at a global level. The ratio of health co-benefit to mitigation cost ranged from 1·4 to 2·45, depending on the scenario. At the regional level, the costs of reducing greenhouse gas emissions could be compensated with the health co-benefits alone for China and India, whereas the proportion the co-benefits covered varied but could be substantial in the European Union (7-84%) and USA (10-41%), respectively. Finally, we found that the extra effort of trying to pursue the 1·5°C target instead of the 2°C target would generate a substantial net benefit in India (US$3·28-8·4 trillion) and China ($0·27-2·31 trillion), although this positive result was not seen in the other regions.
Substantial health gains can be achieved from taking action to prevent climate change, independent of any future reductions in damages due to climate change. Some countries, such as China and India, could justify stringent mitigation efforts just by including health co-benefits in the analysis. Our results also suggest that the statement in the Paris Agreement to pursue efforts to limit temperature increase to 1·5°C could make economic sense in some scenarios and countries if health co-benefits are taken into account.
European Union's Horizon 2020 research and innovation programme.
尽管人们已经认识到解决气候变化和空气污染问题带来的共同效益，但对于为实现温室气体减排目标而采取的替代方法，减少空气污染的缓解成本和经济效益方面的证据并不多。我们分析了在根据三种既定公平标准在各国之间分担减排工作的情况下，不同情景下实现巴黎气候协议（2°C 和 1.5°C）目标的健康共同效益将在多大程度上弥补缓解成本。
我们的研究分三个阶段进行。首先，我们使用综合评估模型全球变化评估模型（GCAM），研究了具有不同温度目标（国家确定的贡献、2°C 或 1.5°C）和气候变化方法分配方法（能力、恒定排放比和人均平等）的一系列情景下的排放（温室气体和空气污染物）途径和缓解成本。将由此产生的排放途径转移到空气质量模型（TM5-FASST）中，以估算大气中颗粒物和臭氧的浓度以及由此导致的过早死亡和发病。然后，我们通过使用所谓的统计生命价值来为这些健康影响赋予货币价值，并将这些价值与从 GCAM 计算得出的缓解成本进行比较，包括全球和区域。我们的分析根据共享社会经济路径 2 的社会经济叙述，展望了 2050 年。
对于我们分析的所有情景，健康共同效益都大大超过了实现目标的政策成本。在一些缓解策略中，中值共同效益是全球中值成本的两倍。健康共同效益与缓解成本的比值在 1.4 到 2.45 之间，具体取决于情景。在区域层面，减少温室气体排放的成本可以仅用健康共同效益来弥补，中国和印度就是如此，而欧盟（7-84%）和美国（10-41%）的共同效益所占比例则有所不同，但可能很大。最后，我们发现，与 2°C 目标相比，争取实现 1.5°C 目标将在印度（3.28-8.4 万亿美元）和中国（0.27-2.31 万亿美元）产生巨大的净效益，尽管在其他地区没有看到这种积极结果。
采取行动预防气候变化可以带来巨大的健康收益，而与未来因气候变化造成的损害减少无关。中国和印度等一些国家，如果在分析中包括健康共同效益，就可以证明采取严格的缓解措施是合理的。我们的结果还表明，如果考虑健康共同效益，《巴黎协定》中努力将温度升高限制在 1.5°C 的说法在某些情况下和某些国家可能具有经济意义。
欧盟的地平线 2020 研究和创新计划。
