IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group III: Mitigation of Climate Change

E. Policies, measures and instruments to mitigate climate change

22. A wide variety of national policies and instruments are available to governments to create the incentives for mitigation action. Their applicability depends on national circumstances and an understanding of their interactions, but experience from implementation in various countries and sectors shows there are advantages and disadvantages for any given instrument (high agreement, much evidence).

  • Four main criteria are used to evaluate policies and instruments: environmental effectiveness, cost effectiveness, distributional effects, including equity, and institutional feasibility [13.2].
  • All instruments can be designed well or poorly, and be stringent or lax. In addition, monitoring to improve implementation is an important issue for all instruments. General findings about the performance of policies are: [7.9, 12.2,13.2]
  • Integrating climate policies in broader development policies makes implementation and overcoming barriers easier.
  • Regulations and standards generally provide some certainty about emission levels. They may be preferable to other instruments when information or other barriers prevent producers and consumers from responding to price signals. However, they may not induce innovations and more advanced technologies.
  • stabilization.
  • Some corporations, local and regional authorities, NGOs and civil groups are adopting a wide variety of voluntary actions. These voluntary actions may limit GHG emissions, stimulate innovative policies, and encourage the deployment of new technologies. On their own, they generally have limited impact on the national or regional level emissions [13.4].
  • Lessons learned from specific sector application of national policies and instruments are shown in Table SPM.7.

Table SPM.7: 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.

Sector Policiesa), measures and instruments shown to be environmentally effective Key constraints or opportunities 

Energy supply [4.5]

Reduction of fossil fuel subsidies Resistance by vested interests may make them difficult to implement 
Taxes or carbon charges on fossil fuels 
Feed-in tariffs for renewable energy technologies May be appropriate to create markets for low emissions technologies 
Renewable energy obligations 
Producer subsidies 

Transport [5.5]

Mandatory fuel economy, biofuel blending and CO2 standards for road transport Partial coverage of vehicle fleet may limit effectiveness 
Taxes on vehicle purchase, registration, use and motor fuels, road and parking pricing Effectiveness may drop with higher incomes 
Influence mobility needs through land use regulations, and infrastructure planning Particularly appropriate for countries that are building up their transportation systems 
Investment in attractive public transport facilities and non-motorised forms of transport 

Buildings [6.8]

Appliance standards and labelling Periodic revision of standards needed 
Building codes and certification Attractive for new buildings. Enforcement can be difficult 
Demand-side management programmes Need for regulations so that utilities may profit 
Public sector leadership programmes, including procurement Government purchasing can expand demand for energy-efficient products 
Incentives for energy service companies (ESCOs) Success factor: Access to third party financing 

Industry [7.9]

Provision of benchmark information May be appropriate to stimulate technology uptake. Stability of national policy important in view of international competitiveness 
Performance standards 
Subsidies, tax credits 
Tradable permits Predictable allocation mechanisms and stable price signals important for investments 
Voluntary agreements Success factors include: clear targets, a baseline scenario, third party involvement in design and review and formal provisions of monitoring, close cooperation between government and industry 


[8.6, 8.7, 8.8]

Financial incentives and regulations for improved land management, maintaining soil carbon content, efficient use of fertilizers and irrigation  May encourage synergy with sustainable development and with reducing vulnerability to climate change, thereby overcoming barriers to implementation 

Forestry/forests [9.6]

Financial incentives (national and international) to increase forest area, to reduce deforestation, and to maintain and manage forests  Constraints include lack of investment capital and land tenure issues. Can help poverty alleviation 
Land use regulation and enforcement 

Waste management [10.5]

Financial incentives for improved waste and wastewater management May stimulate technology diffusion 
Renewable energy incentives or obligations Local availability of low-cost fuel 
Waste management regulations Most effectively applied at national level with enforcement strategies 


a) Public RD & D investment in low emissions technologies have proven to be effective in all sectors

23. Policies that provide a real or implicit price of carbon could create incentives for producers and consumers to significantly invest in low-GHG products, technologies and processes. Such policies could include economic instruments, government funding and regulation (high agreement, much evidence).

  • An effective carbon-price signal could realize significant mitigation potential in all sectors [11.3, 13.2].
  • Modelling studies, consistent with stabilization at around 550 ppm CO2-eq by 2100 (see Box SPM.3), show carbon prices rising to 20 to 80 US$/tCO2-eq by 2030 and 30 to 155 US$/tCO2-eq by 2050. For the same stabilization level, studies since TAR that take into account induced technological change lower these price ranges to 5 to 65 US$/tCO2-eq in 2030 and 15 to 130 US$/tCO2-eq in 2050 [3.3, 11.4, 11.5].
  • Most top-down, as well as some 2050 bottom-up assessments, suggest that real or implicit carbon prices of 20 to 50 US$/tCO2-eq, sustained or increased over decades, could lead to a power generation sector with low-GHG emissions by 2050 and make many mitigation options in the end-use sectors economically
  • attractive. [4.4,11.6]
  • Barriers to the implementation of mitigation options are manifold and vary by country and sector. They can be related to financial, technological, institutional, informational and behavioural aspects [4.5, 5.5, 6.7, 7.6, 8.6, 9.6, 10.5].

24. Government support through financial contributions, tax credits, standard setting and market creation is important for effective technology development, innovation and deployment. Transfer of technology to developing countries depends on enabling conditions and financing (high agreement, much evidence).

  • Public benefits of RD&D investments are bigger than the benefits captured by the private sector, justifying government support of RD&D.
  • Government funding in real absolute terms for most energy research programmes has been flat or declining for nearly two decades (even after the UNFCCC came into force) and is now about half of the 1980 level [2.7, 3.4, 4.5, 11.5, 13.2].
  • Governments have a crucial supportive role in providing appropriate enabling environment, such as, institutional, policy, legal and regulatory frameworks[31], to sustain investment flows and for effective technology transfer – without which it may be difficult to achieve emission reductions at a significant scale. Mobilizing financing of incremental costs of low-carbon technologies is important. International technology agreements could strengthen the knowledge infrastructure [13.3].
  • The potential beneficial effect of technology transfer to developing countries brought about by Annex I countries action may be substantial, but no reliable estimates are available [11.7].
  • Financial flows to developing countries through Clean Development Mechanism (CDM) projects have the potential to reach levels of the order of several billions US$ per year[32], which is higher than the flows through the Global Environment Facility (GEF), comparable to the energy oriented development assistance flows, but at least an order of magnitude lower than total foreign direct investment flows. The financial flows through CDM, GEF and development assistance for technology transfer have so far been limited and geographically unequally distributed [12.3, 13.3].

25. Notable achievements of the UNFCCC and its Kyoto Protocol are the establishment of a global response to the climate problem, stimulation of an array of national policies, the creation of an international carbon market and the establishment of new institutional mechanisms that may provide the foundation for future mitigation efforts (high agreement, much evidence).

  • The impact of the Protocol’s first commitment period relative to global emissions is projected to be limited. Its economic impacts on participating Annex-B countries are projected to be smaller than presented in TAR, that showed 0.2-2% lower GDP in 2012 without emissions trading, and 0.1-1.1% lower GDP with emissions trading among Annex-B countries [1.4, 11.4, 13.3].

26. The literature identifies many options for achieving reductions of global GHG emissions at the international level through cooperation. It also suggests that successful agreements are environmentally effective, cost-effective, incorporate distributional considerations and equity, and are institutionally feasible (high agreement, much evidence).

  • Greater cooperative efforts to reduce emissions will help to reduce global costs for achieving a given level of mitigation, or will improve environmental effectiveness [13.3].
  • Improving, and expanding the scope of, market mechanisms (such as emission trading, Joint Implementation and CDM) could reduce overall mitigation costs [13.3].
  • Efforts to address climate change can include diverse elements such as emissions targets; sectoral, local, sub-national and regional actions; RD&D programmes; adopting common policies; implementing development oriented actions; or expanding financing instruments. These elements can be implemented in an integrated fashion, but comparing the efforts made by different countries quantitatively would be complex and resource intensive [13.3].
  • Actions that could be taken by participating countries can be differentiated both in terms of when such action is undertaken, who participates and what the action will be. Actions can be binding or non-binding, include fixed or dynamic targets, and participation can be static or vary over time [13.3].
  1. ^  See the IPCC Special Report on Methodological and Technological Issues in Technology Transfer.
  2. ^  Depends strongly on the market price that has fluctuated between 4 and 26 US$/tCO2-eq and based on approximately 1000 CDM proposed plus registered projects likely to generate more than 1.3 billion emission reduction credits before 2012.