Tubiello Francesco N, Salvatore Mirella, Ferrara Alessandro F, House Jo, Federici Sandro, Rossi Simone, Biancalani Riccardo, Condor Golec Rocio D, Jacobs Heather, Flammini Alessandro, Prosperi Paolo, Cardenas-Galindo Paola, Schmidhuber Josef, Sanz Sanchez Maria J, Srivastava Nalin, Smith Pete
Climate, Energy and Tenure Division, Food and Agriculture Organization of the United Nations, Via Terme di Caracalla, Rome, 00153, Italy.
School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK.
Glob Chang Biol. 2015 Jul;21(7):2655-2660. doi: 10.1111/gcb.12865. Epub 2015 Feb 2.
We refine the information available through the IPCC AR5 with regard to recent trends in global GHG emissions from agriculture, forestry and other land uses (AFOLU), including global emission updates to 2012. Using all three available AFOLU datasets employed for analysis in the IPCC AR5, rather than just one as done in the IPCC AR5 WGIII Summary for Policy Makers, our analyses point to a down-revision of global AFOLU shares of total anthropogenic emissions, while providing important additional information on subsectoral trends. Our findings confirm that the share of AFOLU emissions to the anthropogenic total declined over time. They indicate a decadal average of 28.7 ± 1.5% in the 1990s and 23.6 ± 2.1% in the 2000s and an annual value of 21.2 ± 1.5% in 2010. The IPCC AR5 had indicated a 24% share in 2010. In contrast to previous decades, when emissions from land use (land use, land use change and forestry, including deforestation) were significantly larger than those from agriculture (crop and livestock production), in 2010 agriculture was the larger component, contributing 11.2 ± 0.4% of total GHG emissions, compared to 10.0 ± 1.2% of the land use sector. Deforestation was responsible for only 8% of total anthropogenic emissions in 2010, compared to 12% in the 1990s. Since 2010, the last year assessed by the IPCC AR5, new FAO estimates indicate that land use emissions have remained stable, at about 4.8 Gt CO eq yr in 2012. Emissions minus removals have also remained stable, at 3.2 Gt CO eq yr in 2012. By contrast, agriculture emissions have continued to grow, at roughly 1% annually, and remained larger than the land use sector, reaching 5.4 Gt CO eq yr in 2012. These results are useful to further inform the current climate policy debate on land use, suggesting that more efforts and resources should be directed to further explore options for mitigation in agriculture, much in line with the large efforts devoted to REDD+ in the past decade.
我们完善了政府间气候变化专门委员会(IPCC)第五次评估报告(AR5)中关于农业、林业和其他土地利用(AFOLU)领域近期全球温室气体排放趋势的信息,包括更新至2012年的全球排放数据。我们在分析中使用了IPCC AR5中用于分析的全部三个可用的AFOLU数据集,而不是像IPCC AR5第三工作组政策制定者摘要那样仅使用一个数据集。我们的分析表明,全球AFOLU排放占人为排放总量的份额有所下调,同时还提供了关于各子部门趋势的重要补充信息。我们的研究结果证实,AFOLU排放占人为排放总量的份额随时间下降。结果显示,20世纪90年代十年平均为28.7±1.5%,21世纪头十年为23.6±2.1%,2010年的年值为21.2±1.5%。IPCC AR5曾指出2010年这一份额为24%。与之前几十年不同,此前土地利用(土地利用、土地利用变化和林业,包括森林砍伐)的排放量显著高于农业(作物和畜牧生产)的排放量,而在2010年,农业成为更大的组成部分,占温室气体排放总量的11.2±0.4%,而土地利用部门占10.0±1.2%。2010年,森林砍伐仅占人为排放总量的8%,而在20世纪90年代这一比例为12%。自2010年(IPCC AR5评估的最后一年)以来,联合国粮食及农业组织(FAO)的新估计表明,土地利用排放一直保持稳定,2012年约为48亿吨二氧化碳当量/年。排放减去清除量也一直保持稳定,2012年为32亿吨二氧化碳当量/年。相比之下,农业排放继续以每年约1%的速度增长,且仍高于土地利用部门,2012年达到54亿吨二氧化碳当量/年。这些结果有助于为当前关于土地利用的气候政策辩论提供更多信息,表明应投入更多努力和资源,进一步探索农业减排的选项,这与过去十年为减少毁林和森林退化所致排放并促进森林保护(REDD+)所做的巨大努力非常一致。