资源环境科技发展态势分析平台

Ozone depletion potentials (ODPs) are an important metric in national and international policy for evaluating the relative importance of different gases to affecting stratospheric ozone. In evaluating the ODPs of iodotrifluoromethane (CF3I) and methyl iodide (CH3I) using the recently updated understanding of atmospheric iodine chemistry, only minor ozone loss would be expected to occur in the stratosphere from the very short-lived (6 days) CF3I, with slightly larger destruction of stratospheric ozone from CH3I (12 days). In addition, most of the ozone destruction would likely occur in the lower troposphere over continental surfaces, reducing anthropogenic ozone pollution. The traditional ODP concept uses total column ozone change, but this is not an accurate representation of potential future use of very short-lived substances (VSLSs) on the abundance of stratospheric ozone. A new metric, Stratospheric ODP (or SODP), is defined that only accounts for stratospheric ozone loss, providing a useful additional tool for policy considerations of VSLSs on stratospheric ozone.

Plain Language Summary CF3I and CH3I are two very short-lived substances (VSLSs) with potential commercial applications. This study updates their potential impact on atmospheric ozone based on recent advances in the understanding of atmospheric iodine chemistry. It also reconsiders the concept of ozone depletion potentials (ODPs) for such short-lived chemicals. Analyses of potential effects of ozone for some of these chemicals show very small effects on the total ozone column and almost all ozone loss occurring in the lower troposphere, where these VSLSs would essentially reduce the overall human-produced ozone pollution. A new metric is introduced to help clarify the effects of these very short-lived chemicals on the global atmosphere in policy considerations.