Facts for students

What causes climate change?

Climate change is caused by an increase in the greenhouse gases in the Earth’s atmosphere. These gases absorb heat leaving the earth and return some of it, making the earth warmer overall.

Before the industrial revolution, carbon dioxide (a greenhouse gas) levels in the atmosphere were consistently between 260 and 280 parts per million (ppm). In recent times human activities have increased the concentration to 380 ppm - that’s an increase of more than a third!

Greenhouse gases are produced during the burning of fossil fuels, by using electricity generated by burning fossil fuels and by other activities, such as some aspects of farming and land clearing.

What are the effects of climate change?

Research by the world’s scientists, including the Intergovernmental Panel on Climate Change, suggests that:

On average, the Earth is warming. Its temperature has already risen by around 0.7°C over the past hundred years, and may rise by between 1.4 and 5.8°C this century.
Sea levels are rising as oceans expand and glaciers and ice sheets melt - by 2100 sea levels may be from 9 to 88 centimetres higher.
Changes in weather patterns, such as more severe droughts, heat waves, floods and storms; changes in rainfall patterns; and higher likelihood of bushfires.
Adverse impacts on plants, animals and human health as climate patterns shift.

Australia is very vulnerable to the impacts of climate change. Globally, the 10 warmest years on record have all occurred since 1990. And 2005 was Australia’s warmest year on record, 1.1°C above the average for the period 1961 to 1990.

Not the ozone hole!

A lot of people think that there is a link between climate change and the hole in the ozone layer. This is not the case. The ozone hole is caused by chemicals combining with the ozone in our atmosphere, leaving less ozone to block out harmful types of radiation from the sun. Some gases, such as chlorofluorocarbons (CFCs), eat up the ozone layer and also add to climate change, but most of the greenhouse gases that cause climate change do not affect the ozone layer.