Nuclear war simulation forgets the Medieval Climate Optimum
Story submitted by P. Wayne Townsend
Yesterday’s Daily Mail carried an article about a simulation of the climate consequences of nuclear war. The paper Multidecadal global cooling and unprecedented ozone loss following a regional nuclear conflict is not paywalled gives the usual horror stories (nuclear winter, crop failures, etc.).
What caught my eye was this idea intellectual relic found in both the Daily Mail article and here quoted from the abstract of itself.
Our calculations show that global ozone losses of 20%–50% over populated areas, levels unprecedented in human history, would accompany the coldest average surface temperatures in the last 1000 years
1000 years would be 1014, during the Medieval Climate optimum. Digging deeper we find that, indeed, Michael Mann’s discredited hockey stick is the zombie reference for this claim.
The severe increases in UV radiation following a regional nuclear war would occur in conjunction with the coldest average surface temperatures in the last 1000 years [Mann et al., 1999].
Of course, this is a model of climate after a nuclear wars so, perhaps these may be disciples or wannabes of the distinguished Mr. Mann. With a reference to Mann this long after refutation, will we ever be able to get rid of this zombie science, or are we doomed to living in the land of the walking dead papers?
The paper is available here: http://onlinelibrary.wiley.com/doi/10.1002/2013EF000205/abstract
We present the first study of the global impacts of a regional nuclear war with an Earth system model including atmospheric chemistry, ocean dynamics, and interactive sea ice and land components. A limited, regional nuclear war between India and Pakistan in which each side detonates 50 15 kt weapons could produce about 5 Tg of black carbon (BC). This would self-loft to the stratosphere, where it would spread globally, producing a sudden drop in surface temperatures and intense heating of the stratosphere. Using the Community Earth System Model with the Whole Atmosphere Community Climate Model, we calculate an e-folding time of 8.7 years for stratospheric BC compared to 4–6.5 years for previous studies. Our calculations show that global ozone losses of 20%–50% over populated areas, levels unprecedented in human history, would accompany the coldest average surface temperatures in the last 1000 years. We calculate summer enhancements in UV indices of 30%–80% over midlatitudes, suggesting widespread damage to human health, agriculture, and terrestrial and aquatic ecosystems. Killing frosts would reduce growing seasons by 10–40 days per year for 5 years. Surface temperatures would be reduced for more than 25 years due to thermal inertia and albedo effects in the ocean and expanded sea ice. The combined cooling and enhanced UV would put significant pressures on global food supplies and could trigger a global nuclear famine. Knowledge of the impacts of 100 small nuclear weapons should motivate the elimination of more than 17,000 nuclear weapons that exist today.