Editing IPCC:AR6/WGII/Chapter-11 (section)

====== Observed changes and impacts ======

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'''Ongoing climate trends have exacerbated many extreme events (''' '''''very high confidence''''' ''')''' . The Australian trends include further warming and sea level rise sea level rise (SLR), with more hot days and heatwaves, less snow, more rainfall in the north, less April–October rainfall in the southwest and southeast and more extreme fire weather days in the south and east. The New Zealand trends include further warming and sea level rise (SLR), more hot days and heatwaves, less snow, more rainfall in the south, less rainfall in the north and more extreme fire weather in the east. There have been fewer tropical cyclones and cold days in the region. Extreme events include Australia’s hottest and driest year in 2019 with a record-breaking number of days over 39°C, New Zealand’s hottest year in 2016, three widespread marine heatwaves during 2016–2020, Category 4 Cyclone Debbie in 2017, seven major hailstorms over eastern Australia and two over New Zealand from 2014–2020, three major floods in eastern Australia and three over New Zealand during 2019–2021 and major fires in southern and eastern Australia during 2019–2020. {11.2.1, Table 11.2, 11.3.8}

'''Climate trends and extreme events have combined with exposure and vulnerabilities to cause major impacts for many natural systems, with some experiencing or at risk of irreversible change in Australia (''' '''''very''''' '''''high confidence''''' ''')''' '''and in New Zealand (''' '''''high confidence''''' ''')''' '''''.''''' For example, warmer conditions with more heatwaves, droughts and catastrophic wildfires have negatively impacted terrestrial and freshwater ecosystems. The Bramble Cay melomys, an endemic mammal species, became extinct due to loss of habitat associated with sea level rise (SLR) and storm surges in the Torres Strait. Marine species abundance and distributions have shifted polewards, and extensive coral bleaching events and loss of temperate kelp forests have occurred due to ocean warming and marine heatwaves across the region. In New Zealand’s southern Alps, from 1978 to 2016, the area of 14 glaciers declined 21%, and extreme glacier mass loss was at least 6 times more likely in 2011 and 10 times more likely in 2018 due to climate change. The end-of-summer snowline elevation for 50 glaciers rose 300 m from 1949 to 2019. {11.3.1.1, 11.3.2.1, Table 11.2b, Table 11.4, Table 11.6, Table 11.9}

'''Climate trends and extreme events have combined with exposure and vulnerabilities to cause major impacts for some human systems (''' '''''high confidence''''' ''').''' Socioeconomic costs arising from climate variability and change have increased. Extreme heat has led to excess deaths and increased rates of many illnesses. Nuisance and extreme coastal flooding have increased due to sea level rise (SLR) superimposed upon high tides and storm surges in low-lying coastal and estuarine locations, including impacts on cultural sites, traditions and lifestyles of Aboriginal and Torres Strait Islander Peoples in Australia and Tangata Whenua Māori in New Zealand. Droughts have caused financial and emotional stress in farm households and rural communities. Tourism has been negatively affected by coral bleaching, fires, poor ski seasons and receding glaciers. Governments, business and communities have experienced major costs associated with extreme weather, droughts and sea level rise (SLR). {11.3, 11.4, 11.5.2, Table 11.2, Boxes 11.1–11.6}

'''Climate impacts are cascading and compounding across sectors and socioeconomic and natural systems (''' '''''high confidence''''' ''').''' Complex connections are generating new types of risks, exacerbating existing stressors and constraining adaptation options. An example is the impacts that cascade between interdependent systems and infrastructure in cities and settlements. Another example is the 2019–2020 southeast Australia wildfires, which burned 5.8 to 8.1 million hectares, with 114 listed threatened species losing at least half of their habitat and 49 losing over 80%, over 3,000 houses destroyed, 33 people killed, a further 429 deaths and 3230 hospitalisations due to cardiovascular or respiratory conditions, AUD$1.95 billion in health costs, AUD$2.3 billion in insured losses and AUD$3.6 billion in losses for tourism, hospitality, agriculture and forestry. {11.5.1, Box 11.1}

'''Increasing climate risks are projected to exacerbate existing vulnerabilities and social inequalities and inequitie''' '''''s''''' '''(''' '''''high confidence''''' ''').''' These include inequalities between Indigenous and non-Indigenous Peoples and between generations, rural and urban areas, incomes and health status, increasing the climate risks and adaptation challenges faced by some groups and places. Resultant climate change impacts include the displacement of some people and businesses and threaten social cohesion and community well-being. {11.3.5, 11.3.6, 11.3.10, 11.4}

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