Chemist and atmospheric scientist, A.R. Ravishankara, is part of team suggesting new steps in ending ozone layer depletion

The Montreal Protocol, finalized in 1987 and now ratified by 197 countries, has been healing the global ozone layer by phasing out the production of numerous ozone-depleting substances, avoiding more global warming than any other climate treaty to date.

However, research is showing that the success of the protocol is being hindered, and it may be time to make some changes for its continued success.

A.R. Ravishankara, University Distinguished Professor of Chemistry and Atmospheric Science, Colorado State University

In a paper published in Nature Communications, A.R. Ravishankara, a CSU University Distinguished Professor in the Departments of Chemistry and Atmospheric Science, along with collaborators Professor Susan Solomon from the Massachusetts Institute of Technology and Professor Joseph Alcamo from the University of Sussex, discussed the unexpected emissions of chlorofluorocarbons (CFCs), carbon tetrachloride (CCl4), and hydrofluorocarbons (HFC) related to air conditioning and cooling that are not where they should be as expected by the Montreal Protocol. The paper also exposed possible leakages from feedstocks and other industrial processes that are not currently controlled in the Montreal Protocol.

“There are a few things that need to happen soon,” Ravishankara said. “First, the Kigali Amendment needs to be ratified by all countries and the greenhouse gas, HFC23, needs to be curtailed. Second, we need to prevent what I call ‘rogue emissions,’ which are emissions that shouldn’t be there, but they are. That requires a lot of scientific input to actually know such emissions are happening and to pinpoint where emissions are coming from so the countries involved can take the necessary action.”

Graphic by A.R. Ravishankara addressing what could be should these unexpected emissions be eliminated.

Working on the protocol

Ravishankara has been involved in the Montreal Protocol even before it began, working on the assessments that helped the international climate agreement come about. From 2010 to 2014, he co-chaired the Quadrennial Ozone Layer Assessment under the World Meteorological Organization and the United Nations Environment Programme (UNEP). With his extensive research on HFCs, he was also a major player in the Protocol’s 2016 Kigali Amendment, designed to reduce the use of HFCs. Ravishankara continues to work on these assessments and is currently the chair of Vienna Convention Trust Fund of UNEP, which oversees the use of funds to foster ozone layer science.

For changes to happen, agreement is required from almost all the parties involved. Ravishankara’s paper offers another piece for their consideration. Read the entire paper in Nature Communications.