As winter deepens and energy markets remain strained, Germany and the United Kingdom are charting fundamentally different courses. Germany, facing the reality of reduced Russian gas supplies and the premature closure of its remaining nuclear plants, is now deliberating a temporary return to coal-fired power generation. The UK, meanwhile, is accelerating its nuclear ambitions, with a new strategy centred on small modular reactors and large-scale plants.
This is not a wholesale return to coal. German officials stress that any reactivation of coal plants would be a short-term emergency measure, subject to strict limits and only until alternative supplies are secured. The country has already reactivated some coal units as a buffer following Russian supply cuts last year. Now, with gas storage levels declining faster than anticipated and wind generation periodically low, the government faces the uncomfortable prospect of relying on coal to keep the lights on.
From a climate perspective, this is troubling. Coal emits roughly twice the carbon dioxide per kilowatt-hour as natural gas. German emissions, already under pressure after several years of stagnation, could increase by between 5 and 10 million tonnes annually if coal is used at maximum capacity through winter. This is not a collapse of the Energiewende but a pragmatic pause. The question is whether the pause becomes a pattern.
The UK’s approach is more consistent. Its energy security strategy, published in April, calls for nuclear to provide up to 25% of electricity by 2050, up from about 15% today. The government has committed to a new large plant at Sizewell C and is funding research into advanced modular reactors. Unlike Germany, which phased out nuclear after Fukushima, the UK sees fission as a low-carbon backstop to intermittent renewables.
But nuclear is not a short-term fix. Sizewell C will not generate power until the 2030s. The UK’s immediate challenges are similar to Germany’s: managing gas dependency and ensuring grid stability. The difference is that the UK has not foreclosed any low-carbon option. It continues to invest in offshore wind, which now supplies over 20% of its electricity, and is expanding interconnection with Europe.
A closer look at the underlying physics reveals why these choices matter. The atmosphere has a finite capacity to absorb carbon dioxide. Each tonne we emit now adds to a cumulative burden that will persist for centuries. The difference between a 5 million tonne increase from German coal and a 5 million tonne decrease from UK nuclear is not just a statistic. It is a measure of how much harder we are making the problem for future generations.
The urgency is not about panic. It is about recognising that the margin for error is shrinking. Global average temperature has already risen 1.2 degrees Celsius above pre-industrial levels. Every tenth of a degree increases the risk of tipping points: ice sheet collapse, Amazon dieback, permafrost thaw. These are not distant possibilities. They are physical processes already underway.
Germany’s coal deliberation is a symptom of a larger dilemma. The energy transition requires not just ambition but also realism. Countries that prematurely retire reliable generation without adequate storage or alternative supply chains will face harsh trade-offs. The UK’s nuclear focus is not a panacea: costs are high, waste remains a challenge, and construction times are long. But it does provide a path that does not rely on fossil fuels.
Both nations must now accelerate the deployment of grid-scale batteries, demand-side response, and hydrogen storage. These technologies can reduce the need for both coal and gas peaking plants. Until they are ready, though, the physical laws of supply and demand will prevail.
The planet does not care about political narratives. It only cares about the cumulative emissions. For Germany, a temporary coal return is a setback. For the UK, a sustained nuclear expansion is a long-term bet. Neither is sufficient alone. What is required is a massive, coordinated global effort to decarbonise electricity, transport, and industry.
We are not doomed. But we are running out of time. The data is clear. The question is whether policymakers will act on it.
