中国农业生产净碳效应分异研究

农业具有碳排与碳汇的双重效应。分析和把握不同省区的农业净碳水平,是深入研究农业生产碳排放问题的重要前提。鉴于此,研究基于农用物资投入、稻田、土壤、牲畜养殖等四方面23类主要碳源和以水稻、小麦为代表的15类主要农作物碳汇品种,测算了我国1995—2010年及31个省(市、区)2010年的农业生产碳排量、碳汇量,并在此基础上计算了各自净碳汇量。结果表明:①我国农业生产净碳汇量总体保持上升态势,由1995年的26 736.13×10⁴ t增至2010年的37 697.19×10⁴ t,年均递增2.32%。其中,碳排放量由1995年的24 952.39×10⁴ t增至2010年的29 116.91×10⁴ t,年均递增1.03%;碳汇量由1995年的51 688.51×10⁴ t增至2010年的66 814.10×10⁴ t,年均递增1.73%,碳汇增速明显快于碳排增速,可见我国在农业节能减排方面取得了一定成效。分阶段来看,呈现较为明显的"上升—下降—上升"的三阶段变化特征。②横向来看,区域净碳效应差异明显:农业生产净碳汇绝对量,排在前10位的地区占全国农业生产净碳汇总量的73.02%,而排在后10位的地区仅占全国的1.59%。农业生产碳汇水平,黑龙江、吉林、广西排在前三位,分别高达410.81%、400.94%和356.79%;西藏、青海、福建排在后三位,仅为25.57%、41.55%和103.80%。其中,黑龙江等12个地区农业碳汇水平高于全国同期平均水平(229.47%)。

Regional Differentiation Research on Net Carbon Effect of Agricultural Production in China

Agriculture has double effects of carbon emission and carbon sink. The analysis of net carbon effect of every province is important prerequisites for in-depth studying of agricultural production carbon emission. With such a view, this study calculates the amount of carbon emissions and carbon sink from 1995 to 2010 and that of 31 provinces in 2010, based on the agricultural resources inputs, paddy fields, soil and breeding livestock of 23 categories on the major carbon sources with rice and wheat as the representative of the 15 categories of major crops carbon sink species. On the basis of the above the net carbon sink is concluded. The results showed that: 1)The overall net carbon sink of agricultural production maintains an upward trend from 267.3613 million ton in 1995 to 376.9719 million ton in 2010 with an average annual increasing rate of 2.32%. Carbon emissions increased from 249.5239 million ton in 1995 to 291.1691 million ton in 2010 with an average annual increasing rate of 1.05%; and carbon sink rises from 516.8851 million ton in 1995 to 668.1410 million ton in 2010 with an average annual increasing rate of 1.73%. From the above fact the growth rate of carbon sink is significantly faster than that of carbon emission. This indicates that China has gained certain achievement in agricultural energy reduction. Additionally, it shows "up-down-up" phase-change characteristics. 2) Compared horizonally, the regional difference of net carbon effect is obvious: in the absolute amount of net carbon sink of agricultural production, the top 10 regions accounted for 73.02% of the national overall net carbon sink of agricultural production while that of the last 10 regions was only 1.59%. The level of carbon sinks on agricultural production in Heilongjiang, Jilin and Guangxi come to the top three of 410.81%, 400.94% and 356.79% respectively; Tibet, Qinghai and Fujian are the last three with only 25.57%, 41.55% and 103.80%; among which 12 regions including Jilin are higher than the national average level during the same period (229.47%).