What are the observed effects of climate change?
Over the last century, average global temperatures have risen by about 0.74°C2. Observed effects of climate change include changes in average rainfall, increasing risk of droughts and floods, fewer frosts, more heat waves, glacial melting and rising sea levels. These changes in weather patterns could severely diminish our ability to sustain global populations, and threaten the delicate ecosystems of the earth’s plants and animals.
Global Temperature Records1
.jpg)
What are scientists saying about climate change in Australia?
The effects of climate change are already being felt in Australia. Average annual temperatures have increased by about 0.9°C since 19501. Many scientists warn that we can expect these patterns of warming to continue, rising 0.6-1.5°C by 2030 and 1-5°C by 2070, depending on future levels on greenhouse gas emissions3. They have forecast an increase in the frequency of droughts and fires, a greater risk from storms and flooding in coastal areas and a decline in overall agricultural production. There is also a threat to the biodiversity of some of Australia’s rich ecological sites, such as the Great Barrier Reef.
How do we know human activities are contributing to climate change?
Climate changes have occurred throughout earth’s history. However most scientists agree that the current rate of climate change cannot be explained by natural causes alone. The average global temperature is the highest it has been in over 1,000 years and ice-core samples from the Antarctic reveal that the current concentration of CO2 in the atmosphere has not been exceeded in over 650,000 years4. Scientists can only explain the increased rate of warming when human greenhouse gas emissions are included in their computer simulations.