Imagine a world where fossil fuels vanish overnight, not gradually phased out, but gone, by Net Zero taken to its "logical" conclusion, as the Greens want. No more coal, oil, or natural gas for electricity, heating, transport, or industry. What happens to daily life in the United States, where brutal winters demand reliable heat, and in Australia, where scorching summers push air-conditioning to the limit? The contrast is stark: one nation freezes in the dark, the other sweats under blackouts. This isn't science fiction; it's a thought experiment on energy dependence, grid resilience, and the brutal physics of weather extremes; an acid test of Zero Net, or Net Zero, whatever poison one prefers.
America's Deep Freeze: The Winter without Natural Gas
In the US, winter is no joke. Sub-zero temperatures, polar vortexes, and ice storms regularly test infrastructure. Right now, natural gas dominates: it provides about 43% of electricity generation and heats roughly 47% of homes directly (with electricity heating another 42%, often backed by gas plants). During cold snaps, demand spikes simultaneously for home heating and power generation, creating "coincident peak" chaos.
Strip away fossil fuels, and the picture darkens fast. Natural gas pipelines freeze, wells ice over, and production plummets (as seen in storms like Uri in 2021 or Elliott in 2022, where gas failures caused massive outages). Coal and oil backups would also be gone. Renewables — wind, solar, hydro — would struggle: solar output drops in short winter days, wind can be unreliable in calm cold fronts, and hydro reservoirs may be low.
Reports from NERC and the Department of Energy warn of elevated blackout risks in extreme cold, even with current mixes. Without fossil fuels, scenarios show outage hours surging dramatically, potentially from single digits today to hundreds per year by the 2030s if firm capacity isn't replaced fast enough. In the Northeast (PJM, ISO-NE), where gas pipelines are already constrained and home heating priority diverts fuel from plants, millions could face prolonged blackouts. No heat means frozen pipes, carbon monoxide deaths from desperate alternatives (generators indoors, fireplaces), and hospitals overwhelmed.
The economy grinds: factories idle, data centres (AI boom included) falter, transport halts without diesel backups. Even with massive battery storage and overbuilt renewables, the intermittency gap in deep winter, when demand peaks and variable sources dip, leaves a reliability chasm. America without fossils? A nation shivering in the dark, rationing blankets, and questioning every thermostat setting.
Australia's Scorching Summer: The Heatwave without Coal and Gas
Flip to the southern hemisphere, and the problem inverts. Australia faces brutal heatwaves, with temperatures soaring past 40°C and humidity turning cities into ovens. Air-conditioning demand explodes, pushing electricity peaks to record highs.
Australia's grid has been transitioning hard: in recent quarters, renewables (solar + wind + storage) exceeded 50% of supply in the NEM (eastern states), with rooftop solar alone covering huge daytime chunks. During the latest heatwaves, solar met 30-59% of demand midday, batteries discharged to cover evenings, and the grid held, despite record demand. Coal output hit lows, gas dipped, yet no widespread blackouts.
Without any fossil fuels? The transition looks more feasible here than in the US winter case. Rooftop solar pairs perfectly with daytime AC spikes, wind often blows in hot afternoons/evenings, and batteries/hydro pump storage can shift energy. South Australia already hits 75%+ renewables annually and eyes 100% net soon. Peaks get met by distributed solar reducing grid strain, with utility batteries tripling discharge in high-demand periods.
But challenges remain: evening ramps after sunset, prolonged cloudy/hot spells reducing solar, and transmission bottlenecks. Gas currently "firms" the grid for those gaps; without it (or rapid hydro/battery/nuclear scale-up), some blackouts or load-shedding could hit during multi-day extremes. Still, the physics favour renewables more in Australia's summer: peak demand aligns with peak solar, unlike US winter's mismatch. Bills could even drop long-term as cheap renewables dominate.
The Global Contrast and the Real Lesson
In a sudden no-fossil world:
America faces existential winter risk: heating fails, grids buckle, lives are lost to cold. Firm, dispatchable power (currently fossil-heavy) is irreplaceable without massive overbuilds of storage, nuclear, or geothermal.
Australia faces summer stress but better adaptation potential: solar abundance matches cooling needs.
This asymmetry highlights energy geography: cold climates demand always-on baseload or vast storage; hot ones benefit from time-of-use alignment with solar. But neither escapes the truth — fossil fuels provide density and reliability that renewables alone struggle to match at scale yet. Abrupt removal amplifies vulnerabilities: blackouts kill in both extremes, whether from hypothermia or heatstroke.
Fossil fuels must remain for energy security far into the future!