Thursday 19 May 2022

Professor Steven Sherwood – Chief Investigator – ARC Centre of Excellence for Climate Extremes. Images and video interview available on Dropbox: 

Experts at the ARC Centre of Excellence for Climate Extremes have challenged the concept of a known “carbon budget”, arguing based on new calculations that action on emissions is more like a “climate gamble” with worsening odds as each year of inaction passes.

“Our research calculated the probabilities of meeting the Paris targets of 1.5° and 2.0°” says Centre Chief Investigator Professor Steven Sherwood.

“You’ll often hear that we have a certain number of years left to act on climate change. What our research shows is that it’s more like a climate gamble. If we stopped all human activity contributing to climate change today, we’d still have a 22% chance of exceeding the 1.5° Paris target. If we wait a year, that chance grows. Another year and it grows again. Every year we wait increases our chance of missing the Paris targets and facing more climate change extremes in the future” says Sherwood.

The paper “Probability of committed warming exceeding 1.5◦C and 2.0◦C Paris targets” published in Environmental Research Letters uses world leading modelling to show policy makers and Governments that action now can still make an important and significant difference.

“The problem with the carbon budget idea is that we don’t know exactly how big the budget is and it could run out any time. For Governments and policy makers the climate gamble and continued emissions is like using a pokies machine programmed to give you worsening odds each day” says Sherwood.

“How long do you keep gambling knowing that your odds are getting worse every day? The good news for Governments and policy makers is our research backs acting on emissions now. The idea of a “carbon budget” we can spend up until the last moment is wrong. The sooner we stop gambling on emissions, the safer we will be, and the sooner we can plan for the health and wellbeing of our communities without guessing where the next gamble will take us. Every year matters.”

The research modelled likelihoods for meeting 1.5° and 2.0° if

  • Emissions had stopped in 2020 completely and
  • If emissions stabilised in 2020 and stopped by 2040.

For the second scenario, the research finds a 90% likelihood of passing the 1.5° Paris target and 17% likelihood of passing the Paris 2.0° target.


Sherwood et al 2022 Environ. Res. Lett. 


Professor Steven Sherwood (Sydney, AEST)

Phone +61 2 9385 8960


Associate Professor Alex Sen Gupta (Sydney AEST) – Co-author

Phone +61 2 9385 8951


Jonathan Brown – ARC Centre of Excellence for Climate Extremes

Phone +61 491008719


Editor’s notes:

The ARC Centre of Excellence for Climate Extremes reduces Australia’s economic, social and environmental vulnerability to climate extremes.

We do this by:

  • Developing and leading fundamental climate science
  • Improving the predictions of extreme weather and climate events
  • Fostering collaborative science between 5 of Australia’s leading universities and our partner organisations
  • Training and investing in the climate science leaders of the future
  • Sharing our knowledge with Governments, policymakers, industry and the community

Climate extremes affect many facets of Australian society including health, soil and water, agriculture, infrastructure, energy security and financial security. Our research programs focus on 4 core areas – weather and climate interactions, attribution and risk, drought and ocean extremes. These are all underpinned by our work in climate modelling – improving the models that analyse extremes of the past and predict extremes into the future.

The Centre is funded by the Australian Research Council and our five partner universities – the University of New South Wales, Monash University, the Australian National University, the University of Melbourne, and the University of Tasmania.