Experts Warn of Fossil Fuel "Cliffs" Threatening Energy Transition

Researchers say unplanned decline of fossil fuel systems could trigger crises, price shocks, and safety threats before green energy is ready.

Jan. 30, 2026 at 4:15am

Got story updates? Submit your updates here. ›

As the world shifts to renewable energy, experts warn that a lack of planning for the retirement of fossil fuels could lead to a disorderly and dangerous collapse of existing systems that could prolong the transition to green energy. Researchers from the University of Notre Dame introduced the concept of "minimum viable scale," a threshold of production below which a fossil fuel system can no longer function safely or economically. They provided examples of vulnerabilities in three major sectors - petroleum refineries, natural gas pipelines, and coal generation - and argued that the decline of fossil fuels is unlikely to follow a smooth, linear path.

Why it matters

The danger, according to the authors, is that these fossil fuel systems are "networks of networks." If one piece fails - a pipeline, a specialized labor pool or a regulatory body - the entire regional energy support system could dissolve, leading to disruptions in services, price spikes and reliability issues that could undermine public trust in the energy transition and stall progress toward climate goals.

The details

The researchers highlighted several vulnerabilities in major fossil fuel sectors. Petroleum refineries are often incapable of operating normally at low capacity and have "turndown limits" of roughly 65-70% - if gasoline demand drops sharply due to electric vehicle adoption, refineries might be unable to provide other products like jet fuel or asphalt. For natural gas pipelines, as customers switch to electric heating and cooling, those remaining on the gas grid will have to shoulder the fixed costs of maintaining miles of pipelines, creating a "death spiral" where rising costs drive more customers away. In coal generation, the fate of mines and power plants is inextricably linked, so a single plant closure can make a local mine unprofitable, or a mine closure can leave a power plant without its fuel source, leading to a cascade of failures.

  • The study was published in the journal Science in January 2026.

The players

Emily Grubert

Associate professor of sustainable energy policy at the University of Notre Dame's Keough School of Global Affairs and a faculty affiliate of the Keough School's Pulte Institute for Global Development.

Joshua Lappen

A postdoctoral researcher at the Pulte Institute who studies how energy networks grow and shrink over time.

University of Notre Dame

The institution where the researchers who authored the study are based.

Got photos? Submit your photos here. ›

What they’re saying

“Systems designed to be large and growing behave differently when they shrink. Ignoring this shift puts everything at risk, from the success of green energy to the basic safety and reliability of our power.”

— Emily Grubert, Associate professor of sustainable energy policy (Mirage News)

“None of these systems were designed with their own obsolescence in mind. None of the engineers, founding executives, economists or accountants involved ever imagined a system that would gradually and safely hand off to another.”

— Joshua Lappen, Postdoctoral researcher (Mirage News)

“If you are leaving decisions about things staying open or closing to individual operators who are not coordinated in any way, this can be incredibly dangerous.”

— Emily Grubert, Associate professor of sustainable energy policy (Mirage News)

What’s next

The researchers recommended that policymakers and energy modelers develop high-resolution tools to identify when fossil fuel assets reach their minimum viable scale, establish management structures to coordinate decisions across ownership boundaries, have public entities manage unprofitable systems for public need, and create mechanisms to guarantee the payment of long-term liabilities as these systems decline.

The takeaway

Experts warn that the unplanned decline of fossil fuel systems could trigger localized energy crises, price shocks, and safety threats long before renewable energy is ready to fully replace them, potentially undermining public trust in the energy transition and stalling progress toward climate goals. Proactive planning and coordination is needed to manage this complex process.