Box SPM-3 (WGIII) Assumptions in studies on mitigation portfolios and macro-economic costs
Studies on mitigation portfolios and macro-economic costs assessed in this report are based on top-down modelling. Most models use a global least cost approach to mitigation portfolios and with universal emissions trading, assuming transparent markets, no transaction cost, and thus perfect implementation of mitigation measures throughout the 21st century. Costs are given for a specific point in time.
Global modelled costs will increase if some regions, sectors (e.g. land-use), options or gases are excluded. Global modelled costs will decrease with lower baselines, use of revenues from carbon taxes and auctioned permits, and if induced technological learning is included. These models do not consider climate benefits and generally also co-benefits of mitigation measures, or equity issues.
Source & © IPCC Climate Change 2007: 
"Mitigation, Summary for Policymakers" (2007), p8
Related publication:
Other Figures & Tables on this publication:
Figure SPM-1. (WGI) Changes in Greenhouse Gases from Ice-core and Modern Data
Figure SPM-2. (WGI) Radiative Forcing Components
Figure SPM-3. (WGI) Changes in Temperatures, Sea Level and Snow Cover between 1850 and 2010
Figure SPM-4. (WGI) Global and Continental Temperature Change
Figure SPM-5. (WGI) Multi-model Averages and Assessed Ranges for Surface Warming
Figure SPM-6. (WGI) AOGCM Projections of Surface Temperatures
Figure SPM-7. (WGI) Projected Patterns of Precipitation Changes
Figure SPM-1. (WGII) Changes in physical and biological systems and surface temperature 1970-2004
Figure SPM-2. (WGII) Key impacts as a function of increasing global average temperature change
Figure SPM-1. (WGIII) Emissions of different greenhouse gases 1970-2004
Figure SPM-2. (WGIII) Relative global development of indicators of income, energy supply, CO2 emissions and population for 1970 to 2004
Figure SPM-3a. (WGIII) Distribution of regional per capita greenhouse gas emissions
Figure SPM-3b. (WGIII) Distribution of regional greenhouse gas emissions per unit of income
Figure SPM-4. (WGIII) Global greenhouse gas emissions for 2000, 2030 and 2100
Figure SPM-5a/5b. (WGIII) Estimated global economic mitigation potential
Figure SPM-6. (WGIII) Estimated economic mitigation potential in 2030 as a function of carbon price
Figure SPM-7. (WGIII) Emissions pathways of mitigation scenarios for alternative categories of stabilization levels
Figure SPM-8. (WGIII) Relationship between stabilization scenario categories and equilibrium global mean temperature change
Figure SPM-9. (WGIII) Cumulative emissions reductions for alternative mitigation measures for 2000 to 2030 (left-hand panel) and for 2000-2100 (right-hand panel)
Global greenhouse gas emissions 1970-2004
Table SPM-1. (WGI) Observed rate of sea level rise and estimated contributions from different sources.
Table SPM-2. (WGI) Recent trends, assessment of human influence on the trend, and projections for extreme weather events for
which there is an observed late 20th century trend.
Table SPM-3. (WGI) Projected globally averaged surface warming and sea level rise at the end of the 21st century.
Table SPM-1. (WGII) Examples of possible impacts of climate change due to changes in extreme weather and climate events
based on projections to the
mid- to late 21st century. These do not take into account any changes or developments in adaptive capacity. Examples of all entries are to be found
in chapters in the full Assessment (see source at top of columns). The first two columns of the table (shaded yellow) are taken directly from the
Working Group I Fourth Assessment (Table SPM-2). The likelihood estimates in Column 2 relate to the phenomena listed in Column 1.
Table SPM-4. (WGIII) Estimated global macro-economic costs in 2030a for least-cost trajectories towards different long-term stabilization levels.b,c
Table SPM-5. (WGIII) Characteristics of post-TAR stabilization scenarios
[Table TS 2, 3.10]a
Table SPM-6. (WGIII) Estimated global macro-economic costs in 2050 relative to the baseline for
least-cost trajectories towards different long-term stabilization targetsa
[3.3, 13.3]
Table SPM-7. (WGIII) Selected sectoral policies, measures and instruments that have shown to be
environmentally effective in the respective sector in at least a number of national cases.
Table SPM-1. (WGIII) Global economic mitigation potential in 2030 estimated from bottom-up studies.
Table SPM-2. (WGIII) Global economic mitigation potential in 2030 estimated from top-down studies.
Table SPM-3. (WGIII)
Key mitigation technologies and practices by sector. Sectors and technologies are listed in no particular order. Non-technological practices, such as lifestyle changes, which are cross-cutting, are not included in this table (but are addressed in paragraph 7 in this SPM).
Figure SPM-2. (WGII) Key impacts as a function of increasing global average temperature change
Figure SPM-6. (WGIII) Estimated economic mitigation potential in 2030 as a function of carbon price
Likelihood
The Emission Scenarios of the IPCC Special Report on Emission Scenarios (SRES)
Box SPM-2 (WGIII) Mitigation potential and analytical approaches
Box SPM-3 (WGIII) Assumptions in studies on mitigation portfolios and macro-economic costs
Box SPM-4 (WGIII) Modelling induced technological change
Parties & Observers of the UNFCCC
