There may be a range of health impacts from changing climate conditions in NSW.

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Hot weather and heat waves

Hot weather and heat waves can have a big impact on people’s health. During hot weather it is easy to get dehydrated. Some people can get more severe health effects, such as heat exhaustion and heat stress, or even die from extreme heat. Heat can also worsen existing health problems, such as heart and lung disease. Generally during heat waves, more people are admitted to hospital and more people die compared with more moderate temperatures.

Big cities like Sydney, Newcastle and Wollongong can trap the heat during the warmer months and lead to the ‘urban heat island effect’. This means temperatures in the cities can be much higher than in surrounding rural areas. This is usually more obvious during the night. Hot nights can make it harder for people to cope with hot weather and can cause stress on health. For more information, please visit Beat the Heat.

Natural disasters and extreme weather events

Climate change may lead to more severe and more frequent storms (hailstorms and tropical cyclones), flash flooding, bushfires and droughts. Extreme weather and natural disasters can worsen people’s illnesses and lead to injuries and death. People may have difficulty accessing health care and getting prescription medicines, clean water supplies may be disrupted, loss of power might lead to spoiling of refrigerated foods, and fresh food may not be available.

Natural disasters can often bring about mental health effects, such as post-traumatic stress. Communities that live or work in exposed regions may be at more risk. In the past, longer droughts have impacted farming communities who experienced lower income, higher workloads, psychological distress including anxiety and depression, and social disruption. Migration or re-location of communities can also cause stress and loss of a sense of belonging. For more information please visit emergency preparedness and mental health impacts and emergency preparedness for natural disasters and severe weather.

Air-borne allergens and air pollutants

Warmer weather and milder winters can increase pollen production. Pollen is an air-borne allergen that can cause allergic responses like hay fever, and may worsen asthma. Air pollutants like ozone and particulate matter are also likely to rise with higher temperatures. Ozone and particulate matter can worsen coughing and cardiovascular diseases and reduce lung capacity. This may cause emergency room visits, hospitalisation or even death. For more information, please visit air pollution and the Australian Society of Clinical Immunology and Allergy.

Food quality and quantity

Extreme weather events, higher temperatures and changing precipitation could reduce local food yields and food quality. Less food production will increase prices of food which can lower people’s access to nutrition. This may affect lower socio-economic and remote communities in NSW more, where there are often restricted food choices. In turn, people with less nutrition may become more prone to disease. For more information on impacts of climate change on agriculture, please visit NSW Department of Primary Industries.

Food-borne diseases

Food may be contaminated by pathogens like viruses, bacteria and parasites. Many pathogens multiply more easily in high temperatures, so increasing temperatures are expected to cause more food-borne diseases. There are already high rates of gastroenteritis in NSW during the summer. Gastroenteritis causes many days off work, doctor visits and hospitalisations in Australia. Food-borne diseases also increase with extreme events, for example power outages can prevent refrigeration and cause foods to spoil. For more information please visit foodborne and gastrointestinal diseases.

Drinking water quality and water-borne diseases

Drinking water quality is affected by many factors. Soil erosion and salinity (the amount of salt in water) can lower water quality. Heavy rainfall and floods can cause sewage overflows, contaminate drinking water supplies and cause disease outbreaks. Droughts can increase some pathogens in water and make it more difficult for water supply authorities to control contamination. Drought and hot weather can also increase cyanobacteria (blue-green algae) blooms in waterways and dams, which can be toxic to humans. For more information, please visit drinking water quality, waterborne diseases and cyanobacteria.

Vector-borne diseases

Changing rainfall, humidity and temperature may lengthen the transmission seasons and change the geographic range of some vector-borne diseases. For example build-up of water from rainfall can become mosquito breeding sites, and warmer temperatures can accelerate growth of viruses in mosquitoes. In Australia, vector-borne diseases such as Ross River virus and Dengue may change geographically and increase in activity. For example, Dengue may extend from Queensland to Northern NSW. However it is more likely that globalisation and population changes, like the movement of people and/or cargo, affects the spread of vectors rather than climate change. Overall, the ecology of vector-borne diseases is complex and difficult to predict. For more information, please visit vector-borne diseases and surveillance.

Current as at: Thursday 13 January 2022
Contact page owner: Environmental Health