Climate change and health

Our health is closely linked to the environment we live in. Our climate is now changing, with significant consequences for our health, wellbeing and safety. Climate change is a shift in the world’s weather systems that takes place over decades.

Most of the recent changes in our climate have been brought about by human activity. Without action, the changing climate will have far-reaching consequences for communities and the rest of the world. It is an urgent problem with implications at the global, national, community and personal level.

The good news is that there are simple things we can all do now to build resilience to the effects of climate change and help slow its pace. Many of these actions will also directly benefit our health, the environment and our finances.

What causes climate change?#

Climate change is caused by rising levels of greenhouse gases (such as carbon dioxide, methane and nitrous oxide) in the atmosphere, which cause the earth’s average temperature to rise. Greenhouse gases trap heat in the atmosphere, raising air and sea temperatures. They are produced mainly through the burning of fossil fuels (such as coal) for electricity, as well as through agriculture, mining, land management and transport.

The effects are already being felt. Global average temperatures have risen over the past century. Many regions are experiencing changes such as:

• declining cool-season rainfall and lower streamflow, affecting the health of waterways and water supplies
• more intense extreme rainfall, increasing the risk of flash flooding in some places
• rising coastal sea levels.

Many people live close to the coast. Rising sea levels and storm surges increase the risk of flooding and erosion, endangering life, damaging property and harming ecosystems in ways that can affect agriculture, forestry, fisheries and tourism.

How climate change affects health#

The World Health Organization has described climate change as one of the biggest threats to health of the 21st century. It affects health and wellbeing in several ways:

• directly, through the increased intensity and frequency of extreme weather events (such as heatwaves, floods and wildfires)
• indirectly, through worsening air quality, changes in the spread of infectious diseases, threats to food security and effects on mental health.

Climate change can also affect parts of the economy, with the potential for increased unemployment, financial stress, food insecurity and widening social inequalities.

Who is most at risk?#

Some people are more vulnerable to the health effects of climate change:

• Children are more susceptible to heat stress and dehydration and more sensitive to air pollution and smoke. Their immune systems are not fully developed, putting them at greater risk of infection, and they often depend on adults to keep them safe during emergencies.
• Pregnant women are at increased risk of heat stress during heatwaves because of the physiological demands of pregnancy. They and their unborn babies are particularly sensitive to air pollution and smoke.
• Older people and people with pre-existing medical conditions are more prone to dehydration, heat stress, infections and worsening of heart and lung disease.
• People on low incomes, in rural or remote areas, and other vulnerable groups are also at higher risk, partly due to inequalities in underlying health and limited access to healthcare and other services.

Staying healthy in a changing climate#

There are many simple actions you can take to protect yourself and your family.

Cope and stay safe in extreme heat#

Average temperatures have risen and heatwaves have become longer, hotter and more frequent. You can stay healthy in the heat by:

• drinking plenty of water
• never leaving anyone (or pets) in a parked car
• staying somewhere cool
• planning ahead
• checking in on others.

Protect against mosquito bites#

Warmer temperatures and more frequent flooding can create conditions in which disease-carrying mosquitoes thrive. You can reduce your risk by:

• fitting your home with mosquito netting or screens
• wearing loose-fitting clothing outdoors
• using mosquito repellents containing DEET or picaridin on exposed skin
• limiting outdoor activity when lots of mosquitoes are about
• removing stagnant water around your home where mosquitoes can breed.

Stay safe in water#

Warmer temperatures can increase health risks for swimmers, including exposure to toxins from algal blooms, which are expected to become more frequent. You can lower these risks by:

• checking for water quality advisories after flooding or during blue-green algal blooms
• avoiding swimming at beaches or in waterways after heavy rainfall or floods.

Outbreaks of illness linked to swimming pools may become more common as pools are used more on hot days. To help keep the water clean:

• do not swim if you have had diarrhoea recently
• shower and wash thoroughly before you swim
• wash your hands thoroughly after using the toilet
• avoid swallowing water while swimming
• tell the pool operator if you become ill after swimming.

Be aware of air pollution#

Many factors affect the quality of the air we breathe. Burning fossil fuels releases pollutants such as nitrogen oxides, sulfur dioxide and particulate matter. The interaction of air pollution and sunlight produces ozone. While ozone high in the atmosphere protects us from UV radiation, breathing ozone at ground level can trigger asthma attacks and breathing problems.

Air quality is also harmed by wildfires, which are expected to become more frequent and severe. Climate change may lengthen pollen seasons and increase pollen production in some plants, which can cause allergic reactions such as hay fever. On days of poor air quality:

• check local alerts about wildfires and pollen
• plan or postpone outdoor activities accordingly
• avoid or limit vigorous physical activity
• if you have a pre-existing lung or heart condition (including asthma), take your medication and follow your treatment plan.

Keep food safe#

Higher temperatures increase the risk of food-borne infections such as gastroenteritis, caused by faster growth of pathogens such as Campylobacter, Salmonella and E. coli. Follow good food safety and storage practices, especially in warm weather and outdoors.

Look after your mental health#

Beyond its effects on physical health, climate change can affect mental health. Extreme weather events such as floods, droughts and wildfires can cause psychological distress through trauma, illness, loss of loved ones, destruction of property, displacement and disruption to communities and services. Seeking help and support early can make a big difference to getting the right care for your needs.

Individual action can make a difference#

If we each make changes, together these add up to collective action that makes an even bigger difference. There are many positive things you can do that help slow climate change and also benefit your health:

• Use active transport. Walking and cycling can help reduce your risk of obesity, diabetes, heart disease, some cancers and musculoskeletal conditions.
• Rely less on cars. Using active or public transport reduces greenhouse gas emissions and improves air quality, helping to reduce rates of lung conditions, heart disease and stroke.
• Eat more plant-based foods. A diet rich in fruits, vegetables, nuts, seeds and whole grains, with fewer animal-based foods, is good for your health and the environment. Eating the recommended amount of fruit and vegetables can help you maintain a healthy weight and lower cholesterol and blood pressure.
• Cut back on highly processed foods. These are often high in saturated fat, added sugar or salt, take more energy to produce and are usually packaged, adding to landfill waste.
• Drink tap water. Where tap water is safe, choosing it over bottled water or sugary drinks is better for your health and the environment, and cheaper too.
• Heat and cool your home efficiently. This keeps you comfortable year round, saves energy and reduces demand on the wider system.

These benefits matter not only for the health of our communities but also help reduce demands on the health system.

Key points#

• Climate change is driven largely by human activity raising greenhouse gas levels in the atmosphere.
• It affects health directly through extreme weather and indirectly through air quality, infectious disease, food security and mental health.
• Children, pregnant women, older people and disadvantaged groups are most at risk.
• Simple actions such as staying cool, avoiding mosquito bites, swimming safely and watching air quality help protect your health.
• Active transport, plant-rich diets and efficient energy use benefit both your health and the climate.

Where to get help#