Nuclear winter redux

by | Mar 23, 2010


Mushroom Cloud Blues

Ever wondered what a nuclear strike would do to the environment?

The detonation of 100 15-kiloton nuclear weapons in Indian and Pakistani megacities would create urban firestorms that would loft 5 million tons of thick, black smoke above cloud level. (This smoke would engulf the entire planet within 10 days.)

Because the smoke couldn’t be rained out, it would remain in the stratosphere for at least a decade and have profoundly disruptive effects. Specifically, the smoke layer would block sunlight, heat the upper atmosphere, and cause massive destruction of protective stratospheric ozone.

2008 study PDF calculated ozone losses (after the described conflict) of 25-45 percent above mid-latitudes and 50-70 percent above northern high latitudes persisting for five years, with substantial losses continuing for another five years. Such severe ozone depletion would allow intense levels of harmful ultraviolet light to reach Earth’s surface–even with the stratospheric smoke layer in place.

Beneath the smoke, the loss of warming sunlight would produce average surface temperatures colder than any experienced in the last 1,000 years. There would be a corresponding shortening of growing seasons by up to 30 days and significant reductions in average rainfall in many areas, with a 40-percent decrease of precipitation in the Asian monsoon region.

Basically, the Earth’s surface would become cold, dark, and dry.

Via @jduncanMACD – the UK’s tweeting Ambassador for Multilateral Arms Control and Disarmament.

Author

  • David Steven is a senior fellow at the UN Foundation and at New York University, where he founded the Global Partnership to End Violence against Children and the Pathfinders for Peaceful, Just and Inclusive Societies, a multi-stakeholder partnership to deliver the SDG targets for preventing all forms of violence, strengthening governance, and promoting justice and inclusion. He was lead author for the ministerial Task Force on Justice for All and senior external adviser for the UN-World Bank flagship study on prevention, Pathways for Peace. He is a former senior fellow at the Brookings Institution and co-author of The Risk Pivot: Great Powers, International Security, and the Energy Revolution (Brookings Institution Press, 2014). In 2001, he helped develop and launch the UK’s network of climate diplomats. David lives in and works from Pisa, Italy.


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