While much of the world worries about the creeping consequences of global warming, a group of scientists from the National Center for Atmospheric Research, the Federation of American Scientists and a collection of universities have been studying the danger of rapid, global cooling.
Their examination focuses on the risks of nuclear war between Pakistan and India, two countries at war or on the verge of war for decades. They last battled in 1999 and fought a major conflict in 1971, the end result of which was East Pakistan breaking away to become Bangladesh.
Afterward, Pakistan vowed it would never lose another war with India.
“Unlike neighboring India and China, Pakistan does not have a ‘no first use’ doctrine,” Kyle Mizokami writes at The National Interest, “and reserves the right to use nuclear weapons, particularly low-yield tactical nuclear weapons, to offset India’s advantage in conventional forces.
“The nuclear standoff is exacerbated by the traditional animosity between the two countries, the several wars the two countries have fought, and events such as the 2008 terrorist attack on Mumbai, which were directed by Pakistan.”
Aware of the risks, scientists have now calculated what might happen if a full-scale, nuclear war broke out between the two countries. They predict it would spawn a planet-spanning “nuclear winter.”
The fear of nuclear winter has disappeared from the thoughts of most Americans in the almost 40 years since scientists used the threat to push for agreement on international arms control.
“This shocking possibility (of nuclear winter), and the intense debate surrounding it, brought the insanity of the continuing nuclear arms race to the front burner,” researchers Alan Robock and Owen Brian Toon later observed in the Bulletin of the Atomic Scientists. “The scientific message, from research done jointly by American and Soviet scientists, was based on primitive computer models of the climate system, yet the physics were clear: If you block out enough sunlight, it gets cold, dark, and dry at the surface, and the destruction of the ozone layer allows deadly ultraviolet radiation to penetrate the atmosphere. The scientists’ models motivated U.S. President Ronald Reagan and Soviet General Secretary Mikhail Gorbachev to reach agreement on a nuclear arms reduction treaty.”
Nuclear winter has remained largely out of sight, out of mind since then despite the collapse and disintegration of the Union of Soviet Socialists Republics and the rise of new tensions between its successor, the Russian Federation led by Vladimir Putin, and the U.S.
Relations between the two countries are today strained, but no one harbors major concerns about the sort of nuclear conflict feared at the height of the so-called “Cold War” in the 1960s and ’70s.
Still, some scientists see the threat of nuclear war very much alive in the Indian subcontinent.
“If India uses 100 strategic weapons to attack urban centers and Pakistan uses 150,” the researchers wrote, “fatalities could reach 50 to 125 million people, and nuclear-ignited fires could release 16 to 36 teragrams of black carbon in smoke, depending on yield. The smoke will rise into the upper troposphere, be self-lofted into the stratosphere, and spread globally within weeks. Surface sunlight will decline by 20 to 35 percent, cooling the global surface by 2° to 5° Celcius and reducing precipitation by 15 to 30 percent, with larger regional impacts. Recovery takes more than 10 years.”
Two to five degrees Celcius equals three-point-six to nine degrees Fahrenheit. The global warming to date is estimated at 1.5 degrees and projected to rise to up to 7.2 degrees by 2050, according to the National Aeronautics and Space Administration (NASA), although the increase will not be uniform. The Arctic is expected to warm more than the rest of the globe.
A Pakistan-India ignited nuclear winter could, however, zero out all of that in a flash, according to the research.
Residents of Alaska’s largest city thi summer got a tiny taste of what a nuclear winter might be like as forest fires raged to the north and south. Dense smoke sometimes blocked the heat of the warm, midnight sun and temperatures in Anchorage dropped noticeably at those times.
Smoke from forest fires doesn’t, however, begin to compare to what happens after a nuclear explosion in an urban area.
“In forest fires, only a small fraction of the fuel is consumed,” the scientists wrote. “The values…are 10 to 25 percent of the fuel load expected in boreal forests. In addition, the accessible fuel loading is substantially lower in forests than in urban areas. In total, the fuel burned in the urban areas in our 15-kiloton scenario is about 60 times greater than estimated for typical forest fires.”
The result of all the smoke is the opposite of what happens with the build-up of carbon dioxide (CO2) in the atmosphere. A colorless gas, CO2 allows solar radiation to pass through.
The solar radiation hits the earth and warms it. But when the earth tries to dump heat back into space in the form of infrared radiation, CO2 and other so-called “greenhouse gases” absorb some of the energy and redirect some back toward the earth.
The result is a warming planet.
Smoke in the atmosphere shifts the equation by blocking the sun’s rays from hitting the earth’s surface. That has a significant cooling effect.
“With a loss of solar radiation at the surface, the surface cools and evaporation, convection, and precipitation are reduced,” the study says. “…The global average surface temperature drops between 1.25° and 6.5°C over several years for our scenario. These perturbations reach their peak about three years after the conflict and are near the peak value for about four years. It takes more than a decade for temperatures and precipitation to return to normal. The Last Glacial Maximum, 20,000 years ago, had a global temperature decline of about 3° to 8°C relative to preindustrial temperatures, but these temperature decreases persisted for thousands of years.”
Calculating the odds
How likely is a nuclear war between Pakistan and India?
No one can say.
The new study notes Britain, France, China and Israel – along with the U.S. and Russia – now possess sizable stockpiles of nuclear weapons, but argues that “India and Pakistan are of special concern because of a long history of military clashes including serious recent ones, lack of progress in resolving territorial issues, densely populated urban areas, and ongoing rapid expansion of their respective nuclear arsenals. Here, we examine the possible repercussions of a nuclear war between India and Pakistan circa 2025 in which cities are one class of target, either by direct or collateral targeting.”
The two countries are estimated to have 140 to 150 warheads each at this time, but appear to be growing their stockpiles toward “200 to 250 warheads in each country by 2025,” the study says.
Israel, another country in a volatile part of the world, is believed to have but 80 nuclear weapons, while Frnce has 300; China, 270; Britian, 215; and North Korea, up to 60. The other more than 12,000 on the planet are split between the U.S. and Russia.
“Although India does not need so many weapons to attack Pakistan, India is also concerned about China,” the study says. “China has about 360 cities with more than 100,000 inhabitants, so it is possible that India is sizing its nuclear forces in case of a nuclear conflict with China.”
China is an ally of Pakistan, which fears India’s larger and better-equipped military.
“India has conventional military superiority,” the study notes. “India is also geographically much larger than Pakistan. One possible route to nuclear war involves a conventional conflict between India and Pakistan. If Pakistan perceived that India were about to successfully invade them, that would put pressure on Pakistan to launch its nuclear weapons before they were overrun by the superior conventional Indian forces.
“Another possibility for starting a nuclear conflict is that India or Pakistan could lose control of its command and control structures due to an attack on them by the other side or possibly an attack by terrorists from within India or Pakistan or from another country. In such a scenario, it is not clear who might be in control of the nuclear forces and what steps they might take. A third possibility for starting a nuclear conflict is that India or Pakistan might mistake an attack by conventional forces, or even military exercises, for an attack by nuclear forces.”
The study presumes that once one country goes nuclear, for whatever reason, the other country is likely to respond in kind. Were that to happen, the study’s authors also warn that the situation could get much worse than their forecast.
“We assume that India will keep 100 nuclear weapons in its arsenal to deter China from entering the war,” they write. “Chinese involvement would greatly amplify the destruction discussed below. As China expands its presence in Pakistan as part of the China-Pakistan Economic Corridor, which is an element of China’s broader ‘Belt and Road Initiative,’ the odds of a Pakistani-Indian war spreading to China would appear to be increasing.”
Any nuclear war is expected to produce global consequences. A war limited to Pakistan and India would kill millions in those two countries, but the reign of death would go global.
“Because of the near-term regional effects of nuclear blast, thermal radiation, and prompt nuclear radiation, we find that perhaps for the first time in human history, the fatalities in a regional war could double the yearly natural global death rate,” the study says. “Moreover, the environmental stresses related to climate changes caused by smoke produced from burning cities could lead to widespread starvation and ecosystem disruption far outside of the war zone itself.”
Net primary production (NPP) north of 60 degrees latitude – about the latitude of Cordova, Alaska – would fall to zero over the first three years after the war, the study says, and “major crop-growing regions of North America and Eurasia experience declines of NPP averaging 25 to 50 percent over this time.
“Very large reductions in NPP occur in India, China, Southeast Asia, and Indonesia, as well as in tropical South America and Africa. Ocean reductions in NPP are highest in the Arctic, where production is almost entirely extinguished. In addition, in many regions where major fisheries exist, production is significantly reduced, including the North Atlantic and North Pacific, where NPP decreases by 25 to 50 percent.
“Together, the reductions in temperature, primary productivity, and precipitation suggest major disruptions to human and natural systems worldwide.”
Already heavily dependent on imports for fruits, vegetables and most agricultural staples – and facing a major reduction in fish, the state’s one major agricultural crop – could expect to be extremely hard hit.