Editing IPCC:AR6/SYR/Longer-Report (section)

==== 3.3.3 Sectoral Contributions to Mitigation ====

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'''All global modelled pathways that limit warming to 2°C (&gt;67%)''' '''or lower by 2100 involve rapid and deep and in most cases immediate GHG emissions reductions in all sectors (see also 4. 1, 4.5).''' Reductions in GHG emissions in industry, transport, buildings, and urban areas can be achieved through a combination of energy efficiency and conservation and a transition to low-GHG technologies and energy carriers (see also 4.5, Figure 4.4). Socio-cultural options and behavioural change can reduce global GHG emissions of end-use sectors, with most of the potential in developed countries, if combined with improved infrastructure design and access. ( ''high confidence'' ). { ''WGIII SPM C.3, WGIII SPM C.5, WGIII SPM C.6, WGIII SPM C.7.3, WGIII SPM C.8, WGIII SPM C.10.2'' }

'''Global modelled mitigation pathways reaching net zero CO''' '''2''' '''and GHG emissions include transitioning from fossil fuels without carbon capture and storage (CCS) to very low- or zero-carbon energy sources, such as renewables or fossil fuels with CCS, demand-side measures and improving efficiency, reducing non-CO''' '''2''' '''GHG emissions, and CDR''' '''[[#footnote-021|136]]''' . In global modelled pathways that limit warming to 2°C or below, almost all electricity is supplied from zero or low-carbon sources in 2050, such as renewables or fossil fuels with CO 2 capture and storage, combined with increased electrification of energy demand. Such pathways meet energy service demand with relatively low energy use, through e.g., enhanced energy efficiency and behavioural changes and increased electrification of energy end use. Modelled global pathways limiting global warming to 1.5°C (&gt;50%) with no or limited overshoot generally implement such changes faster than pathways limiting global warming to 2°C (&gt;67%). ( ''high confidence'' ) { ''WGIII SPM C.3, WGIII SPM C.3.2, WGIII SPM C.4, WGIII TS.4.2; SR1.5 SPM C.2.2'' }

'''AFOLU mitigation options, when sustainably implemented, can deliver large-scale GHG emission reductions and enhanced CO''' '''2''' '''removal; however, barriers to implementation and trade-offs may result from the impacts of climate change, competing demands on land, conflicts with food security and livelihoods, the complexity of land ownership and management systems, and cultural aspects (see 3.4.1).''' All assessed modelled pathways that limit warming to 2°C (&gt;67%) or lower by 2100 include land-based mitigation and land-use change, with most including different combinations of reforestation, afforestation, reduced deforestation, and bioenergy. However, accumulated carbon in vegetation and soils is at risk from future loss (or sink reversal) triggered by climate change and disturbances such as flood, drought, fire, or pest outbreaks, or future poor management.. ( ''high confidence'' ). { ''WGI SPM B.4.3; WGII SPM B.2.3, WGII SPM B.5.4; WGIII SPM C.9, WGIII SPM C.11.3, WGIII SPM D.2.3, WGIII TS.4.2, 3.4; SR1.5 SPM C.2.5; SRCCL SPM B.1.4, SRCCL SPM B.3, SRCCL SPM B.7'' }

'''In addition to deep, rapid, and sustained emission reductions, CDR can fulfil three complementary roles: lowering net CO''' '''2''' '''or net GHG emissions in the near term; counterbalancing ‘ hard-to-abate’ residual emissions (e.g., some emissions from agriculture , aviation, shipping, industrial processes) to help reach net zero CO''' '''2''' '''or GHG emissions, and achieving net negative CO''' '''2''' '''or GHG emissions if deployed at levels exceeding annual residual emissions (''' '''''high confidence)''''' '''.''' CDR methods vary in terms of their maturity, removal process, time scale of carbon storage, storage medium, mitigation potential, cost, co-benefits, impacts and risks, and governance requirements. ( ''high confidence'' ). Specifically, maturity ranges from lower maturity (e.g., ocean alkalinisation) to higher maturity (e.g., reforestation); removal and storage potential ranges from lower potential (&lt;1 Gt CO 2 yr ''-1'' , e.g., blue carbon management) to higher potential (&gt;3 Gt CO 2 yr ''-1'' , e.g., agroforestry); costs range from lower cost (e.g., –45 to 100 USD tCO 2 ''-1'' for soil carbon sequestration) to higher cost (e.g., 100 to 300 USD tCO 2 ''-1'' for direct air carbon dioxide capture and storage) ( ''medium confidence'' ). Estimated storage timescales vary from decades to centuries for methods that store carbon in vegetation and through soil carbon management, to ten thousand years or more for methods that store carbon in geological formations. ( ''high confidence'' ). Afforestation, reforestation, improved forest management, agroforestry and soil carbon sequestration are currently the only widely practiced CDR methods ( ''high confidence'' ). Methods and levels of CDR deployment in global modelled mitigation pathways vary depending on assumptions about costs, availability and constraints ( ''high confidence'' ). { ''WGIII SPM C.3.5, WGIII SPM C.11.1, WGIII SPM C.11.4'' }

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