Editing IPCC:AR6/WGII/Cross-Chapter-Paper-6 (section)

=== CCP6.3.1 Key Risks ===

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Key risks arising from changing climate hazards are presented in Table CCP6.6 (details in SMCCP6.4). Changing levels and magnitude of climate hazards translate into different levels of risks for ecosystems, industry, society and infrastructure (Figure CCP6.4) (see [[#Meredith--2019|Meredith et al., 2019]] Figures 3.5, 3.10 (Arctic), Figure 3.6 (Antarctic). In the Arctic, these risks are often also shaped by non-climatic factors ( [[#Huntington--2019|Huntington et al., 2019]] ; [[#Ford--2021|Ford et al., 2021]] ), including ongoing colonial legacies, land dispossession, landscape fragmentation and resulting challenges in the valuing and meaningful use of IK and LK (Box CCP6.2) ( [[#Huntington--2019|Huntington et al., 2019]] ; [[#Kelman--2019|Kelman and Næss, 2019]] ; [[#Ford--2020|Ford et al., 2020]] ). Available literature enabled assessment of particular polar assets based on projected future risk and including consideration of non-climatic compounding factors under 1°C, 2°C, 3°C and 4°C global warming above pre-industrial level, including sea ice ecosystems, marine mammals, sea birds, fisheries, infrastructure (Arctic only), local mobility (Arctic only) and coastal erosion (Arctic only) (Figure CCP6.5) (details in SMCCP6.4).

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[[File:ec235c8a818afe7c384074d9a67a204a IPCC_AR6_WGII_Figure_CCP6_005.png]]

'''Figure CCP6.5 |''' '''Burning ember of the relative risks to select assets in the polar regions as a function of global mean surface temperature increase since pre-industrial times including: (1) sea ice ecosystems, (2) marine mammals, (3) sea birds, (4) fisheries, (5) infrastructure (Arctic only), (6) local mobility (Arctic only) and (7) coastal erosion (Arctic only).''' The supporting literature and methods are provided in SMCCP6.5

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[[File:f20dbcd2122c0753aaaa75eb4afe92bc IPCC_AR6_WGII_Figure_CCP6_004.png]]

'''Figure CCP6.4 |''' '''Rapid assessment for relative risk by sector (''' '''''y''''' '''-axis) and climate hazard (''' '''''x''''' '''-axis) for polar regions based on an assessment of asset-specific vulnerability and exposure across climate hazards (see SMCCP6''' '''.''' '''4 for methodological details).''' For each unique combination, the hazard by sector risk was ranked as very high (very high risk and ''high confidence'' ), high (significant impacts and risk, ''high to medium confidence'' ), medium (impacts are detectable and attributable to climate change, ''medium confidence'' ) or low/not detected/positive (risk is low or not detectable). Blank cells are those where the assessment was not applicable or not conducted. Risks identified through the rapid assessment were further evaluated in the chapter assessments (see corresponding sector text for full assessment of risk and impacts).

'''Table CCP6.5 |''' Key risks (KR) and illustrative examples in polar regions identified through the processes described in [[IPCC:Wg2:Chapter:Chapter-16|Chapter 16]] and SMCCP6.4.

{| class="wikitable"
|-
! Key risk

! Direct and indirect factors contributing to risk

|-
| KR1. Risk to marine ecosystems and species (CCP6.2.2; CCP6.2.3)

| * Warming, MHW, sea ice loss, glacial and IS melt, OA, invasive species, harmful algae blooms
* Narrow thermal niches, altered marine habitat, hampered calcification, higher corrosivity for CaCO 3 shell/skeleton, phenological mismatch, physiological/life history effects, sensitive food web relationships, reduced trophic (energy) transfer efficiencies, increased light availability, nutrient limitation, and changes to salinity, stratification, oxygen levels

|-
| KR2. Risk to terrestrial and freshwater ecosystems and species (CCP6.2.4)

| * Warming, hydrological changes, terrestrial heat waves, change in rain and snow events, increased wild- and mega-fire events in Arctic, permafrost thaw, and erosion
* Vegetation browning/greening, narrow thermal niches, physiological/ life history effects, sensitive food web relationships, parasites and disease

|-
| KR3. Risk to commercial and private infrastructure (CCP6.2.6)

| * Permafrost freeze–thaw, extreme heat and precipitation, rapid warm-thaw events, storms, increased wave activity, storm surges, flooding, landslides and erosion
* Roads, airstrips, railways, ports, commercial buildings, private homes, ice cellars, traditional snow/ice/water travel routes, other infrastructure
* Permafrost freeze–thaw and SLR impacting cultural assets, including cultural heritage sites

|-
| KR4. Risk to food and nutritional security (CCP6.2.5)

| * Warming, OA, sea ice loss, permafrost loss, changes to precipitation, wildfires, hydrological changes
* Access to marine areas increased, to coastal and terrestrial areas decreased; effects on subsistence and commercial species

|-
| KR5. Increased polar shipping traffic with cascading risks for navigation, safety, ecosystems and culture (CCP6.2.4; CCP6.2.5; Box CCP6.2; FAQ CCP6.1)

| * Substantial reduction in sea ice extent and thickness
* Marine subsistence species; coastal communities; Inuit hunters; ship operators; tourism operators; mining companies

|-
| KR6. Increased mental health challenges and impacts on Indigenous Peoples and culture (CCP6.2.6.4; CCP6.2.7; CCP6.2.8. Box CCP6.2; FAQ CCP6.3)

| * Warming temperature; heatwaves; ice changes; changes in snow cover; permafrost thaw; coastal erosion; changing landscapes

|-
| KR7. Risk from polar change for global processes and SLR (FAQ CCP6.1)

| * Reduction in Arctic sea ice, sheets and glaciers have implications for planetary albedo and ocean stratification and salinity, acceleration of global warming, potential effects on global overturning circulation and Northern Hemisphere weather patterns
* Cultural and resource connections to global sustainable development

|}

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