Journal Article
Atmospheric Chemistry and Physics, vol. 19, iss. 4, pp. 2405-2420, 2019
Authors
Yang Yang, Steven J. Smith, Hailong Wang, Catrin M. Mills, Philip J. Rasch
Abstract
Abstract. Black carbon (BC) particles exert a potentially large warming influence on
the Earth system. Reductions in BC emissions have attracted attention as a
possible means to moderate near-term temperature changes. For the first time,
we evaluate regional climate responses, nonlinearity, and short-term
transient responses to BC emission perturbations in the Arctic, midlatitudes,
and globally based on a comprehensive set of emission-driven experiments
using the Community Earth System Model (CESM). Surface temperature responses
to BC emissions are complex, with surface warming over land from midlatitude
BC perturbations partially offset by ocean cooling. Climate responses do not
scale linearly with emissions. While stronger BC emission perturbations have
a higher burden efficiency, their temperature sensitivity is lower. BC
impacts temperature much faster than greenhouse gas forcing, with transient
temperature responses in the Arctic and midlatitudes approaching a
quasi-equilibrium state with a timescale of 2–3 years. We find large
variability in BC-induced climate changes due to background model noise. As a
result, removing present-day BC emissions results in discernible surface
temperature changes for only limited regions of the globe. In order to better
understand the climatic impacts of BC emissions, both the drivers of
nonlinear responses and response variability need to be assessed across
climate models.
