Future Expansion Of Agriculture and Pasture Acts to Amplify Atmospheric CO2 Levels in Response to Fossil-Fuel and Land-Use Change Emissions
Future Expansion Of Agriculture and Pasture Acts to Amplify Atmospheric CO2 Levels in Response to Fossil-Fuel and Land-Use Change Emissions
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未来扩大农业和牧场法案以提高大气二氧化碳水平，以应对化石燃料和土地利用变化排放
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
P. Ciais
中科院分区：
文献类型：
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作者：
V. Gitz;P. Ciais
作物和牧场的扩张损害了森林，导致大气中二氧化碳的增加。第一个明显的原因是森林生物量和土壤碳在转换过程中和转换后的损失。第二个通常被忽视的原因是碳的停留时间减少，例如，当森林或草地转化为耕地时。这降低了全球陆地生物圈的汇容量，从而可能放大由于化石和土地使用碳释放造成的大气CO2上升。对于IPCC A2未来情景，其特点是高化石和高土地利用排放，我们表明，土地利用放大器效应增加了61 ppm额外的二氧化碳在大气中，到2100年相比，前处理的土地利用过程中的碳模型。调查的每六个土地利用过渡（森林参与作物，森林参与牧场，草地参与作物）的放大器效应的个人贡献表明，清除森林和草地耕地解释了大部分的CO2放大。放大效应比同一作者以前的分析高出50%，该分析既没有考虑牧场的砍伐，也没有考虑草地的开垦。这种放大效应在敏感性测试中进一步研究，其中净初级生产力被认为是独立的大气CO2。我们还表明，土地利用的变化，这已经发生在不久的过去，有很强的惯性在释放CO2，并将有助于约1/3的放大效应，到2100年。这些结果表明，有一个额外的大气层的好处，保持原始生态系统与高周转时间。
The expansion of crop and pastures to the detriment of forests results in an increase in atmospheric CO2. The first obvious cause is the loss of forest biomass and soil carbon during and after conversion. The second, generally ignored cause, is the reduction of the residence time of carbon when, for example, forests or grasslands are converted to cultivated land. This decreases the sink capacity of the global terrestrial biosphere, and thereby may amplify the atmospheric CO2 rise due to fossil and land-use carbon release. For the IPCC A2 future scenario, characterized by high fossil and high land-use emissions, we show that the land-use amplifier effect adds 61 ppm extra CO2 in the atmosphere by 2100 as compared to former treatment of land-use processes in carbon models. Investigating the individual contribution of each of the six land-use transitions (forest ↔ crop, forest ↔ pasture, grassland ↔ crop) to the amplifier effect indicates that the clearing of forest and grasslands to arable lands explains most of the CO2 amplification. The amplification effect is 50% higher than in a previous analysis by the same authors which considered neither the deforestation of pastures nor the ploughing of grasslands. Such an amplification effect is further examined in sensitivity tests where the net primary productivity is considered independent of the atmospheric CO2. We also show that the land-use changes, which have already occurred in the recent past, have a strong inertia at releasing CO2, and will contribute to about 1/3 of the amplification effect by 2100. These results suggest that there is an additional atmospheric benefit of preserving pristine ecosystems with high turnover times.