What Would Happen If All the World’s Nuclear Weapons Were Launched at Once? Experts Warn of Near-Total Human Collapse

Global Affairs | Special Report

If every nuclear weapon in the world were launched at the same time, the consequences would go far beyond a traditional war. Scientists and security experts agree that such an event would trigger a chain reaction capable of collapsing modern human civilization and pushing humanity toward the brink of extinction.

At present, the world possesses more than twelve thousand nuclear warheads, many of them far more powerful than the bombs dropped on Hiroshima and Nagasaki. A simultaneous launch scenario would involve thousands of explosions striking major cities, military installations, and strategic infrastructure across multiple continents within minutes.

The first hour of a global nuclear war would be marked by unimaginable destruction. Entire metropolitan areas would be erased almost instantly as extreme heat, shockwaves, and firestorms consume everything in their path. Temperatures at explosion sites would reach millions of degrees, vaporizing buildings and killing hundreds of millions of people before emergency responses could even begin. Experts estimate that several hundred million deaths could occur within the first hour alone.

In the days that follow, radioactive fallout would spread far beyond the targeted areas. Massive clouds of nuclear debris would enter the atmosphere and travel across borders, contaminating air, water, and soil on a global scale. Countries not directly attacked would still suffer severe radiation exposure. At the same time, global infrastructure would collapse as power grids fail, communication networks shut down, satellites are damaged, and governments lose the ability to coordinate any form of response.

Medical systems would be overwhelmed or destroyed entirely. Hospitals would lack electricity, clean water, and staff, while survivors exposed to radiation would face severe burns, organ failure, and long-term health complications with no access to treatment.

The most devastating impact, however, would emerge in the weeks and months after the explosions. Scientists warn that a phenomenon known as nuclear winter would begin to take hold. Smoke and soot from burning cities would rise into the upper atmosphere, blocking sunlight and causing a sharp drop in global temperatures. Studies suggest that average temperatures could fall by several degrees worldwide, while sunlight levels could decrease dramatically, disrupting rainfall patterns and shortening growing seasons.

As a result, global food production would collapse. Crops such as wheat, rice, and corn would fail across multiple regions, while livestock would die due to lack of feed and extreme climate conditions. Ocean ecosystems would also suffer as cooling waters and reduced sunlight disrupt marine food chains. Within a short period, billions of people would face starvation, even in countries far removed from the initial nuclear strikes.

Experts believe that the majority of human deaths in such a scenario would not come from the explosions themselves, but from famine, disease, and social breakdown in the years that follow. Estimates suggest that up to five or six billion people could die due to hunger and related illnesses as global supply chains disintegrate and food becomes unavailable.

No country would remain safe. Highly populated regions, including South Asia, would face extreme risks due to nuclear targeting, regional fallout, and dependence on food imports. Nations like Pakistan would be affected not only by direct strikes but also by radioactive contamination, water shortages, and the collapse of international trade.

In the long term, while the Earth’s environment would slowly begin to recover over decades, human civilization as it exists today would not. Survivors would likely live in isolated groups, without modern technology, stable governments, or global connectivity. The world would resemble a pre-industrial or even primitive state, with limited knowledge preserved from the previous era.

Experts conclude that a full-scale global nuclear war would produce no winners. Nuclear weapons, often justified as tools of deterrence, represent the greatest existential threat to humanity. A scenario in which all nuclear weapons are launched at once would mark the end of modern civilization and possibly the beginning of humanity’s final chapter.