Title: On science informing international policy:  Are emissions of a banned ozone-depleting substance really increasing?

Abstract: Ongoing global-scale measurements of long-lived gases provide unique information for addressing important science and policy-relevant questions.  As a recent example, results suggest that some entities may no longer be adhering to global controls on an ozone-depleting gas agreed to in the Montreal Protocol.  The observational evidence is straightforward: the concentration of CFC-11, the second most abundant ozone-depleting gas, is no longer decreasing as fast as it was 5 years ago, and the slowdown started first in the northern hemisphere.  These changes typically indicate increasing emissions, but this unsettling conclusion seemed highly unlikely, given that production of CFC-11 has reportedly been banned for nearly a decade.  Equally implausible, however, was the alternative conclusion:  that global atmospheric chemistry or dynamics had changed and altered the atmospheric decline of CFC-11.  In this talk I’ll present and update the scientific evidence supporting the assertion that CFC-11 emissions and production have increased in recent years.  I’ll also briefly describe the international response to this news, which is encompassed by a decision adopted earlier this month by the international community tasked with ensuring recovery of the ozone layer, the Parties to the Montreal Protocol.

Speaker Information

Name: 

Steve Montzka

Title: 

Research Chemist

Department: 

NOAA Earth System Research Laboratory

Affiliation: 

Global Monitoring Division

Host: 

Eric Saltzman

Date and Time: 

Friday, November 30, 2018 - 3:00pm

Location: 

The Jenkins Room | Croul Hall 3101