2015 was the warmest year since modern record keeping began, image courtesy NASA (colours indicate temperature anomalies)
197 nations agreed to drastically reduce their use of hydrofluorocarbons (HFCs) at the 28th Meeting of the Parties to the Montreal Protocol in October.
“This is good news. It shows that you can get things accomplished with the right combination of scientific input and recognition of the economic realities,” says Head of Department Professor John Pyle, who is one of four international co-chairs of the Montreal Protocol Scientific Assessment Panel.
HFCs are extremely powerful greenhouse gases used mainly in air conditioners and refrigeration. They were developed in the 1990s to replace the ozone depleting substances being phased out under the Montreal Protocol, as they do not damage ozone. However, HFCs have been identified as major contributors to global warming, and were listed among the seven greenhouse gases targeted by the UN Framework Convention on Climate Change. In 2015, member nations agreed that HFCs could be brought within the remit of the Montreal Protocol, leading the way to this historic agreement to phase out their use.
“The compelling scientific evidence, along with compromise and economic support were all essential to reaching this agreement,” says John. For example, High Ambient Temperature countries rely more heavily on using HFCs in air conditioning units, and developing countries do not have the financial resources to switch to safer alternatives. The compromise negotiated allows a slower phase-out of HFCs for some countries, who will also be helped to make the transition by a multi-lateral fund.
It is thought the elimination of HFCs by 2050 will prevent a 0.5 degree Celsius rise in global temperatures by the end of this century, vital for reaching the Paris Agreement target of keeping global temperature rise to below two degrees Celsius.
The Montreal Protocol on Substances that Deplete the Ozone Layer came into force in 1987 in response to scientific evidence that human-induced depletion of the ozone layer was occurring. It is an outstanding example of how nations can successfully cooperate to prevent damage to the environment from human-induced atmospheric emissions.
“The original Montreal Protocol started out modestly, calling for limited regulation on the emission of CFCs,” says John. “As our knowledge of how chemical emissions affect the earth’s atmosphere has increased, the Protocol has played an increasingly key role in regulating harmful emissions. As co-chair of the Scientific Assessment Panel, I’ve been able to ensure that the research we are doing in Cambridge and other excellent research from around the world is effectively communicated to the policymakers.”