To reach EU’s carbon neutrality target by 2050, emission reductions in the land-use sector are needed. Agricultural peatlands attribute for half of the greenhouse gas emissions of cropland in both in EU and Finland. High greenhouse gas emissions from agricultural peatlands are primarily caused by CO emissions following aerobic peat decomposition due to deep drainage, and studies have shown that raising water-table has potential to slow down the decomposition process. Here we studied the emission reduction potential and cost of implementing controlled drainage, paludiculture, peatland restoration and afforestation to current land use on agricultural peatlands in Finland. We created three scenarios with increasing amount of wet field use on cultivated organic soils and estimated their effects on national greenhouse gas emissions and farmers’ income. The yearly emission reduction ranged from 0.3 to 5.0 Mt CO equivalents in the different scenarios compared to the current state in Finland. Emission reductive land use had a negative impact on the farmers income, which should be compensated. Assuming the government compensates the lost income for the farmers, the cost of emission reduction ranged from −4 to 45 € per ton of CO equivalents. Rewetting provided the most emission reduction per area and was the most cost effective. We conclude that substantial emission reduction is attainable by rewetting agricultural peatlands. The cost of emission reduction is inexpensive compared to average carbon price in European Union emission trading system, or to the costs of technical carbon capture and storage in Finland.

中文翻译：

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农业泥炭地的再湿润可以在国家层面上实现具有成本效益的温室气体减排


为了到 2050 年实现欧盟的碳中和目标，需要减少土地利用部门的排放。在欧盟和芬兰，农业泥炭地占农田温室气体排放量的一半。农业泥炭地的高温室气体排放主要是由于深层排水导致泥炭好氧分解后的二氧化碳排放造成的，研究表明，提高地下水位有可能减缓分解过程。在这里，我们研究了芬兰农业泥炭地当前土地利用实施控制排水、沼泽耕作、泥炭地恢复和造林的减排潜力和成本。我们创建了三种情景，即耕作有机土壤的湿地使用量不断增加，并估计了它们对国家温室气体排放和农民收入的影响。与芬兰目前的情况相比，在不同情景下，每年的减排量为 0.3 至 5.0 公吨二氧化碳当量。减排土地利用对农民收入产生了负面影响，应予以补偿。假设政府补偿农民的收入损失，每吨二氧化碳当量的减排成本为-4至45欧元。再润湿可以最大程度地减少单位面积的排放，并且最具成本效益。我们的结论是，通过再湿润农业泥炭地可以大幅减少排放。与欧盟排放交易体系的平均碳价格或芬兰的技术碳捕获和储存成本相比，减排成本并不昂贵。