Mitigation of Climate Change
IPCC Working Group III contribution
to the Fourth Assessment Report
Bert Metz
Netherlands Environmental Assessment Agency
Co-chair IPCC WG III
Green Week, Brussels, June 12, 2007
The key question: can “dangerous
anthropogenic climate change” be avoided?
Equilibrium global mean temperature increase over preindustrial(°C)
GHG concentration stabilization level (ppmv CO2-eq) Equilibrium global mean temperature increase over preindustrial(°C)
GHG concentration stabilization level (ppmv CO2-eq)
•EU interpretation: keep global mean temperature
increase at less than 2 degrees above pre-industrial level
The lower the stabilisation level the earlier
global emissions have to go down
-5 0 5 10 15 20 25 30 35
2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100
Wold CO2 Emissions (GtC)
E: 850-1130 ppm CO2-eq D: 710-850 ppm CO2-eq C: 590-710 ppm CO2-eq B: 535-590 ppm CO2-eq A2: 490-535 ppm CO2-eq A1: 445-490 ppm CO2-eq
Stabilization targets:
Post-SRES (max)
Post-SRES (min)
-5 0 5 10 15 20 25 30 35
2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100
Wold CO2 Emissions (GtC)
E: 850-1130 ppm CO2-eq D: 710-850 ppm CO2-eq C: 590-710 ppm CO2-eq B: 535-590 ppm CO2-eq A2: 490-535 ppm CO2-eq A1: 445-490 ppm CO2-eq
Stabilization targets:
Post-SRES (max)
Post-SRES (min)
Multigas and CO2 only studies combined
Equilibrium global mean temperature increase over preindustrial(°C)
GHG concentration stabilization level (ppmv CO2-eq) Equilibrium global mean temperature increase over preindustrial(°C)
GHG concentration stabilization level (ppmv CO2-eq)
Mitigation efforts over the next two to three decades
will have a large impact on opportunities to achieve
lower stabilization levels
Stababilization level (ppm CO2-eq)
Global Mean temperature
increase at equilibrium
(ºC)
Year global CO2 needs
to peak
Year global CO2 emissions
back at 2000 level
Reduction in 2050 global CO2
emissions compared to
2000
445 – 490 2.0 – 2.4 2000 - 2015 2000- 2030
2000- 2040 2020- 2060 2050- 2100
-85 to -50
490 – 535 2.4 – 2.8 2000 - 2020 -60 to -30
535 – 590 2.8 – 3.2 2010 - 2030 -30 to +5
590 – 710 3.2 – 4.0 2020 - 2060 +10 to +60
710 – 855 4.0 – 4.9 2050 - 2080 +25 to +85
855 – 1130 4.9 – 6.1 2060 - 2090 +90 to +140
How difficult is this?
• Current emission trends
• Technologies to reduce emissions
• [Costs]
• Policies
• International agreements
Between 1970 and 2004 global greenhouse gas
emissions have increased by 70 %
Total GHG emissions
0 5 10 15 20 25 30 35 40 45 50 55 60
1970 1980 1990 2000 2004
GtCO2-eq/yr
Carbon dioxide is the
largest contributor
Higher growth rate
of CO2 from fossil
fuel since 2000
With current climate change mitigation
policies and related sustainable development
practices, global GHG emissions will
continue to grow over the next few decades
• IPCC SRES scenarios:
25-90 %
increase of GHG
emissions
in 2030 relative to
2000
020 40 60 80 100 120
2000 A1F1 A2 A1B A1T B1 B2
2030 GtCO2eq/yr
F-Gases N2O CH4 CO2
How can emissions be reduced?
Sector Key mitigation technologies and practices currently commercially available. (Selected)
Key mitigation technologies and practices projected to be
commercialized before 2030. (Selected) Energy
Supply
efficiency; fuel switching; nuclear power; renewable (hydropower, solar, wind, geothermal and bioenergy); combined heat and power; early applications of CO2 Capture and Storage (CCS)
CCS for gas, biomass and coal-fired electricity generating facilities;
advanced nuclear power;
advanced renewables (tidal and wave energy, concentrating solar, solar PV)
Potential share of global electricity supply in 2030 for carbon prices <
US$50/tCO2eq:
•Renewable energy: 30-35% (now 18%)
•Nuclear: 18% (now 16%)
•CCS: 9% of coal powered capacity
How can emissions be reduced?
Sector (Selected) Key mitigation
technologies and practices
currently commercially
available.
Key mitigation technologies and
practices projected to be
commercialized before 2030.
(Selected)
Transport More fuel efficient vehicles;
hybrid vehicles; biofuels;
modal shifts from road
transport to rail and public
transport systems; cycling,
walking; land-use planning
Second generation biofuels; higher
efficiency aircraft; advanced
electric and hybrid vehicles with
more powerful and reliable
batteries
Mitigation potential in the transport sector till 2030
• Goods transport, public
transport: not quantified
• Vehicle efficiency: net benefits
(many cases), but big barriers
• Aviation: efficiency, but not
offsetting growth
• Biofuel potential :
– Depends on production
pathway, vehicle efficiency, oil and carbon prices
– 3% of global transport energy in 2030; 5-10% , if cellulose biomass is commercialised – Watch out for: local land and
water availability, competition with food
All sectors and regions have the
potential to contribute (end-use based)
Note: estimates do not include non-technical options, such as lifestyle changes.
Global economic potential sufficient to offset
2030 projected emissions growth or bring
emissions below current levels
Stabilisation
level Global Mean temp.
increase at equilibrium
Estimated CO2 reduction needed by 2030 compared to baseline
Annex-I 2030 CO2 mitigation potential (bottom-up)
Global 2030 CO2 mitigation potential (bottom-up)
(ppm CO2-eq) (ºC) (GtCO2eq/yr (GtCO2eq/yr) (GtCO2eq/yr)
<US$50/t <US$100/t <US$50/t <US$100/t 12-25
12-25
12-25
12-25
6-9 15-30
6-9
6-9
6-9
15-30
15-30
15-30 7-11
7-11
7-11
7-11
445 – 490 2.0 – 2.4 20-34
490 – 535 2.4 – 2.8 15-26
535 – 590 2.8 – 3.2 11-24
590 – 710 3.2 – 4.0 4- 16
Technology in the long term
• The range of stabilization levels can be achieved by
– deployment of a portfolio of technologies that are currently available and – those that are expected to be commercialised in coming decades.
• This assumes that appropriate and effective incentives are in place for
development, acquisition, deployment and diffusion of technologies
and for addressing related barriers
Climate policy can have positive or
negative effects on other aspects of SD
Non-climate policies can influence
GHG emissions as much as specific
climate policies
Two-way Relationship Between Climate
Change and Sustainable Development
Climate
change
mitigation
Sustainable
development
Co-benefits of mitigation
• Near–term health benefits from reduced air
pollution may offset a substantial fraction of
mitigation costs
• Mitigation can also be positive for: energy
security, balance of trade improvement,
provision of modern energy services to rural
areas, sustainable agriculture and employment
Non-climate policies can influence GHG
emissions as much as specific climate policies
Sectors Non-climate policies -- Candidates for integrating climate concerns
Possible influence (% of global emissions) Macro-economy Taxes, subsidies, other fiscal policies All GHG emissions
(100%) Electricity Diversification to low-carbon sources,
demand management, limit distribution losses
Electricity sector emissions (20 %)
Oil-imports Diversification energy sources/decrease intensity -> enhance energy security
GHGs from oil product imports (20 %)
Insurance (buildings, infrastructure)
Differentiated premiums, liability
insurance exclusion, improved conditions for green products
GHG emissions buildings, transport (20%)
Bank lending Sector/ country strategies, avoid lock-in into old technologies in developing countries
Notably development projects (25%)
Rural energy Policies promoting LPG, kerosene and electricity for cooking
Extra emissions over biomass (<2 %)
