Australia is Drying Out and Losing Rainfall Due to Manmade Greenhouse Gases

There's a reason that Australia is slowly drying out, and it might just have to do with greenhouse gases. Scientists have used a new high-resolution climate model to show that southwestern Australia's long-term decline in rainfall is caused by increases in manmade greenhouse gas emissions and ozone depletion.

In order to more closely examine what was happening to rainfall, the researchers conducted several climate simulations with the new model they developed in different regions across the globe. One of the most striking changes occurred over Australia, where a long-term decline in fall and winter rainfall has been observed over parts of southern Australia.

"This new high-resolution climate model is able to simulate regional-scale precipitations with considerably improved accuracy compared to previous generation models," said Tom Delworth, a research scientist who helped develop the new model, in a news release. "This model is a major step forward in our effort to improve the prediction of regional climate change, particularly involving water resources."

More specifically, the new model revealed that greenhouse gases were to blame for these rainfall changes. The scientists simulated natural and manmade climate drivers to show that the rainfall was indeed responding to manmade gases and ozone thinning.

The model didn't just show this trend, though. It showed what might be in store for Australia for the future. It projected a continued decline in winter rainfall throughout the rest of the 21^st century, with significant implications for regional water sources. In fact, southwest Australia is forecast to experience a 40 percent decline in average rainfall by the late 21^st century.

"Predicting potential future changes in water resources, including drought, are an immense societal challenge," said Delworth. "This new climate model will help us more accurately and quickly provide resource planners with environmental intelligence at the regional level. The study of Australian drought helps to validate this new model, and thus builds confidence in this model for ongoing studies of North American drought."

The findings are published in the journal Nature Geoscience.