Desert dust exerts a substantial longwave radiative forcing missing from climate models
Links to Files
Permanent Link
Author/Creator ORCID
Date
Type of Work
Department
Program
Citation of Original Publication
Rights
This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
Public Domain
Public Domain
Subjects
Abstract
Historical increases in desert dust have affected climate by perturbing Earth’s energy balance, including through interactions with longwave radiation that remain poorly quantified. Here, we use a data-driven analytical model to estimate the global dust longwave direct radiative effect (DRE). Our results align with observational estimates of longwave radiative effects, constraining the present-day global longwave DRE to +0.25 ± 0.06 Wm⁻² (90% confidence interval). Climate models underestimate the longwave DRE by approximately a factor of two because they underestimate super coarse dust and neglect dust scattering of longwave radiation. We also show that increased dust since preindustrial times generated a positive longwave direct radiative forcing peaking at +0.14 ± 0.07 Wm⁻² in the 1980s, modestly enhancing greenhouse warming. Because this warming is largely missing from current climate models, incorporating it could reduce biases in net aerosol forcing, refine climate sensitivity estimates, and improve projections of future climate change.