If you live in a large city in the U.S., Russia, or any other nation possessing nuclear weapons, there is at least one nuclear warhead aimed at you. It patiently waits day and night for a computer to give it your address and send it on a 10 to 30 minute flight to incinerate you and your family. There are many thousands of strategic nuclear warheads kept constantly ready to turn the cities of the world into hurricanes of fire.

Click here for a larger version Image by Steven Starr and Taylor Starr

This is a brief description of the effects which a single average sized strategic nuclear weapon would have if detonated above the Pentagon in Washington, D.C. (dozens of such weapons are probably targeted upon D.C. by Russia). The warhead has an explosive power of 300 kilotons (kT), equaling 600 million pounds of dynamite and would be detonated at an altitude of 1500 feet above its target.

A 300 kT warhead would within a millionth of a second release 300 trillion calories of energy primarily in the form of intense light. The surrounding air would be superheated and create a rapidly expanding fireball. Almost all the air within and around the fireball would be compressed into a steeply fronted luminous blast wave of enormous extent and power.

The fireball would extend more than a mile in diameter and at its center produce temperatures of over 200 million degrees Fahrenheit, about four to five times the temperature found at the center of the sun. This unearthly release of heat and energy would create an environment of unimaginable lethality, igniting extensive fires for many tens of square miles and producing a blast wave which would crush and tear apart any structures in its path. The blast wave would also increase the incidence and rate of fire spread by exposing ignitable surfaces, releasing flammable materials and dispersing burning objects.

At Pentagon City, a shopping and office complex 0.7 miles from ground zero at the Pentagon, light from the fireball would melt asphalt in the streets, burn paint off walls, and melt metal surfaces within a half second of detonation. The interior of vehicles in line of sight of the fireball would explode into flames.

About one second later, the blast wave and 750 miles per hour (mph) winds would arrive and toss burning and disintegrating vehicles into the air like leaves in a wind. The blast wave could cave in buildings and would turn windows and furniture into missiles and shrapnel. The interiors of buildings that remained standing would, within minutes, be burning pyres of splintered walls, doors and other combustibles. Seconds after the passage of the blast wave, suction effects created in part by the rising fireball would reverse the winds, drawing them toward the detonation point at perhaps 50 – 70 mph.

All the areas within 1.3 miles of the Pentagon (almost all of the Arlington National Cemetery, most of the Virginia Highlands and Addison Heights neighborhoods, and parts of Washington D.C. reaching to the Lincoln and Jefferson memorials) would experience more than 15 times the thermal energy found at the edge of the mass fire which destroyed Hiroshima. The fireball here would, for a moment, shine 5,000 times brighter than a desert sun at noon.

Grass, vegetation, and leaves on tress would explode into flames, and the surface of the ground would explode into superheated dust. Flames and black smoke would spew out from all combustible materials illuminated by the fireball. The marble on the Lincoln and Jefferson memorials would crack, pop, and possibly evaporate. The light would melt the surface of the bronze statue of Jefferson. Birds in flight would drop from the sky in flames. People exposed to the light would be instantly cremated.

Four seconds later the blast wave would arrive and collapse the Jefferson and Lincoln memorials. This would be followed by winds of 300-400 mph which combining with the blast wave would completely destroy wood-frame and residential brick buildings. Aluminum surfaces on the aircraft at the Reagan National Airport would melt and warp. Interior sections of the aircraft exposed to the fireball would burst into flame. Tires on the aircraft and any nearby vehicles would also catch fire.

Within 3 miles of ground zero the clothing worn by people in direct line of sight of the fireball would burst into flames or melt, and areas of skin not covered by clothing would be scorched, charring flesh and causing third-degree burns. For many miles in all directions, any creature unfortunate enough to look into the fireball at the time of detonation would either be blinded or suffer permanent retinal damage.

Only a few mass fires have occurred in human history; those created by British and American conventional incendiary weapons and the U.S. atomic bombs in World War II. The unique features of the mass fire – the simultaneous combustion of many fires over a large area, which causes a great volume of air to heat, rise, and suck in large amounts of fresh air at hurricane speeds from the periphery – fundamentally distinguish it from other fires in history (otherwise know as line fires, which can burn and spread for days, but were not simultaneously set over large areas).

Fire environments created by mass fires are fundamentally more violent and destructive than fires of smaller scale, and they are far less affected by external weather conditions. Because their dynamics are dominated by the intense hydrodynamic flows generated by the vast releases of energy from combustion in an area of enormous size and the resulting rise of air over the fires zone, these fires are not substantially altered by seasonal and daily weather conditions.

The 300kT detonation would create a mass fire with a radius of 3.5 miles in all but the most extreme weather conditions. Under a majority of weather conditions, there would be a mass fire ignited to a distance of just over 4.5 miles from the detonation.

This gigantic fire would quickly increase in intensity and in minutes generate ground winds of hurricane force with average air temperatures well above the boiling point of water (212 degrees F). The fire would then burn everywhere at this intensity for three to six hours, producing a lethal environment over a total area of approximately 40 to 65 square miles – an area about 10 to 15 times larger than that incinerated by the 15 kT atomic bomb which destroyed Hiroshima.

Even after the fires burned out, street pavement would be so hot that even tracked vehicles could not pass over it for days, and buried and unburned materials from collapsed buildings could burst into flames if exposed to air even weeks after the attack. Those who sought to flee through the streets would be burned alive by hurricane-force winds laden with flames and firebrands. Even those who sought shelter in the deepest subbasements of massive buildings would likely die from heat prostration, suffocation, or lack of water. There would be no escape. The fire would eliminate all life in the fire zone.

The smoke and mushroom cloud, seething with radioactivity, would rise up to blot out the sun. Deadly fallout would contaminate hundreds of square miles downwind with radioactive poisons from the blast, dooming hundreds of thousands of humans and animals to a painful, vicious death from radiation sickness. Much of the land contaminated by the fallout would remain uninhabitable for years. Scattered deaths and higher mortality rates would continue for centuries from cancer, leukemia, and genetic damage to succeeding generations.

Imagine this same event happening, in less than an hour, with not one, but with thousands of strategic nuclear weapons detonating in the cities of the U.S., Russia, China, Europe, India, and Pakistan. The details of such a holocaust are already inscribed in the guidance mechanisms of the missiles waiting to deliver the warheads. Now you understand what the global nuclear arsenals, continually kept at launch on warning status, are capable of doing.

What are you going to do about it?

Most of the information in this article has been taken, with the permission of the author, from the first chapter of the book by Lynn Eden, Whole World on Fire (Cornell University Press, 2004). An adaptation of this first chapter also appeared as “City on Fire,” Bulletin of the Atomic Scientists (January/February 2004). Anyone interested in learning more about this subject should read these works.