By Ira Helfand and Asha Asokan
Today, the world lives in the shadow of two grave and deeply related existential threats. There is a growing awareness of the danger posed by the climate crisis and the urgent need to reduce greenhouse gas emissions to limit the extent of global warming. There is less attention given to the threat of nuclear war, though, if anything, nuclear weapons pose an even greater and more imminent danger. Further these threats are deeply inter-connected. Climate change increases the likelihood of nuclear war and, if it comes, nuclear war will cause devastating abrupt climate disruption. It is essential that we develop an effective strategy for dealing with both of them.
There are some 13,000 nuclear warheads in the arsenals of the world’s 9 nuclear- armed states, all of which are currently spending billions of dollars to enhance their nuclear forces. Tensions between the US and Russia, the US and China, and India and Pakistan are at historic highs. As climate change progresses, all nuclear powers will face increased economic and social stress with a concomitant increased risk of conflict among them.
Nowhere is the relation between the climate crisis and the growing threat of nuclear war clearer than in South Asia, where some 700 million people in India, Pakistan, China, and Bangladesh depend on the shared waters of the Indus, Ganges and Brahmaputra river basins. All these river systems are fed by Himalayan glaciers that are disappearing as a result of climate change.
Perhaps the most dangerous flashpoint is the Indus River on which hundreds of millions of people in India and Pakistan depend. The Indus water dispute has been an ongoing issue between India and Pakistan since the separation in 1947. In 1960 both countries signed The Indus Water Treaty initiated and mediated by World Bank. The treaty defines India and Pakistan’s rights, restrictions, and obligations to use the Indus River. The treaty was considered an example of a successful mechanism for cooperation until recently. However, the increasing water stress caused by climate change, tension in the disputed territory of Jammu and Kashmir, the construction of hydroelectric power plants by India on one side and Pakistan on the other side is increasingly straining the treaty.
While Pakistan is entitled under the treaty to 60% of the Indus water, dams on the Indian side of the border control flow of the river downstream. India has already threatened to cut off water flow to Pakistan in the event of further tension between the two over Kashmir, a step that Pakistan would certainly consider an act of war. Given the great disparity between their conventional forces—India has a much larger military—it is almost certain that a future war between them would escalate to a nuclear conflict.
India and Pakistan each have about 150 nuclear warheads, and both are building additional weapons. If they targeted a total of 250 of these warheads at urban, industrial targets, 75 to 100 million people could be killed directly by the explosions, fires and radiation. But the effects would extend far beyond South Asia. The fires started by these nuclear explosions would loft anywhere from 16 to 37 million tons of soot into the upper atmosphere depending on the size of the warheads. This, in turn, would drop global temperatures an average of 2.50C to 5.5)C. This abrupt cooling would wreak havoc with global food production particularly in North America, Russia, Northern Europe and China and would trigger a worldwide famine unprecedented in human history with billions of people at risk of starvation. Such an event would not lead to the extinction of our species, but it would end modern industrial civilization.
A war between the US and Russia or the US and China would cause even greater climate disruption.
Catastrophic climate change is a certainty if we do not take decisive action to prevent it. A nuclear war may occur at anytime and the likelihood increases as climate change progresses. We have the ability to limit climate change and to eliminate nuclear weapons. Future generations will judge us by whether we successfully address these two great threats.