The Australian Academy of Science says man-made climate change is real and the consequences will be dire if no action is taken to address it.
The academy, in an update to its science of climate change booklet produced in 2010, says its authoritative account of the science behind global warming will help counter confusion and misinformation.
The update is written and reviewed by 17 of Australia’s leading experts in a range of climate-related sciences.
Earth’s climate has changed over the past century. The atmosphere and oceans have warmed, sea levels have risen, and glaciers and ice sheets have decreased in size.
The best available evidence, the scientists say, indicates that greenhouse gas emissions from human activities are the main cause.
Continuing increases in greenhouse gases will produce further warming and other changes in Earth’s physical environment and ecosystems.
In Australia, the average surface temperatures over the Australian continent and its surrounding oceans have increased by nearly 1 degree Celsius since the beginning of the 20th century.
Seven of the ten warmest years on record in Australia have occurred since 2002.
However, there are differences across Australia with some regions having warmed faster and others showing relatively little warming.
Since the mid 1990s there have been significant increases in wet season rainfall over northwest Australia, a declining trend in southwest Australia, and a 15% decline in late autumn and early winter rainfall in the southeast.
The reports says future climate change and its effects are hard to predict accurately or in detail, especially at regional and local levels.
Many factors prevent more accurate predictions and uncertainty is likely to remain for considerable time.
However, climate change has impacts on ecosystems, coastal systems, fire regimes, food and water security, health and infrastructure.
The impact will vary from one region to another and, in the short term, can be both positive and negative. In the future, climate change will intensify.
“Societies, including Australia, face choices about how to respond to the consequences of future climate change,” the report says.
“Available strategies include reducing emissions, capturing CO2, adaptation and ‘geoengineering’. These strategies, which can be combined to some extent, carry different levels of environmental risk and different societal consequences.”