Figure 2-8: Estimates of northern mid-latitude total
ozone column changes (%) from NOx emission in the troposphere and stratosphere
and aerosol emissions in the stratosphere from present subsonic aviation.
The height of the rectangular bars indicates the mid-range estimate; the error
bars represent an estimate of the two-thirds probability uncertainty range
(i.e., a 67% chance that the true value falls within this range) as determined
from either the dispersion among global model results or from consideration
of process understanding. Independent of the specified uncertainty range,
we judge the state of scientific understanding regarding aviation's NOx and
particle effects to be fair and poor, respectively. This evaluation is based
on the level of consensus in the scientific literature and the amount of evidence
available to support the estimates and their uncertainties.