IPCC《全球1.5℃增暖特别报告》冰冻圈变化及其影响解读

Interpretation of IPCC SR1.5 on cryosphere change and its impacts

在气候系统五大圈层中,冰冻圈对气候变化高度敏感,近几十年来气候变暖已引起全球冰川、冻土、积雪和海冰等冰冻圈要素加速退缩,进而对区域水资源、生态环境、社会经济发展和人类福祉产生了深远影响。2018 年10 月,IPCC 在韩国仁川公布了《全球1.5℃增暖特别报告》(SR1.5)。报告较系统地呈现了关于全球1.5℃温升目标的基本科学认知,并探讨了可持续发展及消除贫困目标下加强全球响应的路径。在冰冻圈相关内容方面,报告呈现了有关全球1.5℃和2℃温升下冰冻圈(主要是海冰和多年冻土)变化及其对大气圈、水圈、生物圈、岩石圈和人类圈影响的一些亮点结论,还关注了全球1.5℃和2℃温升下冰冻圈相关的气候变化热点(区)和地球系统临界因素。报告指出,随着温度不断升高,冰冻圈及其相关要素和热点(区)面临的风险将不断增加,但将全球温升控制在1.5℃而不是2℃或更高时的风险将大大降低。

The cryosphere is highly sensitive to climate change among the five major spheres of climate system. Past decades, with the anthropogenic climate warming, has seen an accelerated retreat of the global cryosphere (including mountain glacier, frozen soil, snow cover and sea ice, etc.), which has also seriously affected global climate system and regional water resources, eco-environment, socio-economic development and human well-being. The IPCC Special Report on Global Warming of 1.5℃(SR1.5) was issued in October 2018, it systematically presented basic scientific understanding of 1.5℃ global warming above pre-industrial levels and related global greenhouse gas emission pathways in the context of sustainable development and poverty eradication. In the cryosphere and related aspects, SR1.5 mainly projected some cryospheric changes (mainly sea ice, permafrost) and their impacts on the atmosphere, hydrosphere, biosphere, lithosphere and anthroposphere at a global average warming of 1.5℃ and higher levels of warming. It also focused on many climate change hotspots and tipping points under different global temperature goals, most of which are related to the cryosphere. As the temperature continues to rise, the risks to the cryosphere and its associated hotspots and tipping points will continue to increase. Limiting global warming to 1.5℃ compared to 2℃ or higher level is projected to lower the risks. However, frankly, SR1.5 has not given deep attention to the change and its impacts. In the future, it is necessary to deepen the research on the changes of the cryosphere and its related impacts and adaptation under different climatic scenarios, especially with the global 1.5℃ and 2℃ temperature goals and tipping points, thereby to explore a more sustainable and resilient pathway in the cryosphere affected regions.