Many adaptation and mitigation options can help address climate change, but no single option is sufficient by itself.
Effective implementation depends on policies and cooperation at all scales, and can be enhanced through integrated responses that link mitigation and adaptation with other societal objectives.
(p 46)
The costs of achieving nearly universal access to electricity and clean fuels for cooking and heating [across the developing world] are projected to be between USD 72 to 95 billion per year until 2030 with minimal effects on GHG emissions (limited evidence, medium agreement) and multiple benefits in health and air pollutant reduction (high confidence).
(p 56)
Adaptation options for coral reef systems are generally limited to reducing other stressors, mainly by enhancing water quality and limiting pressures from tourism and fishing, but their efficacy will be severely reduced as thermal stress and ocean acidification increase.
(AR5 Synthesis Report — Longer Report, 2014, p 48)
Contents
Common enabling factors and constraints for adaptation and mitigation responses
Response options for adaptation
Response options for mitigation
Policy approaches for adaptation and mitigation, technology and finance
Trade-offs, synergies, and integrated responses
Intergovernmental Panel on Climate Change
- AR5 Synthesis Report — Longer Report, 1 November 2014.
Adaptation and Mitigation
Common enabling factors and constraints for adaptation and mitigation responses
Adaptation and mitigation responses are underpinned by common enabling factors.
These include- effective institutions and governance,
- innovation and investments in environmentally sound technologies and infrastructure,
- sustainable livelihoods, and
- behavioural and lifestyle choices.
Innovation and investments in environmentally sound infrastructure and technologies can reduce greenhouse gas emissions and enhance resilience to climate change (very high confidence). …
Adaptation and mitigation are constrained by the inertia of global and regional trends in- economic development,
- greenhouse gas emissions,
- resource consumption,
- infrastructure and settlement patterns,
- institutional behaviour, and
- technology
Some constraints may be overcome through- new technologies,
- financial resources,
- increased institutional effectiveness and governance, or
- changes in social and cultural attitudes and behaviours.
Vulnerability to climate change, greenhouse gas emissions, and the capacity for adaptation and mitigation are strongly influenced by livelihoods, lifestyles, behaviour and culture (medium agreement, medium evidence). …
For many regions and sectors, enhanced capacities to mitigate and adapt are part of the foundation essential for managing climate change risks (high confidence).
(p 46)
Improving institutions as well as enhancing coordination and cooperation in governance can help overcome regional constraints associated with mitigation, adaptation, and disaster risk reduction (very high confidence).
Response Options for Adaptation
Adaptation options exist in all sectors, but their context for implementation and potential to reduce climate-related risks differs across sectors and regions.
Some adaptation responses involve significant co-benefits, synergies and trade-offs.
Increasing climate change will increase challenges for many adaptation options. …
People, governments and the private sector are starting to adapt to a changing climate.
Since the AR4, understanding of response options has increased, with improved knowledge of their benefits, costs, and links to sustainable development.
Adaptation can take a variety of [forms] depending on its context …
- Social, ecological asset and infrastructure development
- Technological process optimization
- Integrated natural resources management
- Institutional, educational and behavioural change or reinforcement
- Financial services, including risk transfer
- Information systems to support early warning and proactive planning
Opportunities to enable adaptation planning and implementation exist in all sectors and regions, with diverse potential and approaches depending on context.
The need for adaptation along with associated challenges are expected to increase with climate change (very high confidence).
Freshwater resources
(p 48)
Adaptive water management techniques, including- scenario planning,
- learning based approaches, and
- flexible and low-regret solutions,
(p 47)
Terrestrial and freshwater ecosystems
Management actions can reduce but not eliminate risks of impacts to terrestrial and freshwater ecosystems due to climate change (high confidence).
Coastal systems and low-lying areas
[C]oastal adaptation options include those based on- integrated coastal zone management,
- local community participation,
- ecosystems-based approaches and
- disaster risk reduction
Marine systems and oceans
Marine forecasting and early warning systems as well as reducing non-climatic stressors have the potential to reduce risks for some fisheries and aquaculture industries, but options for unique ecosystems such as coral reefs are limited (high confidence).
Food production system / Rural areas
Adaptation options for agriculture include- technological responses,
- enhancing smallholder access to credit and other critical production resources,
- strengthening institutions at local to regional levels, and
- improving market access through trade reform
Urban areas, key economic sectors and services
Urban adaptation benefits from- effective multi-level governance,
- alignment of policies and incentives,
- strengthened local government and community adaptation capacity,
- synergies with the private sector, and
- appropriate financing and institutional development
Human health, security and livelihoods
Adaptation options that focus on strengthening existing delivery systems and institutions, as well as insurance and social protection strategies, can improve health, security and livelihoods in the near term (high confidence).
Significant co-benefits, synergies, and trade-offs exist between adaptation and mitigation and among different adaptation responses; interactions occur both within and across regions and sectors (very high confidence).
Response options for mitigation
Mitigation options are available in every major sector.
Mitigation can be more cost-effective if [it] combines measures to- reduce energy use and the greenhouse gas intensity of end-use sectors,
- decarbonize energy supply,
- reduce net emissions and
- enhance carbon sinks in land-based sectors.
A broad range of sectoral mitigation options is available that can- reduce GHG emission intensity,
- improve energy intensity through enhancements of technology, behaviour, production and resource efficiency, and
- enable structural changes or changes in activity. …
Well-designed systemic and cross-sectoral mitigation strategies are more cost-effective in cutting emissions than a focus on individual technologies and sectors; with efforts in one sector affecting the need for mitigation in others (medium confidence).
(p 49)
Decarbonizing (ie reducing the carbon intensity) electricity generation is a key component of cost-effective mitigation strategies in achieving low stabilization levels (of about 450 to about 500 ppm CO2eq, at least as likely as not to limit warming to 2°C above pre-industrial levels) (medium evidence, high agreement). …
[Such emissions trajectories] are characterized by [emission] reductions of 90% or more below 2010 levels between 2040 and 2070. …
Efficiency enhancements and behavioural changes, in order to reduce energy demand compared to baseline scenarios without compromising development, are a key mitigation strategy in scenarios reaching atmospheric CO2eq concentrations of about 450 to about 500 ppm by 2100 (robust evidence, high agreement). …
(p 50)
Decarbonization of the energy supply sector (ie reducing the carbon intensity) requires upscaling of low- and zero-carbon electricity generation technologies (high confidence).
[To realize a low-concentration stabilization scenario] the share of low-carbon electricity supply (comprising renewable energy (RE), nuclear and CCS, including BECCS) [needs to increase] from the current share of approximately 30% to more than 80% by 2050 and 90% by 2100, and fossil fuel power generation without CCS is phased out almost entirely by 2100.
[A] growing number of RE technologies have achieved a level of maturity to enable deployment at significant scale since AR4 (robust evidence, high agreement) and nuclear energy is a mature low-GHG emission source of baseload power, [however] its share of global electricity generation has been declining (since 1993).
GHG emissions from energy supply can be reduced significantly by replacing current world average coal-fired power plants with modern, highly efficient natural gas combined-cycle power plants or combined heat and power plants, provided that … fugitive emissions associated with extraction and supply are low or mitigated.
Behaviour, lifestyle and culture have a considerable influence on energy use and associated emissions, with high mitigation potential in some sectors, in particular when complementing technological and structural change (medium evidence, medium agreement). …
The most cost-effective mitigation options in forestry are afforestation, sustainable forest management and reducing deforestation, with large differences in their relative importance across regions.
In agriculture, the most cost-effective mitigation options are cropland management, grazing land management, and restoration of organic soils (medium evidence, high agreement). …
Bioenergy can play a critical role for mitigation, but there are issues to consider, such as the sustainability of practices and the efficiency of bioenergy systems (robust evidence, medium confidence).
(p 51)
Mitigation measures intersect with other societal goals creating the possibility of co-benefits or adverse side-effects.
These intersections, if well-managed, can strengthen the basis for undertaking climate mitigation actions (robust evidence, medium agreement).
Policy approaches for adaptation and mitigation, technology and finance
Effective adaptation and mitigation responses will depend on policies and measures across multiple scales:
- international,
- regional,
- national and
- sub-national.
International and Regional Cooperation on Adaptation and Mitigation
The United Nations Framework Convention on Climate Change (UNFCCC) is the main multilateral forum focused on addressing climate change, with nearly universal participation. …
Existing and proposed international climate change cooperation arrangements vary in their focus and degree of centralization and coordination.
(p 52)
While a number of new institutions are focused on adaptation funding and coordination, adaptation has historically received less attention than mitigation in international climate policy (robust evidence, medium agreement). …
The Kyoto Protocol offers lessons towards achieving the ultimate objective of the UNFCCC, particularly with respect to participation, implementation, flexibility mechanisms, and environmental effectiveness (medium evidence, low agreement). …
Several conceptual models for effort-sharing have been identified in research.
(p 53)
Policy linkages among regional, national, and sub-national climate policies offer potential climate change mitigation benefits (medium evidence, medium agreement). …
Regional initiatives between national and global scales are being developed and implemented, but their impact on global mitigation has been limited to date (medium confidence). …
International cooperation for supporting adaptation planning and implementation has assisted in the creation of adaptation strategies, plans, and actions at national, sub-national, and local levels (high confidence).
National and Sub-National Policies
Adaptation
Adaptation experience is accumulating across regions in the public and private sector and within communities (high confidence). …
National governments play key roles in adaptation planning and implementation (high agreement, robust evidence). …
While local government and the private sector have different functions, which vary regionally, they are increasingly recognized as critical to progress in adaptation, given their roles in scaling up adaptation of communities, households, and civil society and in managing risk information and financing (medium evidence, high agreement). …
Institutional dimensions of adaptation governance, including the integration of adaptation into planning and decision making, play a key role in promoting the transition from planning to implementation of adaptation (high agreement, robust evidence).
(p 54)
Existing and emerging economic instruments can foster adaptation by providing incentives for anticipating and reducing impacts (medium confidence).
Mitigation
There has been a considerable increase in national and sub-national mitigation plans and strategies since AR4. …
However, there has not yet been a substantial deviation in global emissions from the past trend. …
Since AR4, there has been an increased focus on policies designed to integrate multiple objectives, increase co-benefits and reduce adverse side-effects (high confidence). …
Sector-specific policies have been more widely used than economy-wide policies (medium evidence, high agreement). …
In principle, mechanisms that set a carbon price, including cap and trade systems and carbon taxes, can achieve mitigation in a cost-effective way, but have been implemented with diverse effects due in part to national circumstances as well as policy design. …
Economic instruments in the form of subsidies may be applied across sectors, and include a variety of policy designs, such as tax rebates or exemptions, grants, loans and credit lines.
(p 55)
The reduction of subsidies for GHG-related activities in various sectors can achieve emission reductions, depending on the social and economic context (high confidence). …
[The] complete removal of subsidies to fossil fuels in all countries could result in reductions in global aggregate emissions by mid- century (medium evidence, medium agreement). …
Regulatory approaches and information measures are widely used and are often environmentally effective (medium evidence, medium agreement). …
Mitigation policy could devalue fossil fuel assets and reduce revenues for fossil fuel exporters, but differences between regions and fuels exist (high confidence). …
Interactions between or among mitigation policies may be synergistic or may have no additive effect on reducing emissions (medium evidence, high agreement). …
Sub-national climate policies are increasingly prevalent, both in countries with national policies and in those without. …
Co-benefits and adverse side-effects of mitigation could affect achievement of other objectives such as those related to- human health,
- food security,
- biodiversity,
- local environmental quality,
- energy access,
- livelihoods, and
- equitable sustainable development. …
Technology development and transfer
Technology policy (development, diffusion and transfer) complements other mitigation policies across all scales from international to sub-national, but worldwide investment in research in support of GHG mitigation is small relative to overall public research spending (high confidence). …
Many adaptation efforts also critically rely on diffusion and transfer of technologies and management practices, but their effective use depends on a suitable institutional, regulatory, social and cultural context (high confidence).
Investment and finance
Substantial reductions in emissions would require large changes in investment patterns (high confidence). …
There is no widely agreed definition of what constitutes climate finance, but estimates of the financial flows associated with climate change mitigation and adaptation are available.
(p 57)
In many countries, the private sector plays central roles in the processes that lead to emissions as well as to mitigation and adaptation.
Within appropriate enabling environments, the private sector, along with the public sector, can play an important role in financing mitigation and adaptation (medium evidence, high agreement). …
Financial resources for adaptation have become available more slowly than for mitigation in both developed and developing countries.
Limited evidence indicates that there is a gap between global adaptation needs and the funds available for adaptation (medium confidence).
Trade-offs, synergies, and integrated responses
There are many opportunities to link mitigation, adaptation and the pursuit of other societal objectives through integrated responses (high confidence).
Successful implementation relies on relevant tools, suitable governance structures, and enhanced capacity to respond (medium confidence). …
Increasing efforts to mitigate and adapt to climate change imply an increasing complexity of interactions, encompassing connections among human health, water, energy, land use, and biodiversity (very high confidence).
(p 58)
Integration of adaptation and mitigation into planning and decision-making can create synergies with sustainable development (high confidence). …
Effective integrated responses depend on suitable tools and governance structures, as well as adequate capacity (medium confidence). …
An integrated approach to energy planning and implementation that explicitly assesses the potential for co-benefits and the presence of adverse side-effects can capture complementarities across multiple climate, social and environmental objectives (medium confidence). …
Explicit consideration of interactions among water, food, energy, and biological carbon sequestration plays an important role in supporting effective decisions for climate resilient pathways (medium evidence, high agreement). …
An integrated response to urbanization provides substantial opportunities for enhanced resilience, reduced emissions, and more sustainable development (medium confidence).
(p 59)
