rlacombe/ClimateX huggingface dataset:
These types of adaptations are more effective when built on trusted relationships and effective coordination among involved parties, and are inclusive of the diversity of actors in a coastal community.Box FAQ 3.4 (continued) Table 3.27 | Conclusions from previous IPCC assessments about implemented adaptation, enablers and limits, and contribution to Sustainable Development Goals (SDGs) AR5 SR15 SROCC Degree of implementation (Section 3.6.3.1)‘The analysis and implementation of coastal adaptation towards climate-resilient and sustainable coasts has progressed more significantly in developed countries than in developing countries (high confidence)’ (Wong et al., 2014).‘Adaptation (to SLR) is already happening (high confidence) and will remain important over multi-centennial time scales’ (Hoegh-Guldberg et al., 2018a).‘A diversity of adaptation responses to coastal impacts and risks have been implemented around the world, but mostly as a reaction to current coastal risk or experienced disasters (IPCC AR6_WGII, confidence: high)
Conservation and restoration (Section 3.6.3.2)‘With continuing climate change, local adaptation measures (such as conservation) or a reduction in human activities (such as fishing) may not sufficiently offset global-scale effects on marine ecosystems (high confidence)’ (Pörtner et al., 2014).‘Existing and restored natural coastal ecosystems may be effective in reducing the adverse impacts of rising sea levels and intensifying storms by protecting coastal and deltaic regions (medium confidence)’ (Hoegh-Guldberg et al., 2018a).‘Ecosystem restoration may be able to locally reduce climate risks (medium confidence) but at relatively high cost and effectiveness limited to low-emissions scenarios and to less-sensitive ecosystems (IPCC AR6_WGII, confidence: high)
Enablers, barriers and limits of adaptation (Section 3.6.3.3)‘Adaptation strategies for ocean regions beyond coastal waters are generally poorly developed but will benefit from international legislation and expert networks, as well as marine spatial planning (high agreement)’ (Hoegh-Guldberg et al., 2014).‘Lower rates of change [associated with a 1.5°C temperature increase] enhance the ability of natural and human systems to adapt, with substantial benefits for a wide range of terrestrial, freshwater, wetland, coastal and ocean ecosystems (including coral reefs) (high confidence)’ (Hoegh-Guldberg et al., 2018a).‘There are a broad range of identified barriers and limits for adaptation to climate change in ecosystems and human systems (IPCC AR6_WGII, confidence: high)
Limitations include [...] availability of technology, knowledge and financial support, and existing governance structures (IPCC AR6_WGII, confidence: medium)
Existing ocean-governance structures are already facing multi-dimensional, scale-related challenges because of climate change [...] (IPCC AR6_WGII, confidence: high)
NbS that contribute to climate adaptation, also known as ecosystem-based adaptations (EBA), are cross-cutting actions that harness ecosystem functions to restore, protect and sustainably manage marine ecosystems facing climate-change impacts, while also benefiting social systems and human security (Abelson et al., 2015; Barkdull and Harris, 2019) and supporting biodiversity (IPCC AR6_WGII, confidence: high)
NbS are expected to contribute to global adaptation and mitigation goals (IPCC AR6_WGII, confidence: high)
Marine NbS are cost-effective, can generate social, economic and cultural co-benefits, and can contribute to the conservation of biodiversity in the near- to mid- term (IPCC AR6_WGII, confidence: high)
The feasibility and effectiveness of these adaptations are assessed in Figure 3.24.3.6.3.1 Degree of Implementation and Evidence of Effectiveness Across Sectors 3.6.3.1.1 Coastal community development and settlement Coastal adaptation often addresses the risk of flooding and erosion from SLR, changes in storm activity and degradation of coastal ecosystems and their services (IPCC AR6_WGII, confidence: high)
Hard-engineered structures like seawalls are generally more costly than nature-based adaptations (IPCC AR6_WGII, confidence: high)
Field and modelling studies confirm that wetland restoration and preservation are key actions to restore coastal protection and reduce community vulnerability to flooding (IPCC AR6_WGII, confidence: very high)
Restoring coral reefs, oyster reefs and mangroves (Section 3.6.2.1) and protecting macrophyte meadows dissipates wave energy (Section 3.4.2.1; Yates et al., 2017; Beck et al., 2018; Wiberg et al., 2019; Menéndez et al., 2020), accretes sediment and elevate shorelines, which reduces exposure to waves and storm surges, and offsets erosional losses (IPCC AR6_WGII, confidence: medium)
However, irreversible regime shifts in ocean ecosystems due to SLR and extreme events, such as MHWs, can limit or compromise restoration in the long term (IPCC AR6_WGII, confidence: high)
Therefore, restoration and conservation are more successful when non-climate drivers are also minimised (IPCC AR6_WGII, confidence: high)
Managed realignment is the best option to reduce risks from SLR (IPCC AR6_WGII, confidence: high)
Implementation of protective measures varies among nations and lack of financial resources limits the options available (IPCC AR6_WGII, confidence: very high)
Improving capacity to predict anomalous conditions in coastal and marine ecosystems (Jacox et al., 2019; Holbrook et al., 2020; Jacox et al., 2020), storm-driven flooding in reef-lined coasts (Scott et al., 2020; Winter et al., 2020) and fisheries stocks (Payne et al., 2017; Tommasi et al., 2017; Muhling et al., 2018) can improve forecasts of coastal and marine resources; these can enhance sustainability of wild-capture fisheries under climate change (IPCC AR6_WGII, confidence: high)
Current impacts of sea level rise The rate of global mean SLR was 1.35 mm yr–1 (0.78–1.92 mm yr–1, very likely range) during 1901–1990, faster than during any century in at least 3000 years (IPCC AR6_WGII, confidence: high)
Global mean SLR has accelerated to 3.25 mm yr–1 (2.88–3.61 mm yr–1, very likely range) during 1993–2018 (IPCC AR6_WGII, confidence: high)
The largest observed changes in coastal ecosystems are being caused by the concurrence of human activities, waves, current-induced sediment transport and extreme storm events (IPCC AR6_WGII, confidence: medium)
Projected risks to coastal communities, infrastructure and ecosystems Risks from SLR are very likely to increase by one order of magnitude well before 2100 without adaptation and mitigation action as agreed by parties to the Paris Agreement (IPCC AR6_WGII, confidence: very high)
Global mean SLR is likely to continue accelerating under SSP1-2.6 and more strongly forced scenarios (Figure BoxSLR1; WGI AR6 Chapter 9; Oppenheimer et al., 2019; Fox-Kemper et al., 2021), increasing the risk of chronic coastal flooding at high tide, serious flooding during extreme events such as swells, storms and hurricanes, and erosion, and coastal ecosystem losses across many low-lying and erodible coasts (IPCC AR6_WGII, confidence: very high)
Coastal ecosystems can migrate landward or grow vertically in response to SLR, but their resilience and capacity to keep up with SLR will be compromised by ocean warming and other drivers, depending on regions and species, for example, above 1.5°C for coral reefs (IPCC AR6_WGII, confidence: high)
Sediments and space for landward retreat are crucial for mangroves, salt marshes and beach ecosystems (IPCC AR6_WGII, confidence: high)
This is a reason for concern given that rapid SLR after the last glacial–interglacial transition caused a drowning of coral reefs (high confidence) (Camoin and Webster, 2015; Sanborn et al., 2017; Webster et al., 2018), extensive loss of coastal land and islands, habitats and associated biodiversity (high confidence) (AR6 WGI Chapter 9; Fruergaard et al., 2015; Fernández-Palacios et al., 2016; Hamilton et al., 2019; Helfensdorfer et al., 2019; Kane and Fletcher, 2020; Fox-Kemper et al., 2021), and triggered Neolithic migrations in Europe and Australia (IPCC AR6_WGII, confidence: medium)
Even if climate warming is stabilised at 2°C to 2.5°C GWL, coastlines will continue to reshape over millennia, affecting at least 25 megacities and drowning low-lying areas where 0.6–1.3 billion people lived in 2010 (IPCC AR6_WGII, confidence: medium)
Solutions, opportunities and limits to adaptation The ability to adapt to current coastal impacts, to cope with future coastal risks and to prevent further acceleration of SLR beyond 2050 depends on immediate mitigation and adaptation actions (IPCC AR6_WGII, confidence: very high)
Risks can be anticipated, planned and decided upon, and adaptation interventions can be implemented over the coming decades considering their often long lead- and lifetimes, irrespective of the large uncertainty about SLR beyond 2050 (IPCC AR6_WGII, confidence: high)
Adaptation capacity and governance to manage risks from projected SLR typically require decades to implement and institutionalise (IPCC AR6_WGII, confidence: high)
Sea level rise is likely to compound social conflict in some settings (IPCC AR6_WGII, confidence: high)
Only avoidance and relocation can remove coastal risks for the coming decades, while other measures only delay impacts for a time, have increasing residual risk or perpetuate risk and create ongoing legacy effects and virtually certain property and ecosystem losses (IPCC AR6_WGII, confidence: high)
Effective responses to rising sea level involve locally applicable combinations of decision analysis, land-use planning, public participation and conflict resolution approaches; together these can anticipate change and help to chart adaptation pathways, over time addressing the governance challenges due to rising sea level (IPCC AR6_WGII, confidence: high)
Ecosystem-based adaptation can reduce impacts on human settlements and bring substantial co-benefits, such as ecosystem services restoration and carbon storage, but they require space for sediment and ecosystems and have site-specific physical limits, at least above 1.5°C GWL (IPCC AR6_WGII, confidence: high)
Transboundary agreements on shifting fisheries will reduce the risk of overharvesting (IPCC AR6_WGII, confidence: medium)
Despite the potential for adaptive management to achieve sustainable fisheries, outcomes will very likely be inequitable (Gaines et al., 2018; Lam et al., 2020), with lower- income countries suffering the greater biomass and economic losses, increasing inequalities, especially under higher-emission scenarios (IPCC AR6_WGII, confidence: high)
Engineered solutions, such as seawalls and revetments, have traditionally been used to address coastal erosion (Section 3.6.3.1.1), but soft infrastructure approaches, including beach nourishment, submerged breakwaters and groins, and NbS (Section 3.6.2.1), are becoming more common, partly due to demand from the tourism industry (IPCC AR6_WGII, confidence: medium)
Increased Arctic traffic due to ice loss can benefit trade, transportation and tourism (medium confidence), but will also affect Arctic marine ecosystems and livelihoods (IPCC AR6_WGII, confidence: high)
Forecasts facilitate preventive public health measures (World Health Organisation and United Nations Children’s Fund, 2017), or seafood harvest guidance (Maguire et al., 2016; Leadbetter et al., 2018; Anderson et al., 2019; Bolin et al., 2021), reducing risks of disease outbreaks, waste and contaminated seafood entering the market (IPCC AR6_WGII, confidence: medium)
Current MPAs offer conservation benefits such as increases in biomass and diversity of habitats, populations and communities (IPCC AR6_WGII, confidence: high)
But current MPAs do not provide resilience against observed warming and heatwaves in tropical-to-temperate ecosystems (IPCC AR6_WGII, confidence: medium)
Current placement and extent of MPAs will not provide substantial protections against projected climate change past 2050 (IPCC AR6_WGII, confidence: high)
In summary, MPAs and other marine spatial-planning tools have great potential to address climate-change mitigation and adaptation in ocean and coastal ecosystems, if they are designed and implemented in a coordinated way that takes into account ecosystem vulnerability and responses to projected climate conditions, considers existing and future ecosystem uses and non-climate drivers, and supports effective governance (IPCC AR6_WGII, confidence: high)
Employing the natural adaptive capacity of species or individuals in active restoration for corals and kelps with current technology involves fewer risks than assisted evolution or long- distance relocation (IPCC AR6_WGII, confidence: high)
Models show that a combination of available management approaches (restoration, reducing non-climate drivers) and speculative interventions (e.g., enhanced corals, reef shading) can contribute to sustaining some coral reefs beyond 1.5°C of global warming with declining effectiveness beyond 2°C of global warming (IPCC AR6_WGII, confidence: medium)
The icons at the bottom show the Sustainable Development Goals to which NbS in the ocean possibly contribute.Box FAQ 3.5 (continued) Adaptations implemented at the local level that consider IKLK systems are beneficial (IPCC AR6_WGII, confidence: high)
Recent evidence suggests that policies supporting local institutions can improve adaptation outcomes (IPCC AR6_WGII, confidence: medium)
Economic and financing barriers to marine adaptation are often higher in low- to middle- income countries, where resources influence governance and constrain options for implementation and maintenance (IPCC AR6_WGII, confidence: high)
Current financial flows are insufficient to meet the costs of coastal and marine impacts of climate change (very high confidence) and ocean- focused finance is unevenly distributed, with higher flows within, and to, developed countries (IPCC AR6_WGII, confidence: very high)
Maladaptation (WGII Chapter 16; Magnan et al., 2016) is a common risk of current project-based funding due to the pressure to produce concrete results (IPCC AR6_WGII, confidence: medium)
Maladaptation can be avoided through a focus on building adaptive capacity, community-based management, drivers of vulnerability and site-specific measures (IPCC AR6_WGII, confidence: low)
More research is needed to identify ways that governance and financing agreements can help overcome financial barriers and sociocultural constraints to avoid maladaptation in coastal ecosystems (IPCC AR6_WGII, confidence: high)
Communities and governments at all levels increasingly use decision- making frameworks (e.g., structured decision making) or decision- analysis tools to evaluate trade-offs between different responses, rather than applying generic best practices to different physical, technical or cultural contexts (IPCC AR6_WGII, confidence: high)
Focusing on user engagement, relationship building and the decision-making context ensures that climate services are useful to, and used by, different stakeholders (IPCC AR6_WGII, confidence: high)
Responding to climate-change impacts requires transformative governance (IPCC AR6_WGII, confidence: high)
Socio-institutional marine adaptations (Section 3.6.2.2) that support current livelihoods and help develop alternatives can contribute to attainment of social SDGs by enhancing social equity and supporting societal transformation (IPCC AR6_WGII, confidence: medium)
Marine adaptation also shows promise for helping support achievement of economic SDGs (IPCC AR6_WGII, confidence: medium)
Developing marine adaptation pathways that offer multiple benefits requires transformational adaptation (IPCC AR6_WGII, confidence: high)
Presently implemented adaptation activity, at the aggregate level, adversely affects multiple gender targets under SDG5 (IPCC AR6_WGII, confidence: high)
Not surprisingly, a large share of adaptation interventions (~60%) are forged in response to water-related hazards (IPCC AR6_WGII, confidence: high)
Approximately 163 million people live in unfamiliarly dry areas now (IPCC AR6_WGII, confidence: medium)
Substantially more people (~709 million) live in regions where annual maximum one-day precipitation has increased than regions where it has decreased (~86 million) (IPCC AR6_WGII, confidence: medium)
At the same time, more people (~700 million) are also experiencing longer dry spells than shorter dry spells since the 1950s (IPCC AR6_WGII, confidence: medium)
At the same time, groundwater in aquifers across the tropics has experienced enhanced episodic recharge from intense precipitation and flooding events (IPCC AR6_WGII, confidence: medium)
For a given evidence and agreement statement, different confidence levels can be assigned, but increasing levels of evidence and degrees of agreement are correlated with increasing confidence.Extreme weather events causing highly impactful floods and droughts have become more likely and (or) more severe due to anthropogenic climate change (IPCC AR6_WGII, confidence: high)
A significant share of those impacts are negative and felt disproportionately by already vulnerable communities (IPCC AR6_WGII, confidence: high)
In addition, precipitation and extreme weather events are linked to increased incidence and outbreaks of water-related diseases (IPCC AR6_WGII, confidence: high)
Between 3 and 4 billion people are projected to be exposed to physical water scarcity at 2°C and 4°C global warming levels (GWL), respectively (IPCC AR6_WGII, confidence: low)
Modified streamflow is also projected to affect inflows to urban storage reservoirs and increase the vulnerability of urban water services to hydro-meteorological extremes, particularly in less developed countries (IPCC AR6_WGII, confidence: high)
With RCP6.0 and SSP2, the global population exposed to extreme-to-exceptional total water storage drought is projected to increase from 3% to 8% over the 21st century (IPCC AR6_WGII, confidence: medium)
Direct flood damages are projected to increase by four to five times at 4°C compared to 1.5°C (IPCC AR6_WGII, confidence: medium)
Projected losses include a 1.2- to 1.8-fold increase in GDP loss due to flooding between 1.5°C and 2°C warming (IPCC AR6_WGII, confidence: medium)
Due to the combined effects of water and temperature changes, risks to agricultural yields could be three times higher at 3°C compared to 2°C (IPCC AR6_WGII, confidence: medium)
The number of internally displaced people in sub- Saharan Africa, South Asia and Latin America increased almost five times for RCP8.5 compared to RCP2.6 (IPCC AR6_WGII, confidence: low)
In contrast, responses are more policy-oriented and urban-focused in developed countries (IPCC AR6_WGII, confidence: high)
In addition, large- scale irrigation also affects local to regional climates, both in terms of temperature and precipitation change (IPCC AR6_WGII, confidence: high)
Roughly one third and one fourth of case studies on water adaptation also documents maladaptation and co-benefits, respectively (IPCC AR6_WGII, confidence: high)
A significant knowledge gap remains in knowing if observed adaptation benefits also translate to climate risk reduction, if so, by how much and under what conditions (IPCC AR6_WGII, confidence: medium)
However, residual impacts remain for some options and regions at all levels of warming, and the overall effectiveness decreases at higher warming levels (IPCC AR6_WGII, confidence: high)
SDGs cannot be met without adequate and safe water (high confidence), and water is fundamental to all systems transition (IPCC AR6_WGII, confidence: high)
However, barriers remain for low-income countries to access funds (medium confidence), and there is insufficient evidence on benefits for marginalised groups (IPCC AR6_WGII, confidence: medium)
The water intensity of mitigation must be managed in socially and politically acceptable ways to increase synergies with SDGs, improve water security and reduce trade-offs with adaptation (IPCC AR6_WGII, confidence: medium)
Water adaptation policies enabled through ethical co-production between holders of Indigenous knowledge, local knowledge and technical knowledge (medium confidence), through cooperation and coordinated actions among multiple actors, including women and all marginalised groups, at various levels of governance (IPCC AR6_WGII, confidence: medium)
First, approximately half the world’s population (~4 billion out of ~8 billion people) are assessed as being currently subject to severe water scarcity for at least some part fo the year (IPCC AR6_WGII, confidence: medium)
Currently, many people are experiencing climate change on a day-to-day basis through water-related impacts such as the increased frequency and intensity of heavy precipitation (high confidence) (Section 4.2.1.1, Seneviratne et al., 2021); accelerated melting of glaciers (high confidence) (Section 4.2.2, Douville et al., 2021); changes in frequency, magnitude and timing of floods (high confidence) (Section 4.2.4, Seneviratne et al., 2021); more frequent and severe droughts in some places (high confidence) (Section 4.2.5, Seneviratne et al., 2021); decline in groundwater storage and reduction in recharge (medium confidence) (Section 4.2.6, Douville et al., 2021) and water quality deterioration due to extreme events (IPCC AR6_WGII, confidence: medium)
Vulnerability to water-related impacts of climate change and extreme weather are already felt in all major sectors and are projected to intensify in the future, for example, in agriculture (high confidence) (Sections 4.3.1, 4.5.1); energy and industry (high confidence for observed drought impacts and projected impacts) (Sections 4.3.2, 4.5.2); water for health and sanitation (high confidence about links to precipitation extremes and disease outbreaks) (Sections 4.3.3, 4.5.3); water for urban, peri-urban and municipal sectors (IPCC AR6_WGII, confidence: medium)
Third, a large majority (~60%) of all adaptation responses documented since 2014 are about adapting to water-related hazards like droughts, floods and rainfall variability (Berrang-Ford et al., 2021b) (IPCC AR6_WGII, confidence: high)
Only ~20% of all documented case studies on observed water-related adaptations measure outcomes (positive or negative), but the link between positive outcomes and climate risk reduction is unclear and remains challenging to assess (Section 4.7.1) (IPCC AR6_WGII, confidence: medium)
On the other hand, most of the future projected water-related adaptations are more effective at lower GWLs (1.5°C) than at higher GWLs, showing the importance of mitigation for future adaptations to remain effective (IPCC AR6_WGII, confidence: high)
Therefore, minimising the risks to water security from climate change will require a full-systems view that considers the direct impacts of mitigation measures on water resources and their indirect effect via limiting climate change (IPCC AR6_WGII, confidence: high)
AR5 projected an increase in meteorological, agricultural and hydrological droughts in dry regions (IPCC AR6_WGII, confidence: medium)
The Special Report on Global Warming of 1.5°C (SR1.5) assessed that limiting global warming to 1.5°C is expected to substantially reduce the probability of extreme droughts, precipitation deficits and risks associated with water availability in some regions (IPCC AR6_WGII, confidence: medium)
On the other hand, higher risks to natural and human systems in a 2.0°C world would mean increased vulnerability for the poor, showing that socioeconomic drivers are expected to have a more significant influence on water-related risks and vulnerabilities than changes in climate alone (IPCC AR6_WGII, confidence: medium)
Climate change patterns of streamflow change include declines in western North America, northeast South America, the Mediterranean and South Asia (IPCC AR6_WGII, confidence: medium)
The Special Report on Climate Change and Land (SRCCL) stated that groundwater over-extraction for irrigation is causing depletion of groundwater storage (IPCC AR6_WGII, confidence: high)
The report also noted that precipitation changes, coupled with human drivers, will have a role in causing desertification, and water-driven soil erosion is projected to increase due to climate change (IPCC AR6_WGII, confidence: medium)