Editing IPCC:AR6/WGII/Chapter-10 (section)

== Executive Summary ==

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'''Observed surface air temperature has been increasing since the 20th century all over Asia (''' '''''high confidence''''' [[#footnote-012|1]] ''').''' Significant warming has intensified the threat to social and economic sustainability ( ''medium confidence'' ). Rising temperatures increase the likelihood of the threat of heatwaves across Asia, droughts in arid and semiarid areas of West, Central and South Asia, delays and weakening of the monsoon circulation in South Asia, floods in monsoon regions in South, Southeast and East Asia, and glacier melting in the Hindu Kush Himalaya region ( ''medium confidence'' ). {10.3.1, 10.3.3}

'''Asian countries are experiencing a hotter summer climate, resulting in an increase in energy demand for cooling at a rapid rate, together with the population growth (''' '''''high confidence''''' '''). Decrease in precipitation influences energy demand as well as desalination, underground water pumping and other energy-intensive methods are increasingly used for water supply (''' '''''high confidence''''' ''').''' More energy demands in summer seasons will exceed any energy savings from relatively lower heating demand due to warmer winter. Among 13 developing countries with large energy consumption in Asia, 11 are exposed to high-energy insecurity and industrial-systems risk ( ''high confidence'' ). {10.4.1}

'''Asian terrestrial-ecosystems change is driven by global warming, precipitation and Asian monsoon alteration, permafrost thawing and extreme events like dust storms, along with natural and human-related factors which are in interplay''' '''(''' '''''high confidence''''' ''').''' Treeline position in North Asian mountains moves upwards after the 1990s, while in Himalaya treeline demonstrates a multi-directional shift, either moves upwards or does not show upslope advance, or moves downwards. This can be explained by site-specific complex interaction of positive effect of warming on tree growth, drought stress, change in snow precipitation, land-use change (especially grazing) and other factors ( ''high confidence'' ). The increased considerable changes in biomes in Asia are a response to warming ( ''medium confidence'' ). Terrestrial and freshwater species, populations and communities are altered in line with climate change across Asia ( ''medium to high confidence'' ). Climate change, human activity and lightning have caused the increase in wildfire severity and area burned in North Asia after the 1990s ( ''medium confidence'' ). Length of plant growth season has increased in some parts of East and North Asia, while the opposite trend, or no change at all, has been observed in other parts ( ''high confidence'' ). Observed biodiversity or habitat losses of animals plants have been linked to climate change in some parts of Asia ( ''high confidence'' ). There is evidence that climate change can alter species interaction or spatial distribution of invasive species in Asia ( ''high confidence'' ). Changes in ecosystems in Asia during the 21st century are expected to be driven by projected climatic, natural and socioeconomic changes. Across Asia, under a range of representative concentration pathways and other scenarios, rising temperatures are expected to contribute to a northward shift of biome boundaries and an upwards shift of mountain treeline ( ''medium confidence'' ). {10.4.2}

'''Coastal habitats of Asia are diverse, and the impacts of climate change including rising temperatures, ocean acidification and sea level rise (SLR) has brought negative effects to the services and the livelihoods of people depending on it (''' '''''high confidence''''' ''').''' The degree of bleaching of coral reefs is diverse among different presences of stress-tolerant symbionts and higher thermal thresholds. The risk of irreversible loss of coral reefs, tidal marshes, seagrass meadows, plankton community and other marine and coastal ecosystems increases with global warming, especially at 2°C temperature rise or more ( ''high confidence'' ). Mangroves in the region continue to face threats due to pollution, conversion for aquaculture, agriculture and climate-based threats like SLR and coastal erosion. {10.4.3}

'''Both climatic and non-climatic drivers such as socio-economic changes have created water stress conditions in both water supply and demand in all sub-regions of Asia, except for North Asia (''' '''''medium confidence''''' ''').''' These changes in space and time directly or indirectly have affected water-use sectors and services. By mid-21st Century, the international transboundary river basins of Amu Darya, Indus, Ganges could face severe water scarcity challenges due to climatic variability and changes acting as stress multipliers ( ''high confidence'' ) ''.'' Due to global warming, Asian countries could experience an increase in drought conditions (5–20%) by the end of this century ( ''high confidence'' ). {10.4.4}

'''The Asian glaciers were in minor-area shrinkage and mass loss during 2006–2016, resulting in the instability of water resource supply (''' '''''high confidence''''' ''').''' Glaciers in Asia are the water resources of about 220 million people in the downstream areas. The glacier melt water in the southern Tibetan Plateau increased during 1998–2007, and will further increase till 2050. The total amount and area of glacier lakes have increased during the past decade ( ''high confidence'' ). More glacier collapses and surges were found in western Tibetan Plateau.Glacier lake outburst flood (GLOF) will threaten the securities of the local and downstream communities ( ''high confidence'' ). Snowmelt water contributed 19% of the increase change in runoff of arid regions’ rivers in Xinjiang, China, and 10.6% of the upper Brahmaputra River during 2003–2014 ( ''medium confidence'' ). {10.4.4, Box 10.4}

'''Since IPCC AR5, more studies have reinforced the earlier findings on the spatio-temporal diversity of climate-change impacts on food production in Asia depending on the geographic location, agroecology and crops grown, recognising that there are winners and losers associated with the changing climate across scales''' '''(''' '''''high confidence''''' ''').''' Most of these impacts have been associated with drought, monsoon rain and oceanic oscillations, the frequency and severity of which have been linked with the changing climate. Climate-related risks to agriculture and food systems in Asia will progressively escalate with the changing climate, with differentiated impacts across the region ( ''medium confidence'' ). Major projected impacts of climate change in the agriculture and food sectors include decline in fisheries, aquaculture, crop production (particularly in South and Southeast Asia), reduction in livestock production in Mongolia and changes in crop, farming systems and crop areas in almost all regions, with negative implications to food security ( ''medium confidence'' ). In India, rice production can decrease from 10 to 30%, whereas maize production can decrease from 25 to 70% assuming a range of temperature increase from 1°C to 4°C. Similarly, rice production in Cambodia can decrease by 45% by 2080 under the high-emissions scenario. Occurrence of pests, such as the golden apple snail ( ''Pomacea canaliculate'' ), associated with the predicted increase in climatically suitable habitats in 2080, threatens the top Asian rice-producing countries including China, India, Indonesia, Bangladesh, Vietnam, Thailand, Myanmar, the Philippines and Japan. Increasing temperatures, changing precipitation levels and extreme climate events, such as heatwaves, droughts and typhoons, will persist in being important vulnerability drivers that will shape agricultural productivity particularly in South, Southeast and Central Asia. {10.4.5, Figure 10.6}

'''Asian urban areas are considered high-risk locations from projected climate change, extreme events, unplanned urbanisation and rapid land-use change (''' '''''high confidence''''' ''') but also sites of ongoing adaptation (''' '''''medium confidence''''' ''').''' Asia is home to the largest share of people living in informal settlements, with 332 million in Eastern and Southeast Asia, and 197 million in Central and Southern Asia. By 2050, 64% of Asia’s population will be urban. Coastal cities, especially in South and Southeast Asia, are expected to see significant increases in average annual economic losses between 2005 and 2050 due to flooding, with very high losses in East Asian cities under the high-emissions scenario ( ''high confidence'' ). Climate change will amplify the urban heat-island effect across Asian cities (especially South and East Asia) at 1.5°C and 2°C temperature rise, both substantially larger than under the present climate ( ''medium evidence, high agreement'' ). Under the high-emissions scenario, higher risks from extreme temperature and precipitation are projected for almost all cities ( ''medium confidence'' ), with impacts on freshwater availability, regional food security, human health and industrial outputs. By 2080, 940 million to 1.1 billion urban dwellers in South and Southeast Asia could be affected by extreme heat lasting more than 30 d yr –1 ( ''high confidence'' ), with poorer populations affected the most. {10.4.6, Cross-Chapter Box URBAN in Chapter 6}

'''Climate change has caused direct losses due to the damage in infrastructure, disruption in services and affected supply chains in Asia''' '''(''' '''''medium confidence''''' ''') and will increase risk to infrastructure as well as provide opportunities to invest in climate-resilient infrastructure and green jobs (''' '''''medium confidence''''' ''').''' At higher warming, key infrastructures, such as power lines, transport by roads and railways, and built infrastructures, such as airports and harbours, are more exposed to climate-induced extreme events, especially in coastal cities ( ''medium confidence'' ). Evidence on urban adaptation across Asia is growing with examples of infrastructural adaptation (e.g., flood protection measures, and climate-resilient highways and power infrastructure), institutional adaptation (e.g., sustainable land-use planning, zoning plans), nature ecosystem-based solutions (e.g., mangrove restoration, restoring and managing urban green spaces, urban farming), technological solutions (e.g., smart cities, early warning systems) and behavioural adaptation (e.g., improved awareness and preparedness measures). However, adaptation actions tend to be in the initial stages and more reactive (57% of urban adaptations focus on preparatory interventions, such as capacity building, and 43% of cities report implemented adaptation interventions) ( ''medium confidence'' ). The degree of implementation of urban adaptation is uneven with large cities receiving more funding and priority, and smaller cities and towns, and peri-urban spaces, seeing relatively lower adaptation action ( ''medium confidence'' ). {10.4.6}

'''Climate change is increasing vector-borne and water-borne diseases, undernutrition, mental disorders and allergy-related illnesses in Asia by increasing hazards such as heatwaves, flooding and drought, and air pollutants, in combination with more exposure and vulnerability (''' '''''high confidence''''' ''').''' Sub-regional diversity in socioeconomic and demographic contexts (e.g., ageing, urban compared with agrarian society, increasing population compared with reduced birth rate, high income compared with low to middle income) and geographic characteristics largely define the differential vulnerabilities and impacts within countries in Asia. Under the medium-to-high emissions scenario, rising temperatures and extreme climate events will have an increasing impact on human health and well-being with varying types and magnitudes of impact across Asia ( ''high confidence'' ) ''.'' More frequent hot days and intense heatwaves will increase heat-related deaths. Increased floods and droughts will have adverse impacts on food availability and the prices of food, resulting in increased undernourishment in South and Southeast Asia. Increases in heavy rain and temperature will increase the risk of diarrhoeal diseases, dengue fever and malaria in tropical and subtropical Asia. {10.4.7}

'''Increased climate variability and extreme events are already driving migration (''' '''''robust evidence, medium agreement''''' ''') and projecting that longer-term climate change will increase migration flows across Asia (''' '''''medium confidence''''' ''').''' One in three migrants comes from Asia, and the highest ratio of outward migrants is seen from hazard-exposed Pacific countries. In 2019, Bangladesh, China, India and the Philippines each recorded more than 4 million disaster displacements. In Southeast Asia and East Asia, cyclones, floods and typhoons triggered internal displacement of 9.6 million people, almost 30% of total global displacements in 2019. {Box 10.2}

'''There is a small but growing literature highlighting the importance of behavioural aspects of adaptation in Asia (''' '''''high confidence''''' '''), but this is restricted primarily to agriculture and disaster risk reduction (DRR).''' Factors motivating adaptation actions include risk perception, perceived self-efficacy, sociocultural norms and beliefs, previous experiences of impacts, levels of education and awareness ( ''high confidence'' ). There is growing evidence on behavioural aspects of individual adaptation but lesser evidence on the socio-cognitive factors motivating governments and private-sector actors to adapt. {10.5.3}

'''Climate change is already causing economic loss and damage across Asian regions, and this will increase under higher warming''' '''(''' '''''medium confidence''''' ''').''' Non-material losses and damages are reported to a lesser degree, but this is due to under-reporting and methodological issues with detection and attribution to climate change ( ''high confidence'' ). Loss and damage represents a key knowledge gap, especially in West, Central and North Asia. Insufficient literature differentiating loss and damage under future adaptation scenarios renders a comprehensive assessment of residual damages, along with future loss and damage, difficult. {Box 10.6}

'''Options such as climate-smart agriculture, ecosystem-based DRR and investing in urban blue–green infrastructure meet adaptation, mitigation and Sustainable Development Goals simultaneously, presenting opportunities for climate resilient development (CRD) pathways in Asia (''' '''''high confidence''''' ''').''' Climate risks, vulnerability and adaptation measures need to be factored into decision making across all levels of governance (high confidence). To help achieve this, there is a need to advance the current understanding of climate impacts across sectors and spatio-temporal scales, and improve on the current strategies in planning and budget allocation. More accurate forecasting of extreme events, risk awareness and prioritising individual and collective decision making also need to be addressed (high confidence). Options for Asian countries are transforming the risks of climate change into opportunities for the advancement of projects in the energy sector, including promoting investment in non-fossil energies, securing local natural gas resources, enhancing water harvesting, adopting green building technologies and encouraging multi-stakeholder partnerships. However, there are significant barriers to CRD such as fragmented, reactive governance; inadequate evidence on which actions to prioritise and how to sequence them; and finance deficits. Some Asian countries and regions offer solutions to overcome these barriers: through use of advanced technologies (in situ observation and remote sensing, a variety of new sensor technologies, citizen science, artificial intelligence and machine learning tools); regional partnerships and learning; improved forecasting capabilities; and better risk awareness (high confidence). {10.5, 10.6}

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