Using Montreal Protocol to
Protect the Climate
Kristen N. Taddonio
U.S. Environmental Protection Agency
Stephen O. Andersen
Co-Chair, Technology & Economic Assessment Panel
The Montreal Protocol is successfully protecting ozone
> The Montreal Protocol has
slowed and reversed the
accumulation of ozone depleting
substances (ODSs) in the
stratosphere.
(Effective stratospheric chlorine is the
weighted sum of chlorine and bromine
gases in the stratosphere.)
UNEP/WMO Ozone Assessment, 2006
Transition from CFC to HCFC or HFC reduced
greenhouse gas emissions ~10 time or more
Example:
Mobile air conditioning sector switched from CFC 12
(GWP 10,900 ODP 1) to HFC-134a (GWP 1,430 ODP 0)
CFC-11 = 1
(ODPs)
UNEP/WMO Ozone Assessment, 2006
CO2 = 1
(GWPs)
The Montreal Protocol has also achieved
extraordinary greenhouse gas reductions
• Tan Line = Global CO2 emissions
• Green line = The CO2-equivalent of the ODS emissions
that would have occurred if Molina and Rowland had not
warned the world about CFCs. Note that the climate
impact would have been greater than global CO2
emissions.
• Blue line = The CO2-equivalent of the ODS emissions that
would have occurred without the Montreal Protocol.
• Black line = The CO2-equivalent of ODS emissions.
Thanks to the Montreal Protocol, this is low.
Montreal Protocol protection
of climate
G. Velders et al., PNAS, 2007
Climate benefits of the Montreal Protocol
• By phasing out ozone-depleting substances, the world has
avoided the equivalent of 135 billion gigatons of carbon
dioxide equivalent between the 1990 and 2010, equivalent to
about 13% of accumulated emissions of CO2 from human
activities.
• This effectively delayed climate change by 7 to 12 years.
• As of 2010, net GWP-weighted emissions reductions from
ODSs are about 11 Gt CO2-eq yr.
• This is 5-6 times the reduction target of the first commitment
period (2008-2012) of the Kyoto Protocol (2 Gt CO2-eq yr).
G. Velders et al., PNAS, 2007
However, larger than
expected growth in use and
emissions of HFCs and HCFCs
threatens to overwhelm
the climate benefits achieved
by the Montreal Protocol.
The large contribution of projected HFC
emissions to future climate forcing
•
•
Based on the most recent trends, HFC emissions in 2050: 5.5–8.8 GtCO2-eq yr
Equivalent to 9–19% of global CO2 emissions, assuming business-as-usual
Velders et al., PNAS (2009)
Article 5 Countries Leading the Way to Use
Montreal Protocol to Further Protect the Climate
• The 2007 HCFC accelerated phaseout
– Proposed by Article 5 countries
– First time developing countries committed to a binding
agreement to reduce greenhouse gas emissions.
• Decision XIX/6 (9.) “To encourage Parties to promote
the selection of alternatives to HCFCs that minimize
environmental impacts, in particular impacts on
climate….” (2007)
• Requests to the TEAP
– Evaluate alternatives to HCFCs
– Environmentally sound management of ODS banks
• Proposals to move HFCs to Montreal Protocol
HCFC Phaseout: Unprecedented Climate Opportunity
CFC, HCFC or HFC Application
Low-GWP Alternatives
Domestic Refrigerators and Freezers
HC-600a
HC-600a & HC-290 blend
Unsaturated HFCs (also called HFOs)
Commercial Refrigeration
HF-600a
HC-290
Carbon dioxide
Large Refrigeration Systems
Ammonia
Carbon dioxide
Hydrocarbons
Air-cooled Air Conditioning & Heat Pumps
HCFC-22 > R410a, R407c
Hydrocarbons in systems with small refrigerant charge
HFOs
Chillers
Ammonia
Hydrocarbons
Carbon Dioxide
HFOs
Mobile Air Conditioning
HFO-1234yf
Carbon Dioxide
Polyurethane (PU) foams
Hydrocarbons (except in spray foam)
CO2 (water), Supercritical CO2
HFO-1234ze
Alternative Insulation (glass fibre, rock fibre)
XPS foams
CO2
Water
TEAP Task Force Decision XX/8 Report, May 2009
Life-Cycle Climate Performance Key to Success
• No alternative is a “one-size-fits all” solution
• Energy efficiency must be taken into account
• Goal: highest LCCP, not just lowest GWP!
– Example: Mobile Air Conditioning
– Alternatives CO2, HFC-152a, HFC-1234yf
• Important for sectors to identify highest
LCCP alternatives as phase-out proceeds
The Montreal Protocol has strong
climate benefits, and can achieve even
greater greenhouse gas reductions.
More Information
• TEAP Reports
– “Environmentally Sound Management of Banks of Ozone-Depleting
Substances” (June 2009)
– “Assessment of Alternative to HCFCs and HFCs” (May 2009)
– Available at: http://ozone.unep.org/teap/Reports/
• Guus J.M. Velders, Stephen O. Andersen, John S. Daniel,
David W. Fahey, and Mack McFarland. “The importance of the
Montreal Protocol in protecting climate.” Proceedings of the
National Academy of Science (PNAS) March 20, 2007 vol. 104
no. 12 4814-4819
• Guus J. M. Velders, David W. Fahey, John S. Daniel, Mack
McFarland, and Stephen O. Andersen. “The large contribution
of projected HFC emissions to future climate forcing” PNAS
July 7, 2009 vol. 106 no. 27 10949-10954
• Available on-line at: www.pnas.org
More Information
Kristen N. Taddonio
[email protected]
Stephen O. Andersen
[email protected]