UNSW Canberra-led climate change study highlights the importance of acting now


The link between human-caused climate change and some extreme weather events such as heatwaves has long been established. However, while previous studies have focused only on current extreme events, a UNSW Canberra-led project is looking towards the future.

“Previous studies mainly look at how the last 150-160 years of emissions of greenhouse gases are affecting extremes,” UNSW Canberra Climate Scientist Sophie Lewis said.  

“Our study took a new approach. It is based on the idea that countries are now aware of the potential negative impact of these greenhouse gases, and how they are changing our extreme events.”

It also paves the way for a new line of study: If major emitters are aware of the potential impact their climate change policies will have, could they be held legally responsible for extreme weather events in the future?

The paper, authored by Dr Lewis, Sarah Perkins-Kirkpatrick (UNSW), Glenn Althor (University of Queensland), Andrew King (University of Melbourne) and Luke Kemp (University of Cambridge), was published on Friday by Geophysical Research Letters.

“We looked at how current emissions policies will impact future climate extremes,” Dr Lewis said.

“We focused on China, the European Union and the United States and explored how their current Paris Agreement pledges will impact the occurrence of extreme temperatures in the future.”

Using climate models, the team looked at the contribution of these major emitters’ current policies on future extremes. They found that the likelihood of future temperature extremes depends on the carbon dioxide targets being set by these emitters now. 

“We quantify the contributions of these emitters to future temperature extremes in regions across the globe, and highlight the Central Europe region,” Dr Lewis said.

“As the US is unlikely to meet its Paris pledges, we find that it is almost certain that the US will contribute to future monthly temperature extremes occurring in Central Europe.”

Dr Lewis said there are multiple benefits to major emitters implementing ambitious emissions reductions targets.

“Contributions of emitters to future extremes can be reduced with stronger pledges,” she said.

“For the US, this contribution can be reduced from a virtually certain contribution to a three-times increase in risk for future Central European extremes.”

Dr Lewis said the study focused on the major emitters, but this approach can be applied to all countries, including Australia, as we are not on track to meet our Paris pledges.

“By acting now, major emitters can reduce the likelihood of future extremes occurring in less developed and lower emitting nations. The Paris Agreement matters” she said.

 Assessing contributions of major emitters’ Paris-era decisions to future temperature extremeswas published by Geophysical Research Letters.