Large changes in Great Britain's vegetation and agricultural land-use predicted under unmitigated climate change
Large changes in Great Britain's vegetation and agricultural land-use predicted under unmitigated climate change
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DOI：
10.1088/1748-9326/ab492b
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发表时间：
2019-11-01
影响因子：
6.7
通讯作者：
Lenton, Timothy M.
中科院分区：
文献类型：
--
作者：
Ritchie, Paul D. L.;Harper, Anna B.;Lenton, Timothy M.
气候变化对包括农业生产在内的植被的影响一直是许多研究的焦点。气候变化预计将在全球各地产生异质影响，而英国土地利用的多样性为评估气候变化影响和影响的方法提供了一个独特的机会。GB是一个相对凉爽和潮湿的国家，因此，预计未来生长季节的温暖和普遍干燥的条件将增加可耕地产量。在这里，我们使用最先进的、公里尺度的气候变化情景来驱动陆地表面模型（JULES；联合英国土地环境模拟器）和计量农业土地利用模型（ECO-AG）。在不减缓气候变化的情况下，到本世纪末，预计英国的生长季节将平均变暖0.5摄氏度，变干140毫米。预计大气二氧化碳水平的上升将抵消气候变化对JULES植被生产力的总体负面影响。在降水充足的情况下，气候变暖有利于高价值的耕地生产，而不是草地农业，导致ECO-AG预测的耕地生产向西扩张。然而，东部和东南部的干旱，在没有任何二氧化碳施肥效应的情况下，已经严重到足以导致从耕地到草地农业的预测逆转。灌溉，如果实施，可以保持这片土地的可耕地生产。然而，在许多地方，预测的灌溉需求（每个生长季节）约为200毫米，与年预测径流相当，可能需要在季节之间和/或在全国范围内进行大规模的水再分配。在预测气候变化对GB植被的影响，特别是农业土地利用决策时，二氧化碳施肥效应的强度是一个至关重要的不确定性。
The impact of climate change on vegetation including agricultural production has been the focus of many studies. Climate change is expected to have heterogeneous effects across locations globally, and the diversity of land uses characterising Great Britain (GB) presents a unique opportunity to test methods for assessing climate change effects and impacts. GB is a relatively cool and damp country, hence, the warmer and generally drier growing season conditions projected for the future are expected to increase arable production. Here we use state-of-the-art, kilometre-scale climate change scenarios to drive a land surface model (JULES; Joint UK Land Environment Simulator) and an ECOnometric AGricultural land use model (ECO-AG). Under unmitigated climate change, by the end of the century, the growing season in GB is projected to get >5 degrees C warmer and 140 mm drier on average. Rising levels of atmospheric CO2 are predicted to counteract the generally negative impacts of climate change on vegetation productivity in JULES. Given sufficient precipitation, warming favours higher value arable production over grassland agriculture, causing a predicted westward expansion of arable farming in ECO-AG. However, drying in the East and Southeast, without any CO2 fertilisation effect, is severe enough to cause a predicted reversion from arable to grassland farming. Irrigation, if implemented, could maintain this land in arable production. However, the predicted irrigation demand of similar to 200 mm (per growing season) in many locations is comparable to annual predicted runoff, potentially demanding large-scale redistribution of water between seasons and/or across the country. The strength of the CO2 fertilisation effect emerges as a crucial uncertainty in projecting the impact of climate change on GB vegetation, especially farming land-use decisions.