What Is Climate Change?

Earth Hour - WWF

The climate of a region is its average or typical weather over a period of time. While we may get a cool day in summer, or a warm day in winter, the climate is the long-term picture of conditions.

Kosciuszko National Park, New South Wales. © Gavin Owen / WWF-Aus

Earth’s climate has changed throughout the planet’s 4.5-billion-year history. During this time, conditions have become warmer or cooler at various periods.
Scientific observations show that Earth’s climate has rapidly changed in the last 100 years. The average Australian temperature has climbed to around 1 °C higher. While it might not seem like much, even a slight change can have major impacts on Earth’s delicate balance of ecosystems. With such a rapid change, it doesn’t leave enough time for plants, animals and humans to adapt.

Major causes of climate change

A coal fired power station in Queensland, Australia. © WWF / James Morgan

Human activities, like burning fossil fuels, deforestation and agricultural production are the major cause of climate change. The burning of fossil fuels like oil, gas and coal release carbon dioxide (CO2) which accumulates in the Earth’s atmosphere. Deforestation also releases CO2 as well as reduces the number of trees that are able to absorb excess CO2.
The increase in CO2 and other greenhouse gases make it more difficult for the solar radiation that hits Earth to escape, trapping the heat and raising the overall temperature of the planet’s surface. While the greenhouse effect at natural levels keeps Earth warm and habitable,  too much of the greenhouse effect, intensified by human activity, causes the Earth to overheat. This is known as the enhanced greenhouse effect.

Impacts of a warming climate

Drought impact.

The planet’s various regions are not all experiencing the same effects of Earth’s temperature rise at the same time. Many regions are experiencing extreme and unpredictable weather, with some becoming hotter and others becoming colder, wetter or drier.
Scientists have projected that our climate could heat up to as much as 6 °C by the end of the century if carbon emissions aren’t cut back. This increase can break down fragile ecosystems and crucial food chains, and result in widespread rainforest destruction, dramatic sea level rises and greatly increased melting of ice sheets in Greenland and the Antarctic.
This would mean severe suffering for humans and other life on the planet.

• Wildlife: Our Earth’s unique wildlife depend on intricate and complex ecosystems to survive. That’s why even a small change to the planet’s climate can disturb nature’s balance and threaten their existence.
• People: Humans rely heavily on the natural environment. It provides us life - from the food we harvest and eat, the air we breathe, the water we drink and the everyday products that we consume. Sadly, climate change will impact the poorest and most vulnerable people that contribute the least to global warming.
  
• Ecosystems: Even the smallest change to temperature and rainfall can be damaging for our delicate ecosystems. It can impact the pollination of flowers, change the hibernation and migration patterns of animals and disrupt entire food chains.
  
• Food and Farming: Increasing droughts, longer and more frequent heatwaves, flooding and extreme weather events due to climate change will make it more difficult for farmers to grow crops and graze livestock. This means that the supply of produce will become limited and prices will rise at supermarkets.
  
• Water: With severe droughts and reduced rainfall, we may see shortages to freshwater supplies.
  
• Coastal Erosion: As the Earth continues to warm, ice sheets will melt, causing sea levels to rise dramatically. This will affect coastlines across the globe, causing erosion and residential damage.
  
• Health: The severity of heatwaves may lead to illness and death, especially among the elderly and vulnerable communities. It can also lead to more mosquito-borne diseases due to higher temperatures and increased humidity.
  
• Coral bleaching: Higher ocean temperatures will impact coral reefs and can cause major coral bleaching events like the ones in 2016 and 2017 that destroyed more than one-third of the Great Barrier Reef.

Working for change

Wind farm, Albany, Western Australia. © Lawrence Murray / WWF-Aus

WWF understands that climate change poses a fundamental threat to species and people’s livelihoods. We advocate solutions to reduce our carbon emissions and slow down climate change – like switching to renewable energy including solar and wind.

WWF-Australia is committed to:

• Limiting global warming to 1.5 °C above pre-industrial levels by the end of the century
• Achieving a net-zero carbon economy in Australia before 2050
• Achieving 100% renewable energy in Australia before 2050, including 100% renewable electricity before 2035.

Links

• What Is Climate Change? The Definition, Causes And Effects
• Climate Change: How Do We Know?
• This Anxiety-Inducing Video Shows More Than 100 Years Of Climate Change In 20 Seconds
• Climate-Change Effects You Might Not Have Considered
• Climate Change, Explained
• Climate Change Is Affecting All Life On Earth – And That’s Not Good News For Humanity
• Australia Experiencing More Extreme Fire Weather, Hotter Days As Climate Changes