Carbon footprint of Chinaʹs crop production—An estimation using agro-statistics data over 1993–2007

Characterizing the carbon footprint (CF) of agricultural production offers key information for pursuing low carbon agriculture and food consumption. While China has long strived for increasing food production capacity for its large and still growing population, the high emissions cost, especially from the over use of agro-chemicals, has been widely debated for the last decade. However, the CF of Chinaʹs crop production has not yet been assessed. This paper reports a basic estimate of CF of crop production using national statistical data available for the period of 1993–2007. The dataset includes the amount of individual agricultural inputs (fertilizer, pesticide, diesel, plastic film, etc.), cultivation area and total of production whole crops. Using the emission factors estimated for Chinaʹs agricultural features and available abroad, the mean overall CF of Chinaʹs crop production was estimated to be 0.78 ± 0.08 tCE ha−1 yr−1 and 0.11 ± 0.01 tCE t−1 yr−1, for land use and bulk production respectively. For the duration the data covered, the carbon intensity under cultivation land use was seen to increase since 1993. Among the total, fertilizer induced emissions exerted the largest contribution of ∼60%, being 0.45 ± 0.04 tCE per ha and 0.07 ± 0.01 tCE per ton of production, on average. Compared to the UK, the estimated overall CF of Chinaʹs crop production was higher in terms of cultivation land use. While there was a significant positive correlation of carbon intensity with total production, carbon efficiency was shown in a decreasing trend during 2003-2007. Therefore, low carbon agriculture should be pursued, and the priority should be given to reducing fertilizer application in agriculture of China. However, for developing best management practices for climate change mitigation in crop production of China, further studies of crop and regional specific CFs and the variation with climate conditions and agricultural managements are needed.