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%).