These FAQs explain more detail about climate change, why it is happening, why we should be concerned, how climate change differs from changes to the weather, and how climate and weather are linked.
Why is our climate getting warmer?
The main reason our climate is getting warmer is because people are adding greenhouse gases to the atmosphere more quickly than in the past.
This causes a thickening of the blanket of greenhouse gases in the upper atmosphere, which in turn traps heat from the sun within it, instead of reflecting back into space. This heat is absorbed by the land and ocean making the planet warmer.
This increase in greenhouse gases and the planet’s surface temperature is happening much more rapidly than at any previous time in the Earth’s history. As population increases there is more demand for infrastructure, goods and services such as housing, heating, cooling, communication and transport. The fossil fuels burnt to create energy for this activity, along with the increasing amounts of land taken over by human activity and the waste we produce along the way, all add to greenhouse gas pollution.
Greenhouse gases have always played a part in Earth’s natural temperature regulation, but this ever growing human activity is putting more pressure on the natural system than it can accommodate. The additional gases can remain trapped in our atmosphere for up to 90 years, with flow-on effects that contribute to long-term global warming.
Enhanced greenhouse effect
Step 1: Solar radiation reaches the Earth's atmosphere - some of this is reflected back into space.
Step 2: The rest of the sun's energy is absorbed by the land and the oceans, heating the Earth.
Step 3: Heat radiates from Earth towards space.
Step 4: Some of this heat is trapped by greenhouse gases in the atmosphere, keeping the Earth warm enough to sustain life.
Step 5: Human activities such as burning fossil fuels, agriculture and land clearing are increasing the amount of greenhouse gases released into the atmosphere.
Step 6: This is trapping extra heat, and causing the Earth's temperature to rise.
© Commonwealth of Australia 2013
Why is a warmer climate bad?
As levels of greenhouse gases rise in the atmosphere and the planet continues to warm, we experience the effects in weather systems, agricultural production, water resources, ecosystems and on human settlements. As oceans warm they expand and ice at the polar caps melts. Less ice means that there is less heat from the sun reflected away from the Earth, so the water absorbs this heat and we end up with an ongoing cycle of rising temperature.
An average temperature rise of 1°C or 2°C may not seem much, but the severity of hotter and colder extremes is having a huge impact on people and planet alike. The last decade has been the hottest on record, interspersed with extremes of cold weather.
We can expect this trend to continue and we will experience more changes in rainfall, winds, bushfire, flooding, coastal inundation, cyclones and drought. These changes will affect our ability to grow food crops, the reliability of transport and communication systems, and our ability to heat and cool our homes. Needless to say, climate changes will also have a financial impact. It’s essential to take action now to adapt to these changes, while we also try to reduce the rate of global warming.
What is the difference between climate and weather?
Climate is the trend over time and weather is what we experience on a daily, weekly or monthly basis. In other words, climate refers to averages, variations and extremes of weather in a region over long periods of time. The usual period for estimating average climate is thirty years or more, long enough to sample a full range of weather (Australian Academy of Science, 2010).
This brief animated video Trends and Variations explains the differences between weather and climate really well.
What can we do about climate change?
Your local Council and this website provides information, action planning tools and ways to get involved with others in your community who are also doing their best to adapt to climate change. You can take action to reduce your own carbon and greenhouse pollution by using renewable energy sources, sustainable transport and products and services that use less carbon to make or deliver.