Nuclear winter in the context of Stratosphere

Paul Jozef Crutzen (Dutch pronunciation: [pʌul ˈjoːzəf ˈkrʏtsə(n)]; 3 December 1933 – 28 January 2021) was a Dutch meteorologist and atmospheric chemist. In 1995, he was awarded the Nobel Prize in Chemistry alongside Mario Molina and Frank Sherwood Rowland for their work on atmospheric chemistry and specifically for his efforts in studying the formation and decomposition of atmospheric ozone. In addition to studying the ozone layer and climate change, he popularized the term Anthropocene to describe a proposed new epoch in the Quaternary period when human actions have a drastic effect on the Earth. He was also amongst the first few scientists to introduce the idea of a nuclear winter to describe the potential climatic effects stemming from large-scale atmospheric pollution including smoke from forest fires, industrial exhausts, and other sources like oil fires.

He was a member of the Royal Swedish Academy of Sciences and an elected foreign member of the Royal Society in the United Kingdom.

A nuclear explosion is an explosion that occurs as a result of the rapid release of energy from a high-speed nuclear reaction. The driving reaction may be nuclear fission or nuclear fusion or a multi-stage cascading combination of the two, though to date all fusion-based weapons have used a fission device to initiate fusion, and a pure fusion weapon remains a hypothetical device. Nuclear explosions are used in nuclear weapons and nuclear testing.

Nuclear explosions are extremely destructive compared to conventional (chemical) explosives, because of the vastly greater energy density of nuclear fuel compared to chemical explosives. They are often associated with mushroom clouds, since any large atmospheric explosion can create such a cloud. Nuclear explosions produce high levels of ionizing radiation and radioactive debris that is harmful to humans and can cause moderate to severe skin burns, eye damage, radiation sickness, radiation-induced cancer and possible death depending on how far a person is from the blast radius. Nuclear explosions can also have detrimental effects on the climate, lasting from months to years. A small-scale nuclear war could release enough particles into the atmosphere to cause the planet to cool and cause crops, animals, and agriculture to disappear across the globe—an effect named nuclear winter.

Nuclear warfare, also known as atomic warfare, is a military conflict or prepared political strategy that deploys nuclear weaponry. Nuclear weapons are weapons of mass destruction; in contrast to conventional warfare, nuclear warfare can produce destruction in a much shorter time and can have a long-lasting radiological result. A major nuclear exchange would likely have long-term effects, primarily from the fallout released, and could also lead to secondary effects, such as "nuclear winter", nuclear famine, and societal collapse. A global thermonuclear war with Cold War-era stockpiles, or even with the current smaller stockpiles, may lead to various scenarios including human extinction.

To date, the only use of nuclear weapons in armed conflict occurred in 1945 with the American atomic bombings of Hiroshima and Nagasaki. On August 6, 1945, a uranium gun-type device (code name "Little Boy") was detonated over the Japanese city of Hiroshima. Three days later, on August 9, a plutonium implosion-type device (code name "Fat Man") was detonated over the Japanese city of Nagasaki. Together, these two bombings resulted in the deaths of approximately 200,000 people and contributed to the surrender of Japan, which occurred before any further nuclear weapons could be deployed.

The Atomic Age, also known as the Atomic Era, is the period of history following the detonation of the first nuclear weapon, The Gadget at the Trinity test in New Mexico on 16 July 1945 during World War II. Although nuclear chain reactions had been hypothesized in 1933 and the first artificial self-sustaining nuclear chain reaction (Chicago Pile-1) had taken place in December 1942, the Trinity test and the ensuing bombings of Hiroshima and Nagasaki that ended World War II represented the first large-scale use of nuclear technology and ushered in profound changes in sociopolitical thinking and the course of technological development.

While atomic power was promoted for a time as the epitome of progress and modernity, entering into the nuclear power era also entailed frightful implications of nuclear warfare, the Cold War, mutual assured destruction, nuclear proliferation, the risk of nuclear disaster (potentially as extreme as anthropogenic global nuclear winter), as well as beneficial civilian applications in nuclear medicine. It is no easy matter to fully segregate peaceful uses of nuclear technology from military or terrorist uses (such as the fabrication of dirty bombs from radioactive waste), which complicated the development of a global nuclear-power export industry right from the outset.

Nuclear warfare, also known as atomic warfare, is a military conflict or prepared political strategy that deploys nuclear weaponry. Nuclear weapons are weapons of mass destruction; in contrast to conventional warfare, nuclear warfare can produce destruction in a much shorter time and can have a long-lasting radiological result. A nuclear exchange would likely have long-term effects, primarily from the fallout released, and could also lead to secondary effects, such as "nuclear winter", nuclear famine, and societal collapse. A global thermonuclear war with Cold War-era stockpiles, or even with the current smaller stockpiles, may lead to various scenarios including human extinction.

As of 2025, the only use of nuclear weapons in armed conflict was the United States atomic bombings of Hiroshima and Nagasaki, on August 6 and 9, 1945, in the final days of World War II. The two bombings resulted in the deaths of between 150,000 and 246,000 people. A debate continues over ethical, legal, and military aspects of the bombings, including their role in the surrender of Japan.

A nuclear holocaust, also known as a nuclear apocalypse, nuclear annihilation, nuclear armageddon, or atomic holocaust, is a theoretical scenario where the mass detonation of nuclear weapons causes widespread destruction and radioactive fallout, with global consequences. Such a scenario envisages large parts of the Earth becoming uninhabitable due to the effects of nuclear warfare, potentially causing the collapse of civilization, the extinction of humanity, or the termination of most biological life on Earth.

Besides the immediate destruction of cities by nuclear blasts, the potential aftermath of a nuclear war could involve firestorms, a nuclear winter, widespread radiation sickness from fallout, and/or the temporary (if not permanent) loss of much modern technology due to electromagnetic pulses. Some scientists, such as Alan Robock, have speculated that a thermonuclear war could result in the end of modern civilization on Earth, in part due to a long-lasting nuclear winter. In one model, the average temperature of Earth following a full thermonuclear war falls for several years by 7 to 8 °C (13 to 15 degrees Fahrenheit) on average.

Nuclear famine is a hypothesized famine considered a potential threat following global or regional nuclear exchange. It is thought that even subtle cooling effects resulting from a regional nuclear exchange could have a substantial impact on agriculture production, triggering a food crisis amongst the world's survivors.

While belief in the "nuclear winter" hypothesis is both popular and heavily debated, the issue of potential food supply disruption from blast and fallout effects following a nuclear war is less controversial. Several books have been written on the food supply issue, including Fallout Protection, Nuclear War Survival Skills, Would the Insects Inherit the Earth and Other Subjects of Concern to Those Who Worry About Nuclear War, and most recently the extreme nuclear winter and comet impact countermeasuring Feeding Everyone No Matter What.

Pax Atomica (Latin for “Atomic Peace”) is one of the terms that has sometimes been used to describe the period of severe tensions without a major military conflict between the United States and the Soviet Union during the Cold War. The term is also at times used to describe the entire post World War II/ post-atomic-bomb era. In the phrase's narrower application, applying only to the Cold War era, the phrase refers to the argument that the stability between the two superpowers was caused by each side's large nuclear arsenals which led to a state of Mutually Assured Destruction (MAD) and deterrence. That is, if one of the superpowers would have launched a nuclear attack, the other would have responded in the same way, resulting in the destruction of both countries, and potentially global mass starvation due to nuclear winter. John Lewis Gaddis has described the period as the Long Peace.

In the phrase's broader application, applying to the entire post World War II era, the phrase refers to the argument that the possession of nuclear arms by several of the world's larger powers has tended to act to prevent the outbreak of full-scale warfare between any of these several powers, also due to the probability of MAD.