Calculation of CO2 emission derived from land-use change from soybean production at Rio Grande do Sul state, Brazil

ABSTRACT One of the environmental impacts that presents great concern nowadays, the green-house gases (GHG) emissions affect decision-making from both government and private sector. Within this concern is the soybean biodiesel production growing that takes place in Brazil and Rio Grande do Sul State, this last one of main producers of soybean. Based on this, GHG emissions accounting from soybean cultivation and their potential environmental impacts depend on an inventory performing that presents a reality as close as possible in relation to Rio Grande do Sul State. Thus, this work aimed to trace how the soybean cultivation has developed for 20 years at Rio Grande do Sul State (between 1992 and 2013). During this research, a soybean growing, mainly on temporary croplands, that results in a different accounting in relation to current inventories that show soybean cultivation moving forward on forests areas was found. In this case, it was verified that this work, following The Intergovernmntal Panel on Climate Change (IPCC) methodology, the land use change (LUC) occurred in only 15.4% of the area, where soybean cultivation moved forward for 20 years. Finally, this work suggests future discussion for methodologies that encompass soybean cultivation advanced over wetland areas according to what is pointed out in this study.

摘要 温室气体（Greenhouse Gases, GHG）排放是当下广受关注的环境问题之一，其对政府及私营部门的决策均具有显著影响。其中，巴西及南里奥格兰德州（Rio Grande do Sul）的大豆生物柴油产业正持续扩张，而南里奥格兰德州本身便是全球主要大豆产区之一。有鉴于此，大豆种植的温室气体排放核算及其潜在环境影响，需依托尽可能贴合南里奥格兰德州实际状况的排放清单开展相关研究。为此，本研究旨在梳理1992年至2013年间南里奥格兰德州20年的大豆种植发展脉络。研究过程中发现，该区域大豆种植主要依托临时农用地开展，这与当前主流排放清单中“大豆种植扩张侵占林地”的结论存在显著差异。经验证，遵循政府间气候变化专门委员会（Intergovernmental Panel on Climate Change, IPCC）的方法学，本研究所覆盖的20年大豆种植扩张区域中，仅15.4%的面积发生了土地利用变化（Land Use Change, LUC）。最后，基于本研究结论，本研究提出未来需针对大豆种植扩张侵占湿地的相关方法学展开深入探讨。