Temporary carbon storage can mitigate slow-responding climate changes

Abstract

Abstract Carbon removal and storage is central to many net-zero commitments, yet its durability, particularly for nature-based methods, is uncertain due to disturbance risks. Previous work shows that carbon storage-years (the time-integrated quantity of carbon storage) are proportional to time-integrated avoided warming, which in turn causes avoided changes in slow-responding climate variables. Here, we show that temporary carbon storage results in avoided changes in inertial climate variables. Avoided changes in 2100 are proportional to carbon storage-years across a range of storage amounts and emissions scenarios for permafrost carbon, ocean carbon, Atlantic meridional overturning circulation, ocean temperature, and thermosteric sea-level rise. By 2300, proportionality persists in some variables, notably sea-level rise, ocean temperature, and ocean carbon. Temporary storage therefore has climate benefits that extend beyond the duration of the storage, with some persistence of benefits even on multi-century timescales. We find that these climate benefits are greatest when temporary storage is paired with ambitious mitigation.