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

==== 11.3.6.1 Observed Impacts ====

<div id="h3-17-siblings" class="h3-siblings"></div>

There is ample evidence of health loss due to extreme weather in Australia and New Zealand, and rising temperatures, changing rainfall patterns and increasing fire weather have been attributed to anthropogenic climate change (11.2.1). Extreme heat leads to excess deaths and increased rates of many illnesses ( [[#Hales--2000|Hales et al., 2000]] ; [[#Nitschke--2011|Nitschke et al., 2011]] ; [[#Lu--2020|Lu et al., 2020]] ). Between 1991 and 2011 it is estimated that 35–36% of heat-related mortality in Brisbane, Sydney and Melbourne was attributable to climate change, amounting to about 106 deaths a year on average over the study period ( [[#Vicedo-Cabrera--2021|Vicedo-Cabrera et al., 2021]] ). Exposure to high temperatures at work is common in Australia, and the health consequences may include more accidents, acute heat stroke and chronic disease ( [[#Kjellstrom--2016|Kjellstrom et al., 2016]] ). Long-term rise in temperatures is changing the balance of summer and winter mortality in Australia ( [[#Hanigan--2021|Hanigan et al., 2021]] ). The Black Summer wildfires in Australia in 2019/2020 (Box 11.1) caused 33 deaths directly ( [[#Davey--2020|Davey and Sarre, 2020]] ) and exposed millions of people to heavy particulate pollution ( [[#Vardoulakis--2020|Vardoulakis et al., 2020]] ). In the Australian states most heavily affected by the fires, 417 deaths, 3151 hospital admissions for cardiovascular or respiratory conditions and about 1300 emergency department presentations for asthma are attributed to wildfire smoke exposure ( [[#Borchers%20Arriagada--2020|Borchers Arriagada et al., 2020]] ). Immediate smoke-related health costs from the 2019–2020 fires are estimated at AUD$1.95 billion ( [[#Johnston--2020|Johnston et al., 2020]] ).

Extreme heat is associated with decreased mental well-being, more marked in women than men ( [[#Ding--2016|Ding et al., 2016]] ). Changing climatic patterns in western Australia have undermined farmers’ sense of identity and place, heightened anxiety and increased self-perceived risks of depression and suicide ( [[#Ellis--2017|Ellis and Albrecht, 2017]] ). Following the Black Saturday wildfires in Victoria in 2009, 10–15% of the population in the most severely affected areas reported persistent fire-related post-traumatic stress disorder, depression and psychological distress ( [[#Bryant--2014|Bryant et al., 2014]] ). Repeated exposure to the threat of wildfires in Australia, either directly (Box 11.1) or through media coverage ( [[#Looi--2020|Looi et al., 2020]] ), may compound effects on mental health. In March 2017, 31,000 people in New South Wales and Queensland were displaced by Tropical Cyclone Debbie. Six months post-cyclone, adverse mental health outcomes were more common among those whose access to health and social care was disrupted ( [[#King--2020|King et al., 2020]] ).

Dengue fever remains a threat in northern Australia and variations in rainfall and temperature are related to disease outbreaks and patterns of spread, although most outbreaks are sparked by travellers bringing the virus into the country ( [[#Bannister-Tyrrell--2013|Bannister-Tyrrell et al., 2013]] ; [[#Hall--2021|Hall et al., 2021]] ). Cases of dengue fever and other arboviral diseases have been increasing among recent arrivals to New Zealand from overseas, but to date there have been no reports of local transmission ( [[#Ammar--2021|Ammar et al., 2021]] ).

In 2016 in New Zealand, it is estimated 6000 to 8000 people became ill due to contamination of the Havelock North water supply with the bacteria ''Campylobacter'' ( [[#Gilpin--2020|Gilpin et al., 2020]] ). The infection was traced to sheep faeces washed into the underground aquifer that feeds the town’s (untreated) water supply after an extraordinarily heavy rainfall event. This is not an isolated finding: increases in paediatric hospital admissions are seen across New Zealand two days after heavy rainfall events ( [[#Lai--2020|Lai et al., 2020]] ).

<div id="11.3.6.2" class="h3-container"></div>

<span id="projected-impacts-8"></span>