Climate change set to triple drought, bushfires and floods in Australia
Climate change is likely to almost triple the frequency of bushfires, floods and drought in Australia from one event every 17 years to one every 6 years, according to a new paper published in Nature.
The Indian Ocean Dipole is an atmospheric phenomenon that affects Australia’s climate as well as those of other countries on the Indian Ocean and is a significant contributing factor to rainfall variability. Its positive phase usually results in droughts in the eastern Indian Ocean and floods in the western Indian Ocean.
The findings mean not just a rise in the number of droughts and fires in Australia and neighbouring countries in Asia, but also a rise in extreme weather events around the world, including Africa.
This is the first study of the extreme positive Indian Ocean Dipole’s response to climate change, completed using an ensemble of climate models using the highest scenario of greenhouse gas emissions — equivalent to a 4.9°C temperature rise by the end of the century.
Dr Wenju Cai from CSIRO Marine and Atmospheric Research, who led the research, said it’s very important to understand how an extreme positive Indian Ocean Dipole event may respond to climate change because of its global impact.
“Most of our severe bushfires were preconditioned by the Indian Ocean Dipole… When a summer season is preceded by an [extreme positive] Indian Ocean Dipole our bushfires tend to be much more severe,” he said.
“Now this is in Australia, but it has global impact. [For example] in Indonesia, a positive Indian Ocean Dipole tends to cause drought. You may recall in 1997 we had a wild bushfire in Indonesia… emitting a lot of pollutants and smoke that caused health problems to many millions of people in the region and also cost lost economic activity because people couldn’t go out because of the visibility problem.
“In the meantime, in eastern African countries, they experienced devastating floods, causing thousands to die… and displacement of many hundreds of thousands.”