アイテム詳細

要旨

The Brewer-Dobson circulation (BDC), which is an important driver of the stratosphere-troposphere exchange, is expected to accelerate with climate change. One particular consequence of this acceleration is the enhanced transport of nitrous oxide (N2O) from its sources at the Earth's surface towards its main sink region in the stratosphere thus inducing a reduction in its lifetime. N2O is a potent greenhouse gas and the most relevant currently emitted ozone depleting substance. Here we examine the implications of a reduced N2O lifetime in the context of climate change. We find a decrease in its global warming potential (GWP) and, due to a decline in the atmospheric N2O burden, also a reduction in its total radiative forcing. From the idealized transient global warming simulation we can identify linear regressions for N2O sink, lifetime and GWP with temperature rise. Our findings are thus not restricted to a particular scenario.