The meeting resumed today with the US, Canada, Mexico and Micronesia responding to a number of questions on scientific, legal, financial and technological issues raised by Parties concerning their proposals to amend the Montreal Protocol to phase out HFCs.
After much debate, it was decided to resume the discussion in plenary session tomorrow and consider the establishment of an informal contact group at a later point. The proponents of the phase-out proposals expressed strong disappointment about the informal nature of the contact group – the proposal has been on the table for three years now but has been kicked into the long grass as many times. The informal nature of the contact group means its discussions will not be formally reported in the proceedings of the meeting, just one of the stalling tactics being employed by India, China and others who are opposing any HFC measures under the Montreal Protocol.
During lunch, Greenpeace held a side-event to present a new paper on the benefits of basing policies on a 20-year global warming potential (GWP) measure, rather than the current standard of 100-year GWP. GWP measures the potency of a greenhouse gas over a specific period of time, relative to CO2, which has a GWP of one. So, for example, the GWP of HFC-134a (the most commonly used HFC) is 1,430 – so it is 1,430 times more potent than CO2. The GWP measure is independent of atmospheric concentration – so we’re not saying that HFC-134a is currently causing 1,430 times more global warming than CO2, but it would if it was present in the atmosphere at the same concentration.
The timescale, however, is important because while CO2 has an atmospheric lifetime of several centuries, most HFCs remain in the atmosphere for just 10-20 years. The average lifetime of the HFCs in use today is 21.7 years. This means that the 100-year GWP does not fairly reflect their potency, since it is spread out over 100 years, while in actuality all the damage is done while it is present in the atmosphere, which in the case of HFC-134a is 14 years. The 20-year GWP of HFC-134a is 3,380 – more than double its 100-year GWP.
Why is this important in the context of climate change? In 2009, NASA’s eminent climate scientist, Dr. James Hansen, warned that the “climate is nearing dangerous tipping points… ”. Tipping points are abrupt, non-linear, unpredictable changes – the point of no return where there will be little we can do to prevent catastrophic and irreversible climate change. We don’t know when this will happen but it could be reached within a few decades, so efforts to prevent short-term climate forcing are really important.
The best available prospect for mitigating climate change in the short-term is undoubtedly a phase-out of HFCs under the Montreal Protocol. Using 20-year GWPs shows clearly the massive climate impact of HFCs, and is also highly relevant in the context of the increasing use of so-called ‘moderate’ GWP HFCs, such as HFC-32. Daikin and Panasonic are describing their new HFC-32 air conditioning technology as ‘climate-friendly’, as the GWP of HFC-32 is 675, significantly less than the most commonly used HFC. But over a 20-year period, HFC-32 has a GWP of 2,330 – how can this be climate-friendly?
Clare Perry
