Beware rushed solutions to problems exaggerated in the media. Hydrofluorocarbons (HFCs) were once touted as the solution for ozone-depleting hydrochlorofluorocarbons (HCFCs) since they don't have the impact on the ozone layer that HCFCs do, even though they allowed for the phaseout of chlorofluorocarbons(CFCs) which replaced ammonia in refrigeration and spray cans.
Did you get all that?
After recognizing the climate impacts of HCFCs in early 2007, the Montreal Protocol Parties agreed to accelerate the phaseout of HCFCs in order to avoid up to 16 billion tonnes of CO2-eq by 2040.
But now it turns out we need to change again and create some new climate and ozone-friendly substitute for HFCs, else HFC emissions will cancel out the climate benefits of what they were created to fix.
Some HFCs can be up to 11,000 times more potent than CO2 in warming the atmosphere. Such a dramatic increase in HFCs will threaten efforts to curb climate change unless a production and consumption phase-down schedule is established in both developed and developing countries.
The accelerated phase-out decision and other new developments mean that previous scenarios significantly underestimate the growth of HFC use and emissions. By 2050, developing country HFC emissions are estimated to be 800% greater than in developed countries.
The report notes however, that if a global consumption cap followed by 4% annual reductions in consumptions is implemented, radiative forcing would peak near 2040 and begin to decline, resulting in mitigation of 70-113 GtCO2-eq. through 2050.
Because HFCs have a much shorter atmospheric lifetime than CO2, taking aggressive action now could be the key to avoiding tipping points for abrupt climate change, which threatens a myriad of vulnerable nations, including island and coastal countries in danger of disappearing with rising sea levels.
One possible solution for quick and successful mitigation of HFCs is to regulate them under the Montreal Protocol, which The Federated States of Micronesia (FSM) and Mauritius called for in April of this year with the submission of a formal proposal to the Protocol Secretariat. The U.S. did not submit a proposal, but is still considering such a strategy on HFCs.
The Montreal Protocol Parties will host a dialogue next month in Geneva where representatives from both the Montreal Protocol and the UNFCCC will discuss the possibilities for collaboration on this issue.
Dr. Guus Velders of The Netherlands Environmental Assessment Agency and lead author of the article published in the Proceedings of the National Academy of Sciences, stated, “Our team of scientists calculates that HFCs present a significant threat to the world’s efforts to stabilize climate emissions. Because of the projected growth of these climate warming chemicals, they could represent up to 45% of total global CO2 emissions by 2050 under a scenario that stabilizes CO2 emissions at 450 ppm. Preventing strong growth in HFC use is a important climate mitigation option the world has now. Our 2007 PNAS paper on the climate benefits of the Montreal Protocol shows how powerful the stratospheric ozone treaty has been in reducing CFCs, HCFCs, and other chemicals similar to HFCs.”
Citation: Guus J. M. Veldersa, David W. Fahey, John S. Daniel, Mack McFarland and Stephen O. Andersen, 'The large contribution of projected HFC emissions to future climate forcing', Published online before print June 22, 2009, doi: 10.1073/pnas.0902817106