Bill Gates shocked everyone, a scientist "nailed it": Possible nuclear ice age and death of two billion people

However, experts on existential risks warn that humanity is more likely to destroy itself before climate disasters fully unfold.

According to reports, the greatest danger is a total nuclear war, which could wipe out civilization in just a few hours, the Daily Mail reported.

Gates shocked everyone

Gates’ article was published ahead of the COP30 climate summit in Brazil, where world leaders are expected to discuss the future of the climate.

Gates’ open letter, released before the summit, sparked controversy among scientists and activists, but also received support from those who believe climate panic is exaggerated.

In the open letter addressed to global officials, Gates acknowledges that climate change will affect poor populations the most, but he dismissed apocalyptic scenarios.

“People will be able to live and thrive in most places on Earth in the foreseeable future,” wrote the billionaire, who has invested huge sums through his foundation in green technologies such as renewable energy and resilient agriculture.

This statement represents a sharp shift from his previous warnings about the climate crisis.

This shift also comes at a time when the world is indeed facing extreme weather events, from floods in Europe to droughts in Africa.

Gates now insists that the focus should be on adaptation, which he sees as the key, rather than panic. However, experts only partially agree: climate change may not be the greatest existential risk, but it cannot be ignored.

Nuclear war — the real threat

According to experts on existential risks, one of the threats that could lead to the complete extinction of humanity is nuclear war.

Dr. Rhys Kriley, an international relations expert at the University of Glasgow, explained the key difference in an interview with the Daily Mail.

“Climate change unfolds over decades, whereas a nuclear war could destroy civilization within a few hours. Climate change is a slow-moving crisis that is already reshaping our world and will worsen in the future, but nuclear weapons represent the possibility of immediate, total destruction of the planet,” he said.

This threat is not just theoretical. The arsenals of nuclear powers contain more than 12,000 nuclear warheads, and tensions between countries such as the U.S., Russia, and China are rising.

“These risks are not hypothetical. The weapons exist, tensions between nuclear-armed states are escalating, and it seems these countries are increasingly willing to use force to achieve their goals, while simultaneously threatening the use of nuclear weapons,” Kriley warned.

Scientific models reveal the catastrophic impact

Even a “limited” nuclear conflict involving just 100 warheads — far fewer than what a country like Russia could launch — would trigger a nuclear winter.

The atomic explosions would ignite massive fires, sending plumes of soot and dust into the atmosphere, similar to a supervolcano eruption.

Modern climate models predict that this would block sunlight for years, causing a “minor nuclear ice age.”

Global temperatures could drop by up to 10 °C for at least a decade, devastating agriculture and leading to widespread food shortages.

As a result, two billion people could die from famine within just two years.

“It is clear that preventing nuclear war remains one of humanity’s most urgent responsibilities,” Kriley concludes.

And there’s also biological weapons

Alongside nuclear weapons, engineered biological weapons are causing growing concern.

Since 1973, when scientists created the first genetically modified bacteria, biotechnology has advanced at lightning speed — especially aided by artificial intelligence.

It is now possible to create viruses or bacteria engineered for maximum lethality, which puts them within the reach of terrorist groups or rogue states.

Otto Barten, founder of the Observatory for Existential Risks, warns: “While natural pandemics remain a very serious risk, it is very unlikely that they would cause our complete extinction. However, pandemics caused by human action could be specifically engineered to maximize effectiveness in ways that do not occur in nature. The probability that the ongoing democratization of biotechnology will eventually lead someone to try — and succeed — in creating a pandemic that causes total extinction is not negligible.”

Even an accidental laboratory leak could trigger a pandemic far worse than anything we have seen, reports Večernji list.