Journal Article

Uncertainties in climate assessment for the case of aviation NO

Prather, Michael J, Holmes, Christopher D, Tang, Qi

2011

Overview

Nitrogen oxides emitted from aircraft engines alter the chemistry of the atmosphere, perturbing the greenhouse gases methane (CH₄) and ozone (O₃). We quantify uncertainties in radiative forcing (RF) due to short-lived increases in O₃, long-lived decreases in CH₄ and O₃, and their net effect, using the ensemble of published models and a factor decomposition of each forcing. The decomposition captures major features of the ensemble, and also shows which processes drive the total uncertainty in several climate metrics. Aviation-specific factors drive most of the uncertainty for the short-lived O₃ and long-lived CH₄ RFs, but a nonaviation factor dominates for long-lived O₃. The model ensemble shows strong anticorrelation between the short-lived and long-lived RF perturbations (R² = 0.87). Uncertainty in the net RF is highly sensitive to this correlation. We reproduce the correlation and ensemble spread in one model, showing that processes controlling the background tropospheric abundance of nitrogen oxides are likely responsible for the modeling uncertainty in climate impacts from aviation.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: Aircraft / Airplane engines / Atmospheric chemistry / Atmospheric models / Aviation / climate / Climate change / Climate models / Correlation analysis / Decomposition / Environmental assessment / Greenhouse gases / International environmental cooperation / Methane / Modeling / Nitric oxide / Nitrogen oxides / Ozone / Photochemicals / Physical Sciences / Pollutant emissions / Radiative forcing / Troposphere / uncertainty