Editing IPCC:AR6/WGII/TS (section)

=== Food systems and food security ===

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'''TS.C.3 Climate change will increasingly add pressure on food production systems, undermining food security (''' '''''high confidence''''' '''). With every increment of warming, exposure to climate hazards will grow substantially (''' '''''high confidence''''' '''), and adverse impacts on all food sectors will become prevalent, further stressing food security (''' '''''high confidence''''' '''). Regional disparity in risks to food security will grow with warming levels, increasing poverty traps, particularly in regions characterised by a high level of human vulnerability (''' '''''high confidence''''' ''').''' (Figure TS.4) { 4.5.1, 4.6.1, 5.2.2, 5.4.3, 5.4.4, 5.5.3, 5.8.3, 5.9.3, 5.12.4, 7.3.1, 9.8.2, 9.8.5, 13.5.1, 14.5.4, 16.5.2, 16.6.3, CCB MOVING PLATE }

'''TS.C.3.1 Climate change will increasingly add pressure on terrestrial food production systems with every increment of warming (''' '''''high confidence''''' ''').''' Some current global crop and livestock areas will become climatically unsuitable depending on the emissions scenario ( ''high confidence'' ; 10% globally by 2050, by 2100 over 30% under SSP-8.5 versus below 8% under SSP1-2.6). Compared to 1.5°C global warming level, 2°C global warming level will even further negatively impact food production where current temperatures are already high as in lower latitudes ( ''high confidence'' ). Increased and potentially concurrent climate extremes will increase simultaneous losses in major food-producing regions ( ''medium confidence'' ). The adverse effects of climate change on food production will become more severe when global temperatures rise by more than 2°C ( ''high confidence'' ). At 3°C or higher global warming levels, exposure to climate hazards will grow substantially ( ''high confidence'' ), further stressing food production, notably in sub-Saharan Africa and South and South East Asia ( ''high confidence'' ). (Figure TS.4) { 4.5.1, 4.6.1, 5.2.2, 5.4.3, 5.4.4, 5.5.3, 5.8.3, 5.9.3, 5.12.4, 9.8.2, 9.8.5, 11.3.4, 13.5.1, 14.5.4, 16.5.2, 16.6.3, CCB MOVING PLATE }

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[[File:0d7a088013fc7886dbb2d00b4ef261de IPCC_AR6_WGII_Figure_TS_004a.png]] [[File:aa2978174dc25988f1f40b39fc2ed841 IPCC_AR6_WGII_Figure_TS_004b.png]]

'''Figure TS.4 |''' '''Synthetic diagrams of global and sectoral assessments and examples of regional key risks.''' Diagrams show the change in the levels of impacts and risks assessed for global warming of 0–5°C global surface temperature change relative to pre-industrial period (1850–1900) over the range.

'''(a)''' Global surface temperature changes in °C relative to 1850–1900. These changes were obtained by combining CMIP6 model simulations with observational constraints based on past simulated warming, as well as an updated assessment of equilibrium climate sensitivity (Box TS.2). Changes relative to 1850–1900 based on 20-year averaging periods are calculated by adding 0.85°C (the observed global surface temperature increase from 1850–1900 to 1995–2014) to simulated changes relative to 1995–2014. ''Very likely'' ranges are shown for SSP1-2.6 and SSP3-7.0 (WGI AR6 Figure SPM.8). Assessments were carried out at the global scale for (b), (c), (d) and (e).

'''(b)''' The Reasons for Concern (RFC) framework communicates scientific understanding about accrual of risk for five broad categories. Diagrams are shown for each RFC, assuming low to no adaptation (i.e., adaptation is fragmented, localized and comprises incremental adjustments to existing practices). However, the transition to a very high risk level has an emphasis on irreversibility and adaptation limits. Undetectable risk level (white) indicates no associated impacts are detectable and attributable to climate change; moderate risk (yellow) indicates associated impacts are both detectable and attributable to climate change with at least ''medium confidence'' , also accounting for the other specific criteria for key risks; high risk (red) indicates severe and widespread impacts that are judged to be high on one or more criteria for assessing key risks; and very high risk level (purple) indicates very high risk of severe impacts and the presence of significant irreversibility or the persistence of climate-related hazards, combined with limited ability to adapt due to the nature of the hazard or impacts/risks. The horizontal line denotes the present global warming of 1.09°C which is used to separate the observed, past impacts below the line from the future projected risks above it. RFC1: Unique and threatened systems: ecological and human systems that have restricted geographic ranges constrained by climate-related conditions and have high endemism or other distinctive properties. Examples include coral reefs, the Arctic and its Indigenous Peoples, mountain glaciers and biodiversity hotspots. RFC2: Extreme weather events: risks/impacts to human health, livelihoods, assets and ecosystems from extreme weather events such as heatwaves, heavy rain, drought and associated wildfires, and coastal flooding. RFC3: Distribution of impacts: risks/impacts that disproportionately affect particular groups due to uneven distribution of physical climate change hazards, exposure or vulnerability. RFC4: Global aggregate impacts: impacts to socio-ecological systems that can be aggregated globally into a single metric, such as monetary damages, lives affected, species lost or ecosystem degradation at a global scale. RFC5: Large-scale singular events: relatively large, abrupt and sometimes irreversible changes in systems caused by global warming, such as ice sheet disintegration or thermohaline circulation slowing. Assessment methods are described in SM16.6 and are identical to AR5, but are enhanced by a structured approach to improve robustness and facilitate comparison between AR5 and AR6. Risks for (c) terrestrial and freshwater ecosystems and (d) ocean ecosystems.

For '''(c)''' and '''(d)''' , diagrams shown for each risk assume low to no adaptation. The transition to a very high risk level has an emphasis on irreversibility and adaptation limits.

'''(e)''' Climate-sensitive human health outcomes under three scenarios of adaptation effectiveness. The assessed projections were based on a range of scenarios, including SRES, CMIP5, and ISIMIP, and, in some cases, demographic trends. The diagrams are truncated at the nearest whole °C within the range of temperature change in 2100 under three SSP scenarios in panel (a).

'''(f)''' Examples of regional key risks. Risks identified are of at least ''medium confidence'' level. Key risks are identified based on the magnitude of adverse consequences (pervasiveness of the consequences, degree of change, irreversibility of consequences, potential for impact thresholds or tipping points, potential for cascading effects beyond system boundaries); likelihood of adverse consequences; temporal characteristics of the risk; and ability to respond to the risk, e.g., by adaptation. The full set of 127 assessed global and regional key risks is given in SMTS.4 and SM16.7. Diagrams are provided for some risks. The development of synthetic diagrams for Small Islands, Asia and Central and South America were limited by the availability of adequately downscaled climate projections, with uncertainty in the direction of change, the diversity of climatologies and socio-economic contexts across countries within a region, and the resulting low number of impact and risk projections for different warming levels. Absence of risks diagrams does not imply absence of risks within a region. (Box TS.2) { Figure 2.11, Figure SM3.1, Figure 7.9, Figure 9.6, Figure 11.6, Figure 13.28, 16.5, 16.6, Figure 16.15, SM16.3, SM16.4, SM16.5, SM16.6 (methodologies), SM16.7, Figure CCP4.8, Figure [https://www.ipcc.ch/chapter/ts#CCP4.1 CCP4.1] 0, Figure [https://www.ipcc.ch/chapter/ts#CCP6.5 CCP6.5] , WGI AR6 2, WGI AR6 SPM A.1.2, WGI AR6 Figure SPM.8 }

'''TS.C.3.2 Climate change will significantly alter aquatic food provisioning services, with direct impacts on food-insecure people (''' '''''high confidence''''' ''').''' Global ocean animal biomass will decrease by 5.7% ± 4.1% and 15.5% ± 8.5% under SSP1-2.6 and SSP5-8.5 respectively by 2080–2099 relative to 1995–2014 ( ''medium confidence'' ), affecting food provisioning, revenue value and distribution. Catch composition will change regionally, and the vulnerability of fishers will partially depend on their ability to move, diversify and leverage technology ( ''medium confidence'' ). Global marine aquaculture will decline under increasing temperature and acidification conditions by 2100, with potential short-term gains for finfish aquaculture in some temperate regions and overall negative impacts on bivalve aquaculture due to habitat reduction ( ''medium confidence'' ). Changes in precipitation, sea level rise, temperature and extreme events will negatively affect food provisioning from inland aquatic systems ( ''medium confidence'' ), which provide a significant source of livelihoods and food for direct human consumption, particularly in Asia and Africa. { 3.4.2, 3.4.3, 3.5.3, 3.6.2, 3.6.3, 5.8.3, 5.9.3, 5.13, 9.8.5, 13.5.1, 14.5.2, [https://www.ipcc.ch/chapter/ts#CCP6.2.3 CCP6.2.3] , [https://www.ipcc.ch/chapter/ts#CCP6.2.4 CCP6.2.4] , [https://www.ipcc.ch/chapter/ts#CCP6.2.5 CCP6.2.5] , [https://www.ipcc.ch/chapter/ts#CCP6.2.6 CCP6.2.6] , [https://www.ipcc.ch/chapter/ts#CCP6.2 CCP6.2.8] , CCB MOVING PLATE, CCB SLR }

'''TS.C.3.3 Climate change will increasingly add significant pressure and regionally different impacts on all components of food systems, undermining all dimensions of food security (''' '''''high confidence''''' ''').''' Extreme weather events will increase risks of food insecurity via spikes in food prices, reduced food diversity and reduced income for agricultural and fishery livelihoods ( ''high confidence'' ), preventing achievement of the UN SDG 2 (‘Zero Hunger’) by 2030 in regions with limited adaptive capacities, including Africa, small island states and South Asia ( ''high confidence'' ). With about 2°C warming, climate-related changes in food availability and diet quality are estimated to increase nutrition-related diseases and the number of undernourished people by 2050, affecting tens (under low vulnerability and low warming) to hundreds of millions of people (under high vulnerability and high warming, i.e., SSP-3-RCP6.0), particularly among low-income households in low- and middle-income countries in sub-Saharan Africa, South Asia and Central America ( ''high confidence'' ), for example, between 8 million under SSP1-6.0 to up to 80 million people under SSP3-6.0. At 3°C or higher global warming levels, adverse impacts on all food sectors will become prevalent, further stressing food availability ( ''high confidence'' ), agricultural labour productivity and food access ( ''medium confidence'' ). Regional disparity in risks to food security will grow at these higher warming levels, increasing poverty traps, particularly in regions characterised by a high level of human vulnerability ( ''high confidence'' ). { 4.5.1, 4.6.1, 5.2.2, 5.4.3, 5.4.4, 5.5.3, 5.8.3, 5.9.3, 5.12.4, 7.3.1, 9.8.2, 9.8.5, 13.5.1, 14.5.4, 16.5.2, 16.6.3, CCB MOVING PLATE }

'''TS.C.3.4 Climate change is projected to increase malnutrition through reduced nutritional quality, access to balanced food and inequality (''' '''''high confidence''''' ''').''' Increased CO 2 concentrations promote crop growth and yield but reduce the density of important nutrients in some crops ( ''high confidence'' ) with projected increases in undernutrition and micronutrient deficiency, particularly in countries that currently have high levels of nutrient deficiency ( ''high confidence'' ) and regions with low access to diverse foods ( ''medium confidence'' ). Marine-dependent communities, including Indigenous Peoples and local peoples, will be at increased risk of malnutrition due to losses of seafood-sourced nutrients ( ''medium confidence'' ). { 3.5.3, 5.2.2, 5.4.2, 5.4.3, 5.5.2, 5.12.1, 5.12.4, 7.3.1, 9.8.5, 16.5.2, [https://www.ipcc.ch/chapter/ts#CCP6.2.3 CCP6.2.3] , [https://www.ipcc.ch/chapter/ts#CCP6.2.4 CCP6.2.4] , [https://www.ipcc.ch/chapter/ts#CCP6.2.5 CCP6.2.5] , [https://www.ipcc.ch/chapter/ts#CCP6.2.6 CCP6.2.6] , [https://www.ipcc.ch/chapter/ts#CCP6.2 CCP6.2.8] , CCB MOVING PLATE }

'''TS.C.3.5 Climate change will further increase pressures on those terrestrial ecosystem services which support global food production systems (''' '''''high confidence''''' ''').''' Climate change will reduce the effectiveness of pollination as species are lost from certain areas, or the coordination of pollinator activity and flower receptiveness will be disrupted in some regions ( ''high confidence'' ). Greenhouse gas emissions will negatively impact air, soil and water quality, exacerbating direct climatic impacts on yields ( ''high confidence'' ). { 5.4.3, 5.5.3, 5.7.1, 5.7.4, 5.9.4, 5.10.3, Box 5.3, Box 5.4, 13.10.2, 14.5.4, CCB MOVING PLATE, SRCCL }

'''TS.C.3.6 Climate change will compromise food safety through multiple pathways (''' '''''high confidence''''' ''').''' Higher temperatures and humidity will expand the risk of aflatoxin contamination into higher-latitude regions ( ''high confidence'' ). More frequent and intense flood events and increased melting of snow and ice will increase food contamination ( ''high confidence'' ). Aquatic food safety will decrease through increased detrimental impacts from harmful algal blooms ( ''high confidence'' ) and human exposure to elevated bioaccumulation of persistent organic pollutants and methylmercury ( ''low to medium confidence'' ). These negative food safety impacts will be greater without adaptation and fall disproportionately on low-income countries and communities with high consumption of seafood, including coastal Indigenous communities ( ''medium confidence'' ). { 3.6.3, 5.4.3, 5.8.1, 5.8.3, 5.11.1, 5.12.4, Box 5.10, 7.3.1, 14.5.6, CCB ILLNESS }

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