Impacts of Climate Change

The global average temperature has risen 1.1°C since 1910. In Australia, the average rise is a little over 1.4°C.

In 2019, Australia had both the driest and the hottest year on record. The impacts of extreme heat on plants, coral reefs, animals and people (particularly at-risk people; the young, elderly, and suffers of chronic disease) is becoming ever more visible. In Central Australia and the Northern Territory many trees, including river species and mangroves are dying, along with smaller plants, birds and animals. Coral reefs are dying in warmer waters. It is not well known that many more people have died in the heatwaves before and after major bushfires in recent years than in the fires themselves.

A recent set of annual temperature maps assembled from long-term records by the Bureau of Meteorology illustrates Australia’s temperatures since 1910, with dramatic reds of temperature upswings saturating the maps of recent years.

Considering the impacts of climate change globally, the United Nations Environment Program has stated ‘these record temperatures, heatwaves and droughts are not anomalous, they are the beginning of a new norm.’ Without measures to reduce climate change, heatwaves and drought will continue to become more extreme.

From late 2019 to early 2020, fires burnt across most of Australia with such an intensity, extent and duration not previously experienced. The fires were devastating to people, animals, birds, to insects, to habitats, homes, sacred sites and infrastructure. Permanently ‘wet’ forests that usually suppress fires burnt for the first time.

Trying to make sense of the bushfires —understanding their causes, figuring out how to best respond, are urgent questions that need answers. Across Australia, everyone was impacted: whether we were involved intensely at the fire front, were anxious for family and friends, embarking on the long road of rebuilding, or grieving the loss of people, wildlife, places and the senses of security we once had.

Fire has always been a part of the Australian landscape. But the deepening concern for many of us is the knowledge that more frequent, extreme and widespread fires are an integral part of our now climate-changed Australia. Across much of the continent we are living in hotter, drier landscapes, breathing in the dangerously polluted atmosphere and experiencing the longer, more intense fire season that climate scientists have long been warning us about.

There is deep knowledge, based on extremely careful and long-term research in Australia and around the world, about the ways human-induced climate change is extending and intensifying the Australian bushfire season. The UN Environment Programme (UNEP) recently stated: ‘The huge wildfires in Australia, Amazon, California, the Congo basin and Indonesia have drawn the world’s attention to the risks associated with extended periods of unusually hot and dry weather, which is an effect of climate change.’

The global average temperature has risen 1.1°C since 1910. In Australia higher temperatures create drier conditions, and this increases the ‘likelihood and intensity of wildfires, and megafires.’

Cultural burning

First Nations groups are raising awareness of the benefits of cultural approaches to controlling fire and caring for the land and continuing the practice of cultural responsibility. Low-intensity burns, carried out with detailed knowledge of a place, support vegetation and wildlife and are able to reduce the scale of bushfires, ensuring less damage, less carbon released into the atmosphere. Cultural burning is part of a complete system of care of country.

As described by Koori Country Firesticks Aboriginal Corporation: “cultural burning involves applying fire to the bush in a controlled and methodical approach where the fire acts like water in trickling through the country. It moves slow and ‘cool’ and burns in a circular pattern away from single ignition points.

"A cool fire preserves the canopy of trees that provide shade, fruit, flowers, and seeds. During the fire the insects and other small animals can crawl up the trees to safety, while ants and snakes can retreat down into their nests"

Drought is a long period of time, years, with low to no rainfall. Since weather records began in the late 1800s, Australia has experienced a few episodes of extreme drought: the Federation drought, World War II drought and the Millennium drought. As climate change progresses, it makes drought conditions worse in Australia. Climate models for Australia predict there will be less and less rainfall over most of southern Australia under climate change. The research from CSIRO and the Bureau of Meteorology shows precipitation (rain and snow) could reduce by 50% (that is, we could have half the rain and snowfall as we do now) in winter over southwestern Australia by 2090 if global greenhouse gas emissions aren’t reduced. The CSIRO say the continued decline in precipitation is expected to make droughts more frequent and more severe over Southern Australia.

During droughts fresh water supplies dwindle, which doesn’t just affect us but all living things that need fresh water. And the impacts aren’t just on the environment. People who work in agriculture depend on the land to grow crops or to raise animals. Without water, the industry struggles. The risk of suicide also increases in rural Australia as the severity of drought increases.

There are many farming groups in Australia that work with organisations such as CSIRO to evolve and share knowledge about smart farming methods in times of drought.

We experience weather and all its variables everyday but extreme weather events such as cyclones, heatwaves or floods are less common. These events are rare enough for us not to be resilient to them, but this just means we are vulnerable when they do happen.

As the world warms, seemingly small increases in global temperature change the frequency, intensity, spread, duration, and timing of weather and climate extremes. This already comes at a significant social, environmental and economic cost. Unprecedented extremes affect our physiology and push the thresholds of our socio-economic and human health systems.

Heatwaves are Australia’s deadliest natural hazard and heat-related deaths will only increase as heatwaves get worse under climate change. Australia’s heatwaves are already so severe that they can melt roads and turn vegetation black.

Under current global climate change projections, sea levels will rise anywhere between 45 and 82 cm by 2090. If land-based ice sheets—like the one covering Antarctica—melt, then this level will be even higher. It may not sound like much, but with most of Australia’s population living along the coast this will have a huge impact on coastal infrastructure, community livelihoods, agriculture and habitability. It puts mangrove forests and low-lying freshwater wetlands at risk. And it means people, infrastructure and water resources further inland will also be affected—encroaching sea-levels bring extreme high sea-level events like storm surges, flooding and erosion.

Australia is home to the world-famous Great Barrier Reef on the country’s east coast, and Ningaloo Reef on the west. These reefs are made of corals—animals that are hosts to tiny, colourful marine algae called zooxanthellae. The zooxanthellae give corals their colour and are their primary source of energy.

Climate change causes unusually hot summer sea-surface temperatures, which causes corals to bleach. This is when the coral gets so stressed it expels its algae. The coral tissue then becomes transparent, exposing the white coral skeleton. If sea temperatures drop within weeks to months, then the coral can survive and attract zooxanthellae again. But the longer the bleaching, the more the coral is likely to die.

In 2019 the Great Barrier Reef Marine Park Authority said “Climate change is the greatest threat to the Great Barrier Reef and coral reefs worldwide.” In the past five years, the Great Barrier Reef has suffered from mass bleaching three times—in 2016, 2017 and 2020. The corals of Western Australian reefs are usually more heat resistant but they too suffered their worst mass bleaching in 2016, and some of these reefs now have the lowest coral cover on record.

Bleaching events are occurring more often than ever before, which gives corals very little time to recover from bleaching, if at all.

Life on Earth depends not only on healthy ecosystems but on rich biodiversity. Climate change affects key habitats, which in turn affects the species that live there. To survive, living things across land and sea need to adapt or migrate to more suitable areas. But it’s not always possible to migrate. There might be geographical or human-made barriers or competition from species already in an area.

An ecosystem needs a diversity of species. A balance of species helps ecosystem functions like nutrient cycling, plant pollination and pest control. Ecosystems are inter-connected, so losing even just one species from an area will affect other species and ecosystem functions.

As climate change progresses, and as extremes such as bushfires and marine heatwaves become more frequent and intense, entire ecosystems can be pushed to their tipping points. West Australian kelp forests were wiped out by a heatwave that stretched 100km along the coast in 2011. As the kelp disappeared, so too did the temperate fish, seaweed and invertebrate communities that lived there. Now the ecosystem is more subtropical and tropical reef communities.

The impacts of climate change include more frequent extreme weather like bushfires, heatwaves, storms and cyclones. Not only are property, crops and infrastructure lost, so too are lives. Often, it’s the poor and vulnerable members of society who are likely to be hit the hardest from these events. Those who can’t afford to cool their house, don’t have a place to live, who aren’t able to move, or who can’t access refuges such as shopping centres, libraries and emergency shelters.

Most of the Australian population (about 90%) lives along the coast. And it is here where extreme events are likely to overlap, or ‘compound’. For example, a tropical cyclone comes with intense rainfall, storm surges and flooding. But Australia has regional, rural and outback communities too.

Building resilience and adapting as a community to climate change in any of these areas means protecting the most vulnerable. The National Climate Change Adaptation Research Facility recommends:

• Sharing and devolving responsibility
• Finding effective ways to inform and engage the community to build resilience
• Keep the most vulnerable safe
• Invest in existing networks and infrastructure to build community resilience
• Understand recovery time

The impacts of climate change on human health and wellbeing are deep and wide-ranging.

A large part of our physical health is dependent on the quality of our environment– the temperature, the amount of pollution in our air, water and the nutritional capacity of our soils.

Caring for our environment is caring for our life support system. The more rapidly we transition to renewable fuels for energy and transport in Australia the more rapidly we will improve the quality of the air we breathe and slow the warming of air, land and water masses, all of which supports the health of people and ecosystems.

Impacts on physical and mental health

There are many climate change impacts on health, including injuries and fatalities due to heat, severe storms, cyclones, floods and bushfires, increases in allergies and widespread mental health problems from the wear and tear of the many challenges that climate change presents. There is the loss of the things people care about; loss of sacred spaces and other places of significance for all, including the Great Barrier Reef. There is also the erosion and submerging of coastal lands and islands (and the connection to ancestors, senses of self and belonging that reside in that land), loss of livelihoods due to severe weather, droughts and disasters, and many worries about the future. These, with other impacts, are increasingly leading to ‘climate anxiety’, grief and depression across Australia. Mental health organisations are supporting children, young adults and adults to manage these conditions.

Heat

Temperatures have been rising steadily in Australia each of the last seven years has been the hottest on record. Heatwaves in Australia kill more people than all other natural disasters (fires, cyclones, storms, floods) combined. More than 1000 people over the age of 65 die each year in heatwaves. In urban spaces, planting trees reduces the temperature of houses, streets and shared spaces – as well as absorbing more CO2, helping to reduce heat in the longer term.

Air quality

In Australia, air pollution is the cause of twice as many premature deaths as those from car accidents. This pollution is largely from the combustion of fossil fuels (coal, oil, gas) for power and emissions from cars.

Doctors for the Environment Australia state: ‘If we reduce air pollution levels, there is strong evidence that we can reduce illness and death from stroke, heart disease, lung cancer, and respiratory diseases, such as asthma.’ Stopping the burning of fossil fuels will slow climate change, bringing huge health impacts for all communities.

New diseases

We are likely to see a spread in infectious diseases as species carrying diseases move from their usual range to new areas (such as the anopheles mosquito, which bears malaria and dengue fever). Also, disease spreads as humans, finding food and land resources stretched, push into and start consuming the animals and plants, water, timber, land and other resources in previously untouched habitats, opening up access to previously unexperienced zoonotic diseases – such as COVID-19.

Health and environment ‘co-benefits’ from taking action

The Doctors for the Environment Fact Sheet ‘Climate change and health’ includes more information about all of these impacts, and also explains the excellent ‘co-benefits’ of taking action to reduce climate change impacts through measures such as reducing fossil fuel emissions, which also reduces respiratory illness and deaths due to air pollution. Eating less red meat and using cars less have clear co-benefits for the environment and for human health. Planting trees in urban spaces absorbs CO2 and reduces dangerous heat islands. And, naturally, protecting ecosystems supports carbon sequestration as well as air and water quality, biodiversity and mental health.

Further Reading

For more information about the health impacts of climate change, explore the fact sheets produced by Doctors for the Environment Australia.