Extreme weather events exacerbate nitrous oxide emissions from soil (Extreme-N2O)

农业温室气体排放的准确估计是国家土地利用政策和后续目标的基础，例如，最近英国的目标是到2050年实现净零碳排放。然而，利用大气浓度对陆地氧化亚氮（N2O）来源进行的模拟显示，英国N2O排放的自下而上的温室气体清单要么缺少一个主要来源，要么低估了一个来源。极端天气频率的增加，例如长期干旱和洪水，破坏了土壤碳、氮和水文循环，影响了土壤在恢复通气状态（洪水后）和水分状态（干旱后）时产生和排放的温室气体。在极端天气事件期间和之后，土壤中N2O排放的增加可能是造成这种“缺失”的N2O的原因。虽然对土壤中N2O排放的大小已经有了很多了解，但用于获得用于国家温室气体清单的改进的N2O排放因子的大多数实验都是在没有极端天气的情况下进行的。极端-N2O项目将测试以下假设：1)极端天气事件加剧了土壤中N2O的产生和排放；2)极端天气事件导致了N2O的“缺失”。

Accurate estimates of agricultural greenhouse gas emissions underpin national land use policy and subsequent targets, e.g. the recent UK target for net zero carbon emissions by 2050. However, modelling of terrestrial sources of nitrous oxide (N2O) using atmospheric concentrations reveals that the bottom up greenhouse gas inventory for UK N2O emissions is either missing a major source(s) or underestimating a source(s). Increasing frequencies of extreme weather, e.g. prolonged drought and flooding, disrupt soil carbon, nitrogen and hydrological cycles, affecting the production and emission of greenhouse gases from soils as they recover their aeration status (post flooding) and moisture status (post drought). Increased N2O emission from soils during and post extreme weather events may be responsible for this 'missing' N2O. Whilst much is already known about the magnitude of N2O emissions from soil, most experiments used to derive improved N2O emission factors for use in in national greenhouse gas inventories have been conducted in the absence of extreme weather. The Extreme-N2O project will test the hypotheses that i) extreme weather events exacerbate N2O production and emission from soil, and ii) extreme weather events contribute to the 'missing' N2O.