A new modelling tool developed by Australian researchers has revealed a sobering reality achieving urgent climate goals could clash with avoiding a major global energy shortfall.
UniSA Researchers Unveil ‘GREaSE’ Model
Researchers at the University of South Australia have introduced a new open-source energy scenario tool called GREaSE (Global Renewable Energy and Sectoral Electrification), offering fresh insight into the global energy transition dilemma.
Developed by Associate Professor James Hopeward and three civil engineering students Shannon O’Connor, Richard Davis, and Peter Akiki the model explores a range of “what-if” future energy scenarios often left out of mainstream discussions.
“It’s designed to be simple, accessible, and exploratory,” said Assoc Prof Hopeward. “Most climate scenarios either paint a picture of fossil-fueled disaster or a utopia of renewable abundance. But what if the reality lies somewhere in between?”
A Mid-Path with Major Risks
The GREaSE model simulates various trajectories for the world’s energy systems, including rapid fossil fuel cuts, high and low energy demand, and varying levels of electrification. The results reveal a consistent trend across scenarios: the world is heading toward renewable energy whether by design or by default.
“Even if fossil fuels are phased out to meet climate targets, or simply become scarce, we’re still headed toward a renewables-dominated future,” said researcher Richard Davis.
However that transition may not be smooth. The model shows that renewables likely can’t scale fast enough to fill the gap left by rapidly declining fossil fuels, at least not in the short term.
A 20–30 Year Energy Gap Looms
One of the model’s most striking findings is a projected 20 to 30-year gap between global energy demand and renewable supply even under optimistic scenarios.
“By 2050, renewables may meet demand. But until then, we’ll likely face a crunch in supply,” said Shannon O’Connor. “That means we might need to lower our expectations around how much energy will be available to drive our economies during this transition.”
Nuclear Not the Answer
Some may point to nuclear power as a potential stopgap, but the team says that’s unlikely.
“Nuclear can’t be scaled globally at the rate we need, and uranium resources are limited,” said Prof Hopeward. “Even with expanded resources, nuclear builds too slowly to bridge the shortfall before renewables catch up.”
Not a Case for Fossil Fuel Comeback
Despite the short-term energy squeeze, the researchers emphasize their model does not argue for continued fossil fuel reliance. Rather, delaying the transition only means dealing with the same energy transformation later and in a hotter, more unstable climate.
“It’s like being told to eat better and exercise,” said Hopeward. “You can delay the change and risk a heart attack, or start now and deal with the pain early. Our global energy system needs a diet and fast.”
Free Tool to Spark Global Dialogue
The GREaSE model is free, open-source, and designed for both experts and the general public to explore the possible futures of global energy and climate. The developers hope it will spark deeper, more balanced discussions about the real challenges and trade-offs in building a cleaner, reliable energy future.