Forty years ago, a reactor exploded in the Chornobyl Nuclear Power Plant in what was then the Soviet Republic of Ukraine. At least 30 people were killed in the immediate aftermath. The large amounts of radioactive particles released as a result of the explosion travelled in clouds across Ukraine, Belarus and Russia and then spread to other parts of Europe.

It is estimated that tens of thousands have died since then due to radioactive exposure that triggered lethal diseases, including cancer. The frequency of birth defects increased between 200 and 250 percent in affected areas. Hundreds of thousands of people were forced to abandon their homes.

Chornobyl is not history. It is a lived reality of radioactive contaminated land that cannot be farmed, homes that cannot be returned to, thousands of people with lasting health impacts, and costs that continue to mount across generations.

The lesson is clear. When nuclear systems fail, the consequences are long-lasting, widespread, and extraordinarily difficult to manage. The damage does not end when headlines fade. Today, that lesson is no longer confined to accidents. It is being amplified by acts of war.

On the 40th anniversary of the Chornobyl disaster, the world faces another risk of a nuclear disaster as nuclear sites in Ukraine and Iran are threatened.

In Ukraine, there has been continuous military activity near nuclear sites, such as attacks on the electricity grid, the illegal occupation of the Zaporizhzhia Nuclear Power Plant and recent damage to the New Safe Confinement structure caused by the Russian drone attack at Chornobyl.

In Iran, multiple nuclear sites have been repeatedly bombed. The International Atomic Energy Agency has also confirmed that US-Israeli strikes hit within 75 metres of the Bushehr Nuclear Power Plant.

At the same time, the war on Iran has exposed the fragility of the global fossil fuel system, just as the Russian invasion of Ukraine did in 2022. Disruptions to key global trade routes such as the Strait of Hormuz have sent oil and gas prices soaring, driving up the cost of transport, food and energy for millions of households all over the world that are already dealing with a prolonged cost-of-living crisis. No one should be forced to pay higher bills because of a war they have nothing to do with, yet this is precisely how fossil fuel markets operate.

These are not separate crises. They point to the same structural problem.

Both nuclear and fossil fuel systems concentrate risk in large, centralised infrastructure. In a world defined by geopolitical tension, extreme weather and economic volatility, the risk is almost impossible to contain. Nuclear plants and centralised electricity systems are targets of war. Oil and gas supplies can be disrupted at strategic chokepoints. In both cases, the consequences are global.

And in both cases, humanity bears the cost. But there is an alternative.

In war and peace, decentralised renewable energy with storage offers a path to greater resilience, stability, independence and real energy security. It reduces exposure to geopolitical shocks, limits the ability of energy systems to be weaponised, and strengthens the capacity of communities to withstand crises.

Since the start of Russia’s full-scale invasion, decentralised solar and battery systems have helped keep hospitals, schools and critical services running across Ukraine during repeated attacks on the energy grid. These systems are faster to deploy, easier to repair and harder to disable. When one part fails, others continue to operate.

Renewable energy does not rely on fuel that must pass through contested shipping lanes or pipelines. It cannot be blockaded or weaponised for political leverage. The sun and wind are not controlled by any state or corporation. They do not generate windfall profits from conflict, nor do they expose households to sudden price shocks driven by global events.

Importantly, if a renewable energy installation is targeted, it does not result in an environmental and human disaster.

As we mark the 40th anniversary of the Chornobyl disaster, it is important to reflect on its lasting radioactive legacy, but also on ways to avoid its repetition. In today’s increasingly unstable world, the risks of centralised energy systems have multiplied. At the same time, the alternative has moved from theoretical to proven. The question is whether we choose to keep building systems that amplify risks or commit to investing in systems that reduce them.

The views expressed in this article are the authors’ own and do not necessarily reflect Al Jazeera’s editorial stance.