Editing IPCC:AR6/WGIII/Chapter-7 (section)

=== 7.5.1 Regional GHG Emissions and Land Dynamics ===

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In most of the assessed mitigation pathways, the AFOLU sector is of great importance for climate change mitigation as it (i) turns from a source into a sink of atmospheric CO 2 due to large-scale afforestation and reforestation, (ii) provides high amounts of biomass for bioenergy with or without CCS and (iii), even under improved agricultural management, still causes residual non-CO 2 emissions from agricultural production and (iv) interplays with sustainability dimensions other than climate action ( [[#Popp--2017|Popp et al. 2017]] ; [[#Rogelj--2017|Rogelj et al. 2017]] ; Van Vuuren et al. 2018; [[#Frank--2018|Frank et al. 2018]] ; [[#Hasegawa--2018|Hasegawa et al. 2018]] ; [[#van%20Soest--2019|van Soest et al. 2019]] ). Regional AFOLU GHG emissions in scenarios with &lt;4°C warming in 2100 (scenario category C7), as shown in Figure 7.13, are shaped by considerable CH 4 and N 2 O emissions throughout 2050 and 2100, mainly from ASIA and AFRICA. CH 4 emissions from enteric fermentation are largely caused by ASIA, followed by AFRICA, while CH 4 emissions from paddy rice production are almost exclusively caused by ASIA. N 2 O emissions from animal waste management and soils are more equally distributed across region.

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'''Figure 7.13 | Land-based regional GHG emissions and removals in 2050 (top) and 2100 (bottom) for scenarios from the AR6 Database with &lt;1.''' '''5°C (C1, C2), &lt;2°C (C3, C4), &lt;3°C (C5, C6) and &lt;4°C (C7) global warming in 2100 (scenario type is indicated by colour).''' The categories shown include CH 4 emissions from enteric fermentation (EntF) and rice production (Rice), N 2 O emissions from animal waste management (AWM) and fertilisation (Soil). The category CO 2 Land includes CO 2 emissions from land-use change as well as removals due to afforestation/reforestation. BECCS reflects the CO 2 emissions captured from bioenergy use and stored in geological deposits. The annual GHG emission data from various models and scenarios is converted to CO 2 equivalents using GWP factors of 27 for CH 4 and 273 for N 2 O. The data is summarised in boxplots (Tukey style), which show the median (vertical line), the interquartile range (IQR box) and the range of values within 1.5 × interquartile range at either end of the box (horizontal lines) across all models and scenarios. The number of data points available for each emission category, scenario type, region and year is shown at the edge of each panel. Regional definitions: AFRICA = sub-Saharan Africa, ASIA = Asia, LAM = Latin America and Caribbean, MID_EAST = Middle East, OECD90+EU = OECD 90 and EU, REF = Reforming Economies of Eastern Europe and the Former Soviet Union.

In most regions, CH 4 and N 2 O emission are both lower in mitigation pathways that limit warming to 3°C (&gt;50%) or lower (C1–C6) compared to scenarios with &lt;4°C ( [[#Popp--2017|Popp et al. 2017]] ; [[#Rogelj--2018a|Rogelj et al. 2018a]] ). In particular, the reduction of CH 4 emissions from enteric fermentation in ASIA and AFRICA is profound. Land-related CO 2 emissions, which include emissions from deforestation as well as removals from afforestation, are slightly negative (i.e., AFOLU systems turn into a sink) in &lt;1.5°C, &lt;2°C and &lt;3°C mitigation pathways compared to &lt;4°C scenarios. Carbon sequestration via BECCS is most prominent in ASIA, LAM, AFRICA and OECD90+EU, which are also the regions with the highest bioenergy area.

Figure 7.14 indicates that regional land-use dynamics in scenarios with &lt;4°C warming in 2100 are characterised by rather static agricultural land (i.e., cropland and pasture) in ASIA, LAM, OECD90+EU and REF, and increasing agricultural land in AFRICA. Bioenergy area is relatively small in all regions. Agricultural land in AFRICA expands at the cost of forests and other natural land.

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'''Figure 7.14 | Regional change of major land cover types by 2050 (top) and 2100 (bottom) relative to 2020 for scenarios from the AR6 Database with &lt;1.''' '''5°C (C1, C2), &lt;2°C (C3, C4), &lt;3°C (C5, C6) and &lt;4°C (C7) global warming in 2100 (scenario type is indicated by colour).''' The data is summarised in boxplots (Tukey style), which show the median (vertical line), the interquartile range (IQR box) and the range of values within 1.5 × IQR at either end of the box (horizontal lines) across all models and scenarios. The number of data points available for each land cover type, scenario type, region and year is shown at the right edge of each panel. Regional definitions: AFRICA = sub-Saharan Africa, ASIA = Asia, LAM = Latin America and Caribbean, MID_EAST = Middle East, OECD90+EU = OECD 90 and EU, REF = Reforming Economies of Eastern Europe and the Former Soviet Union.

The overall land dynamics in &lt;1.5°C, &lt;2°C and &lt;3°C mitigation pathways are shaped by land-demanding mitigation options such as bioenergy and afforestation, in addition to the demand for other agricultural and forest commodities. Bioenergy production and afforestation take place largely in the (partly) tropical regions ASIA, LAM and AFRICA, but also in OECD90+EU. Land for dedicated second generation bioenergy crops and afforestation displace agricultural land for food production (cropland and pasture) and other natural land. For instance, in the &lt;1.5°C mitigation pathway in ASIA, bioenergy and forest area together increased by about 2.1 million km 2 between 2020 and 2100, mostly at the cost of cropland and pasture (median values). Such large-scale transformations of land use have repercussions on biogeochemical cycles (e.g., fertiliser and water) but also on the economy (e.g., food prices) and potential socio-political conditions.

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