Nuclear winter survivors

Nuclear winter survivors

Castle Bravo nuclear test • US Department of Energy (Public Domain)

Originally published 12 March 1990

Two sto­ries in a [Jan­u­ary 1990] issue of the jour­nal Sci­ence ask us to con­sid­er the robust­ness of life.

Sto­ry No. 1 is the return of TTAPS.

TTAPS is an acronym for Tur­co, Toon, Ack­er­man, Pol­lack, and Sagan, names of the authors of the con­tro­ver­sial con­cept of nuclear winter.

TTAPS first appeared on the scene in 1983 with a paper in Sci­ence on the glob­al atmos­pher­ic con­se­quences of nuclear war. The five sci­en­tists claimed that a nuclear exchange between the super­pow­ers would have dev­as­tat­ing con­se­quences beyond the direct effects of blast and radi­a­tion. Smoke and dust inject­ed into the atmos­phere by nuclear explo­sions would plunge the plan­et into cold and dark­ness, dis­rupt­ing agri­cul­ture and the nor­mal food chain. Deaths from famine might exceed those from the blasts themselves.

Now TTAPS are back again with a reap­praisal of their orig­i­nal con­clu­sions, after five years of lab­o­ra­to­ry stud­ies, field exper­i­ments, and refine­ments of the com­put­er pro­grams that sim­u­late cli­mate change. They believe the gist of their orig­i­nal con­clu­sions about nuclear win­ter have been affirmed, and they indi­cate sev­er­al new envi­ron­men­tal dis­rup­tions that might result from nuclear war.

Global disaster

The nuclear arse­nals of the Unit­ed States and Sovi­et Union now hold about 25,000 strate­gic war­heads car­ry­ing rough­ly 10,000 mega­tons of explo­sive ener­gy. An aver­age air­burst is capa­ble of ignit­ing more than 100 square miles of area. In some nuclear war sce­nar­ios, half of the total urban­ized area of the Unit­ed States would go up in smoke, along with vast tracts of farm­land and nat­ur­al veg­e­ta­tion. Gas­es from burn­ing plas­tic would be tox­ic. With­in a week this smoke would be car­ried through­out the North­ern Hemi­sphere. Sev­er­al weeks lat­er even Aus­tralia would be affected.

The new stud­ies sum­ma­rized by TTAPS indi­cate that smoke from a nuclear exchange would be thick­er and stay in the atmos­phere longer than pre­vi­ous­ly esti­mat­ed, but expect­ed tem­per­a­ture drops are some­what less than the ear­li­er pre­dic­tions. TTAPS now say that tem­per­a­tures would fall 10 to 20 degrees Centi­grade (18 to 36 degrees Fahren­heit) in north­ern mid-lat­i­tudes, with sub-freez­ing sum­mer tem­per­a­tures in some localities.

TTAPS also point to a dan­ger­ous reduc­tion of the ozone lay­er that might fol­low a nuclear exchange. Twen­ty days after a full-scale attack, the ozone lay­er in the North­ern Hemi­sphere could be reduced by half. When the smoke final­ly cleared, sur­viv­ing organ­isms would be exposed to dou­ble the doze of harm­ful ultra­vi­o­let solar radiation.

It is not incon­ceiv­able that the com­bined effects of blast, fire, radi­a­tion, smoke tox­i­c­i­ty, famine, and ozone deple­tion in an all-out nuclear war might cause the extinc­tion of some sus­cep­ti­ble species of ani­mals and plants. The most pes­simistic pun­dits have imag­ined the extinc­tion of the human species.

Which brings us to report No. 2 and the archae­bac­te­ria.

Writ­ing in the Jan­u­ary 12, 1990 issue of Sci­ence, reporter Robert Pool describes a kind of unusu­al bac­te­ria that thrives in con­di­tions that would be fatal to all oth­er organ­isms. If we are fool­ish enough to det­o­nate 25,000 nuclear war­heads, these resilient crea­tures would no doubt sur­vive unscathed to wel­come the post-apoc­a­lypse world.

Hardy microorganisms

Carl Woese of the Uni­ver­si­ty of Illi­nois rec­og­nized the unique­ness of this col­lec­tion of organ­isms in 1977. Because they flour­ish in the harsh con­di­tions that might have exist­ed on the ear­ly Earth he named them archae­bac­te­ria, or “prim­i­tive bac­te­ria.” It now turns out that they may not be so prim­i­tive after all, but every day brings new infor­ma­tion about their remark­able abil­i­ty to adapt.

One favorite haunt of archae­bac­te­ria is sul­fur-rich hot springs, such as those at Yel­low­stone, and bub­bling vol­canic vents on the sea floor. Some archae­bac­te­ria are com­fort­able at tem­per­a­tures well above the boil­ing point of water.

Ordi­nar­i­ly, pro­teins and DNA are bro­ken apart at tem­per­a­tures above 60 or 70 degrees Centi­grade. Cer­tain archae­bac­te­ria can go dou­ble that and sur­vive, and chemists are still try­ing to fig­ure out how they do it.

Oth­er archae­bac­te­ria live in water 10 times salti­er than the oceans. Very salty water is usu­al­ly fatal to organ­isms because it draws water out of cells. Some archae­bac­te­ria live hap­pi­ly in evap­o­ra­tion ponds where salt is har­vest­ed from sea water. There are archae­bac­te­ria that make them­selves at home in lakes and ponds as alka­line as house­hold ammo­nia and oth­ers that pre­fer envi­ron­ments more acidic than gas­tric acid.

Still oth­er are barophiles, “lovers of pres­sure.” They grow in the deep­est trench­es of the sea, at pres­sures that would crush a nor­mal submarine.

Archae­bac­te­ria demon­strate the elas­tic­i­ty of the envi­ron­men­tal enve­lope for life. From the cold, crush­ing depths of the oceans to the bub­bling sul­fur pools of Yel­low­stone to the bak­ing salt pans of the trop­ics, life can and does survive.

There is in all of this a somber but (mild­ly) reas­sur­ing les­son. No imag­in­able apoc­a­lypse is like­ly to sound the death knell for all life on Earth. We may have cre­at­ed the con­di­tions for our own extinc­tion — and cer­tain­ly for the extinc­tion of civ­i­liza­tion as we know it — but for cer­tain of the plan­et’s inhab­i­tants, a nuclear war may be no more severe than a pass­ing cloud on a sum­mer’s day.


Since this essay was first writ­ten, archae­bac­te­ria, now known as archaea, have been reclas­si­fied into their own tax­o­nom­ic Domain sep­a­rate from all oth­er microor­gan­isms due to their unique char­ac­ter­is­tics. ‑Ed.

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