Thursday, February 22, 2007

"Little" wars cause huge problems

Climatic Consequences of Regional Nuclear Conflicts
by A. Robock, et al
Published in Atmospheric Chemistry & Physics Discussion 11/22/06

Last fall, a decidedly unpublicized climate conference revealed what anyone with common sense probably already suspected: even little nuclear wars suck.
Read it here
Not only would a regional war using "just" 100 Hiroshima-sized warheads (about 15 kt each, or a total of 0.03% of the globe's nuclear killing capacity) potentially kill the same number of people as died globally in World War II, but it would likely cause temperature and precipitation changes that would rival those that made the Little Ice Age (c. 1450) such a fun time to be alive, with the Black Death, famines, and related problems.
The report, by six scientists including Turco and Toon of TTAPS fame, argues that such a war would cause the average amount of shortwave radiation reaching the earth's surface globally to fall by nearly 10 times the amount it would rise given a doubling of atmospheric CO2. But while the latter doubling has been projected to occur over decades, the post-war decrease would happen within the first year, and conditions would only gradually improve over the next 10 years or so. During that time, the world would likely see a 10% average decline in precipitation and a 1 deg. C average temperature decline for at least five of those years.
While that may not sound bad to the average person, the report's charts and maps are significantly more chilling right after a war: Some parts of the world could see temp. drops of as much as 7 deg. C, with large swaths of western and central Canada, most of Europe, parts of Siberia,most of Australia and the African Sahel hardest hit. At the same time, screwed up atmospheric circulation could cause huge precipitation changes, cutting the rainfall over much of N. America by 20-40% and the Amazon by around 70%, while increasing rainfall by 70-100% over the Sahel and Sahara.
Obviously, losing 70% of the Amazon's rain is likely to have a significantly larger effect than doubling the Sahara's.
Add those things together, and the Robock team is predicting large changes in the growing season for most of the world's breadbasket regions, with North America, western Eurasia and southern South America losing up to a month's growing time for several years.
In doesn't take much to realize this combination of factors bodes ill for lots of people. What the report doesn't look at, however, are other synergies: radiation and/or toxins making some areas uninhabitable (Hiroshima was reinhabited quickly because its bomb was an airburst with little fallout, but wars using multiple bombs detonating in a fairly small part of the globe -- say, India & Pakistan, or Israel & Iran -- aren't likely to be so clean.); numbers of traumatized refugees and injuries that will easily overwhelm the world's medical and humanitarian system; long-term genetic concerns, for those directly affected and globally because of the increase in average radiation levels; economic chaos possibly leading to further wars that might involve the major powers, etc. These may seem exaggerated -- after all, the study looks a war that doesn't directly touch any of the world's major industrial nations -- but the last time we saw such a death toll and economic impact, most of the world had several years to prepare for and absorb it. This one could happen literally overnight.
Our government is making a big deal of Iran's supposed quest for the Bomb, and that should indeed be a global concern. But we need to put as much pressure on India, Pakistan and Israel to come clean about their programs and, far more importantly, resume GLOBAL negotiations to get rid of nuclear weapons forever...

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