National climate change mitigation legislation, strategy and targets: a global update

Global climate change governance has changed substantially in the last decade, with a shift in focus from negotiating globally agreed greenhouse gas (GHG) reduction targets to nationally determined contributions, as enshrined in the 2015 Paris Agreement. This paper analyses trends in adoption of national climate legislation and strategies, GHG targets, and renewable and energy efficiency targets in almost all UNFCCC Parties, focusing on the period from 2007 to 2017. The uniqueness and added value of this paper reside in its broad sweep of countries, the more than decade-long coverage and the use of objective metrics rather than normative judgements. Key results show that national climate legislation and strategies witnessed a strong increase in the first half of the assessed decade, likely due to the political lead up to the Copenhagen Climate Conference in 2009, but have somewhat stagnated in recent years, currently covering 70% of global GHG emissions (almost 50% of countries). In comparison, the coverage of GHG targets increased considerably in the run up to adoption of the Paris Agreement and 89% of global GHG emissions are currently covered by such targets. Renewable energy targets saw a steady spread, with 79% of the global GHG emissions covered in 2017 compared to 45% in 2007, with a steep increase in developing countries. Key policy insightsThe number of countries that have national legislation and strategies in place increased strongly up to 2012, but the increase has levelled off in recent years, now covering 70% of global emissions by 2017 (48% of countries and 76% of global population).Economy-wide GHG reduction targets witnessed a strong increase in the build up to 2015 and are adopted by countries covering 89% of global GHG emissions (76% not counting USA) and 90% of global population (86% not counting USA) in 2017.Renewable energy targets saw a steady increase throughout the last decade with coverage of countries in 2017 comparable to that of GHG targets.Key shifts in national measures coincide with landmark international events – an increase in legislation and strategy in the build-up to the Copenhagen Climate Conference and an increase in targets around the Paris Agreement – emphasizing the importance of the international process to maintaining national momentum. The number of countries that have national legislation and strategies in place increased strongly up to 2012, but the increase has levelled off in recent years, now covering 70% of global emissions by 2017 (48% of countries and 76% of global population). Economy-wide GHG reduction targets witnessed a strong increase in the build up to 2015 and are adopted by countries covering 89% of global GHG emissions (76% not counting USA) and 90% of global population (86% not counting USA) in 2017. Renewable energy targets saw a steady increase throughout the last decade with coverage of countries in 2017 comparable to that of GHG targets. Key shifts in national measures coincide with landmark international events – an increase in legislation and strategy in the build-up to the Copenhagen Climate Conference and an increase in targets around the Paris Agreement – emphasizing the importance of the international process to maintaining national momentum.

近十年来，全球气候变化治理格局发生显著变革，治理重心从磋商全球统一的温室气体（Greenhouse Gas, GHG）减排目标，转向落实2015年《巴黎协定（Paris Agreement）》所确立的国家自主贡献（Nationally Determined Contributions, NDC）机制。本研究分析了几乎所有《联合国气候变化框架公约（United Nations Framework Convention on Climate Change, UNFCCC）》缔约方在2007年至2017年间的国家气候立法与战略、温室气体减排目标以及可再生能源与能源效率目标的推行趋势。本研究的独特性与学术价值在于其覆盖的国家范围广泛、研究周期长达十余年，且采用客观量化指标而非规范性评判展开分析。核心研究结果显示，国家气候立法与战略在评估时段的前半段增幅显著，这大概率与2009年哥本哈根气候大会（Copenhagen Climate Conference）前的政治筹备进程相关，但近年增长态势有所趋缓；截至当前，此类立法与战略覆盖了全球70%的温室气体排放（对应近50%的缔约方）。相较而言，温室气体减排目标的覆盖范围在《巴黎协定》达成前得到大幅提升，目前全球89%的温室气体排放已被此类目标覆盖。可再生能源目标则呈现稳步推广态势：2017年其覆盖的全球温室气体排放占比达79%，而2007年这一比例仅为45%，其中发展中国家的增长幅度尤为显著。核心政策洞察：已制定并推行国家气候立法与战略的国家数量在2012年前实现强劲增长，但近年增速趋于平缓；截至2017年，此类举措已覆盖全球70%的温室气体排放（对应48%的缔约方与76%的全球人口）。全经济范围温室气体减排目标在2015年达成前迎来大幅增长，2017年时，实施此类目标的缔约方覆盖了全球89%的温室气体排放（若不计美国则为76%）与90%的全球人口（若不计美国则为86%）。可再生能源目标在过去十年间持续稳步提升，2017年其覆盖的缔约方范围与温室气体减排目标相当。国家气候举措的关键转变与标志性国际事件高度契合：哥本哈根气候大会筹备期间的立法与战略增长，以及《巴黎协定》达成前后的目标增设，这凸显了国际进程对维持国内气候行动动力的重要性。已制定并推行国家气候立法与战略的国家数量在2012年前实现强劲增长，但近年增速趋于平缓；截至2017年，此类举措已覆盖全球70%的温室气体排放（对应48%的缔约方与76%的全球人口）。全经济范围温室气体减排目标在2015年达成前迎来大幅增长，2017年时，实施此类目标的缔约方覆盖了全球89%的温室气体排放（若不计美国则为76%）与90%的全球人口（若不计美国则为86%）。可再生能源目标在过去十年间持续稳步提升，2017年其覆盖的缔约方范围与温室气体减排目标相当。国家气候举措的关键转变与标志性国际事件高度契合：哥本哈根气候大会筹备期间的立法与战略增长，以及《巴黎协定》达成前后的目标增设，这凸显了国际进程对维持国内气候行动动力的重要性。