CAUSES OF GLOBAL WARMING
What is global warming?
Global warming refers to the long-term increase of the Earth’s surface temperatures caused by the increasing concentration of greenhouse gases in the atmosphere.
When we burn fossil fuels, greenhouse gases are released into the atmosphere, wrapping around the planet like a blanket that traps the Earth’s heat, leading to rising surface temperatures. The greenhouse gases that are the biggest contributors to global warming are carbon dioxide, methane and nitrous oxide, with a significant amount coming from the transportation, manufacturing, construction, agriculture, and oil and gas industries.
Are humans causing global warming?
The science is clear. Human activities have been responsible for nearly all global warming over the past 200 years, primarily by burning fossil fuels such as oil, coal and gas.
Here are some of the numbers:
- Global average carbon dioxide concentrations reached 414.4 parts per million (ppm) in 2021, the highest level in roughly 2 million years.
- The Earth’s average surface temperature has risen by 1.1°C since the late 1800s, with most of the warming happening in the past 40 years.
- A significant portion of the greenhouse gases released into our atmosphere are absorbed by our oceans, making them more acidic. The acidity of surface ocean water has increased by 30% since the early 1800s.
What are the causes of global warming?
A lot of human activities contribute to global warming and climate change to various degrees – here are the biggest contributors:
1. Burning fossil fuels
When we burn fossil fuels like coal and gas to create electricity or power our cars, we release carbon dioxide pollution into the atmosphere.
Australia is one of the world's biggest producers of carbon dioxide pollution, with our carbon dioxide emissions per person nearly double the average of developed nations and more than four times the world average.
In 2022, burning fossil fuels made up 68% of Australia’s total electricity generation, with 47% coming from coal, 19% from gas and 2% from oil. The remaining 32% came from renewable energy sources like hydro, solar and wind, which do not emit carbon.
Methane emitted from coal mines represents 23% of Australia’s total methane emissions, second only to agriculture. However, mitigating emissions within the mining industry is four times cheaper than in the agricultural industry.
Solutions:
- Supporting global calls for a Fossil Fuel Non-Proliferation Treaty and urging the Australian Government to commit to a federal emissions reduction target of at least 90% below 2005 levels by 2035.
- Calling on the Australian Government to stop approving new fossil fuel projects.
- Urging the Australian Government to ensure a fast, best, and just transition to 700% renewable energy production by 2050 and securing our position as a Renewable Exports Superpower.
2. Deforestation
Plants and trees are essential in regulating the climate because they absorb carbon dioxide from the air and release oxygen back into it. Forests and bushland are carbon sinks, storing carbon that, if lost, can’t be restored by 2050. This is also known as irrecoverable carbon. Therefore, if we are to keep global warming to 1.5°C, we must maintain and restore our forests.
But humans clear vast areas of vegetation worldwide for agriculture, urban and infrastructure development, or to sell products such as timber and palm oil. When vegetation is removed or burnt, the stored carbon is released into the atmosphere as carbon dioxide, contributing further to global warming. Up to one-fifth of global greenhouse gas pollution comes from deforestation and forest degradation.
Australia has the highest rate of deforestation in the developed world. The deforestation of Australian forests releases approximately 24 million tonnes of carbon into the atmosphere each year.
Solutions:
- Calling on our leaders to introduce stronger laws that protect and restore trees.
- Planting and protecting more native forests.
3. Agriculture
The greenhouse gases emitted from agriculture are methane, nitrous oxide and carbon dioxide. Livestock like cattle and sheep produce a large amount of methane – making up approximately 10% of Australia’s emissions. Additionally, carbon dioxide released from landclearing is the second largest source of emissions from Australian agriculture.
As the rest of the Australian economy decarbonises, agriculture's share of emissions is expected to increase from 17% in 2022 to over 25% in 2035.
Solutions:
- Choosing financial institutions, supermarkets and timber retailers that support a deforestation-free Australia.
- Asking your local member of parliament to provide funding and financial rewards for farmers who undertake sustainable production.
4. Transportation
Greenhouse gases are emitted from burning fossil fuels for cars, trucks, ships, trains and planes. Transportation currently makes up roughly 24% of global carbon dioxide emissions.
In Australia, our transport sector accounts for close to one-fifth of emissions, with passenger cars and light commercial vehicles contributing 10% of our overall emissions.
Solutions:
- Calling on the Australian Government to increase investment in public transport.
- Supporting the shift to more Electric Vehicles (EV) to reduce emissions and develop new green jobs in Australia.
- Decarbonising our public road transport network through electric-powered buses and trains.
- Increasing the use of low emissions fuels like some biofuels used in internal combustion engines.
5. Industry manufacturing
The goods and services we consume all require energy in the form of electricity and heat to convert raw materials into usable products. In the manufacturing industry, energy is needed to create steel, cement, aluminium, chemicals, food processing and many other materials, such as paper, that we use every day.
The primary energy sources fuelling Australia’s manufacturing industry are coal and renewable energy for electricity and diesel and natural gas for heat processing. Manufacturing and waste are responsible for 14% of Australia’s total direct emissions – that does not include their consumption of electricity, of which they are the largest user. Solutions:
- Building unstoppable momentum to increase renewables and green hydrogen for manufacturing and reduce the upfront and embodied carbon in the building and construction industry.
- Supporting Australia’s transition towards greening iron and steel aluminium, other building materials, chemicals, fuels production and other manufacturing.
What is the difference between global warming and climate change?
While they are often used interchangeably, global warming is just one aspect that contributes to climate change. The increased surface temperature caused by global warming leads to noticeable changes in our climate - not just in warmer land and ocean temperatures. Other changes to the environment include rising sea levels, shrinking glaciers and sea-ice, shifts in plant blooming times and an increase in extreme weather events. This broader range of changes is what we refer to as climate change.
So, while the two terms are related, climate change is an 'umbrella term' that encompasses the broader impacts of global warming.
What WWF is doing
To save the species, places and communities we love, we must do everything possible to keep global warming at 1.5°C above pre-industrial levels. The good news is we have the solutions and opportunities to do this.
It’s not too late. But we must act!
WWF-Australia is dedicated to helping Australia become a global leader in securing a healthy climate powered by communities, nature and renewable energy.
