Did the Cold War era make the world colder too?

[jethro]

Much of the assumptions regarding the impact of Co2 on the climate is based upon the recent rise in global temps. It is widely accepted that temps in the 20's+ 30's were at least as high or higher than today and the observed increase in todays temps is measured against a later, cooler period. I, increasingly believe the later, cooler period was in fact an artificial cooling caused by the huge amounts of Carbon 14 released into the atmosphere at the height of the Nuclear Testing era; C14 is known to be associated with cooling. The unusual winters of 1947+1963 could be as a direct result of C14 cooling the atmosphere, as could the 1970's theory of the impending Ice Age. If the post-nuclear temps cooling is disregarded and today's temps compared with those from the 20+30's, how much of an increase is left? Enough to collaborate the AGW, Co2 theory?

http://www.osti.gov/energycitations/produc...osti_id=6679759

http://www.osti.gov/energycitations/produc...osti_id=4188044

http://cdiac.ornl.gov/epubs/ndp/ndp057/ndp057.htm

http://science.howstuffworks.com/carbon-142.htm

http://www.jaysnet.com/666nuke.html

http://www.science.uva.nl/fnwiresearch/obj...-AF82BEF123F39D

Any thoughts anyone?

[parmenides3]

Hi, jethro. First, the first two and the last of your links don't seem to be working (!).

I don't think that temps. in the 1920s-30s were as hight as current temps; temps did rise between 1900-1940, at a rate similar to today. I think they peaked a bit below what we have had for the past 10 tears or so.

The cooling period runs from the 1940s-1970s; there is an approximate correlation between these dates and the dates of atmospheric nuclear testing.

I am not sure about ; 'C14 is known to be associated with cooling'. Can you explain? Isn't all atmospheric carbon linked with warming?

I would have thought that the more obvious cooling mechanism from nuclear blasts would be large amounts of atmospheric dust and aerosols.

The 1970's 'theory of an ice age' was an entirely media-stimulated piece of nonsense which came from one speculative paper in Science. It was never a widely-held scientific theory.

There is very little material on the atmospheric effects of the Nuclear testing period, or on the long-term effects on the global CO2 balance. I think there is something to the idea that the nuclear tests had at least some impact on the atmosphere, but what effect - cooling or warming?

This is an interesting area to research and worth some effort; sorry I have no easy answers. Perhaps you might like to put the question to the scientists on RealClimate, or a similar site?

good luck,

:)P

[jethro]

Hi, jethro. First, the first two and the last of your links don't seem to be working (!).

I don't think that temps. in the 1920s-30s were as hight as current temps; temps did rise between 1900-1940, at a rate similar to today. I think they peaked a bit below what we have had for the past 10 tears or so.

The cooling period runs from the 1940s-1970s; there is an approximate correlation between these dates and the dates of atmospheric nuclear testing.

I am not sure about ; 'C14 is known to be associated with cooling'. Can you explain? Isn't all atmospheric carbon linked with warming?

I would have thought that the more obvious cooling mechanism from nuclear blasts would be large amounts of atmospheric dust and aerosols.

The 1970's 'theory of an ice age' was an entirely media-stimulated piece of nonsense which came from one speculative paper in Science. It was never a widely-held scientific theory.

There is very little material on the atmospheric effects of the Nuclear testing period, or on the long-term effects on the global CO2 balance. I think there is something to the idea that the nuclear tests had at least some impact on the atmosphere, but what effect - cooling or warming?

This is an interesting area to research and worth some effort; sorry I have no easy answers. Perhaps you might like to put the question to the scientists on RealClimate, or a similar site?

good luck,

:)P

Hi P3,

I'm sorry about the links not working, I'll try again. Carbon 14 doesn't work as a warming agent, that was my initial assumption too, carbon is carbon, was my thinking. High levels of Carbon 14 are shown to exist at the same time as Glaciation, borne out by various Ice Core data. The reasons why high levels coincide with cooler temperatures and glaciation as far as I have managed to find so far, is unclear, the research seems to point to increased cloud levels. If the (assumed for arguments sake, man-made) cooler period of 1940's-1970's is removed from the CET and today's temperature is compared to the preceeding period of say 1900-1940; how large is the recent warming in comparison?

Hope these work this time.

http://www.osti.gov/energycitations/produc...osti_id=6679759

http://www.osti.gov/energycitations/produc...osti_id=4188044

[parmenides3]

Hi jethro. I'd presume then, that the C14-type carbon is being deposited as black-carbon/soot in the atmosphere, acting as an aerosol, enhancing cloud cover and reducing surface albedo on snow and ice, thereby promoting increased precipitation.

Prehistoric Carbon deposits of this kind would have to come from wildfires and large scale burning of biomass, probably as a result of heavy volcanic and tectonic activity, lightning strikes and droughts.

I'll just double-check the numbers for the other question.

:)P

[eddie]

Given that only one out of every trillion carbon atoms is C14 I would think that it is unlikely that C14 could have any physical effect on our climate.

[parmenides3]

Perhaps that is the case now, but the report (from 1957/60) states that, following the nuclear tests, something like 8.4% of the carbon in the atmosphere above NZ was C14. So, for a short time, in parts of the globe, atmospheric concentrations would presumably have been quite high, proportionally.

It's an area I've not put a lot of time into, but I'm not unhappy with the notion that some of the observed cooling between the 40s and 70s might have been attributable to increased aerosol deposition (and C14) from nuclear tests.

If you are curious, there are 2 new papers, in Atmospheric Chemistry & Physics, I believe, about the human and climate impacts of a limited regional nuclear conflict. They conclude that even a small megatonnage would result in substantial climate impacts, in particular if the explosions were in the tropical/sub-tropical zone. Here is one of the abstracts. You can also access the whole paper if you want to, via the link at the bottom: http://www.atmos-chem-phys.net/7/2003/2007...-2003-2007.html

:)P

Edited May 14, 2007 by parmenides3

[Hiya]

This cooling effect wrt C-14 doesn't make much sense to me, if anyone could post up a theory or two about the method behind it that would most useful.

[jethro]

Hi jethro. I'd presume then, that the C14-type carbon is being deposited as black-carbon/soot in the atmosphere, acting as an aerosol, enhancing cloud cover and reducing surface albedo on snow and ice, thereby promoting increased precipitation.

Prehistoric Carbon deposits of this kind would have to come from wildfires and large scale burning of biomass, probably as a result of heavy volcanic and tectonic activity, lightning strikes and droughts.

I'll just double-check the numbers for the other question.

:)P

No, that's not how C14 works. C14 and Beryillium 10 are unique in being created by Cosmic Ray Flux, it is believed they increase cloud formation, thus leading to lower temperatures. Cosmic Ray Flux is governed by the Solar cycle. Beryillium 10 attaches itself to aerosols in the atmosphere and is snowed out onto the Polar Ice Caps, thus leaving a clear signal of the level of Solar Flux. Since 1900, levels have been falling with the exception of a clear spike in the 1940/50's, this cannot be explained by changes in Solar output for the corresponding time scale.

I've included a link which explains this in greater detail; interestingly (but possible another side issue to here) concludes that by calculating the level of Solar Flux and it's effects since 1900, factoring in the effects of C14 and Baryllium 10, global temperatures would have increased by 0.6c.

I really am curious as to whether, if the period of nuclear testing was factored out of the CET figures, how close would today's temps be when compared to prior to that period and how sharp the incline of increase would be.

http://www.env.leeds.ac.uk/envi2150/oldnot...9/lecture9.html

[jethro]

Here's a few more links:

http://www2.slac.stanford.edu/vvc/cosmicrays/cratmos.html

http://www.dsri.dk/~hsv/Noter/solsys99.html

http://discovermagazine.com/1999/apr/breakweather

These explain natural formation of C14 and it's possibly effects. Finding data to correlate how much C14 we added artificially to the atmosphere via Nuclear testing is proving harder to come by; perhaps still classified?

[jethro]

I've found this list of how many nuclear bombs have been detonated, it makes stark reading. I'll try tomorrow to find correlation for these figures from a source less likely to be skewed to the extreme; their information may well be conclusive but I'd be happier to hear it from a more moderate source.

http://archive.greenpeace.org/comms/nukes/ctbt/read9.html

[Just Before Dawn]

The Greenpeace figures certainly concur with the non-classified security literature (up to this point - India has undertaken 1 further test since then, as has Pakistan, in the Chagai hills. Also, a high-atmospheric radiation spike picked up over the Indian ocean in 1979, here credited to India was more likely a joint Israeli/South African test).

Since the 1963 Partial test ban treaty, all nuclear tests have been underground, although some of these have resulted in 'venting' (where explosive by-products have escaped into the atmosphere. Therefore atmospheric by-products in the atmosphere should be concentrated during the period 1945-1963.

[eddie]

Perhaps that is the case now, but the report (from 1957/60) states that, following the nuclear tests, something like 8.4% of the carbon in the atmosphere above NZ was C14. So, for a short time, in parts of the globe, atmospheric concentrations would presumably have been quite high, proportionally.

While I agree that the dust and particles thrown into the atmosphere by nuclear testing could have cooled the earth, C14 almost certainly did not contribute to this.

The figure you quoted of 8.4% of the carbon over NZ being C14 is far far far too high.

All the nuclear tests in the world only created 1.75 tonnes of C14. Even if those 1.75 tonnes were released all in one go over New Zealand, C14 would make up only around 4.6 x 10^-9 % of the carbon in the atmosphere over NZ.

"Carbon-14 is also a weak beta emitter (156 KeV, no gamma), with a half-life of 5730 years (4.46 Ci/g). Atmospheric testing during the fifties and early sixties produced about 3.4 g of C-14 per kiloton (15.2 curies) for a total release of 1.75 tonnes (7.75x10^6 curies). For comparison, only about 1.2 tonnes of C-14 naturally exists, divided between the atmosphere (1 tonne) and living matter (0.2 tonne)."

[parmenides3]

jethro; it looks like you're heading down the Svensmark track again; looking for a link between galactic cosmic rays and climate. It's a bit of a tricky area at the moment, because of the controversy stirred up by the great gw swindle. The person most likely to help you here is Nir Shaviv (he has his own website), who is a champion of the GCR theory. Unfortunately,(not their fault) the cloud data on which Svenmark et al based their recent work has since been shown to be full of flawed data, and when these are systematically corrected, there is no evidence of any coreelation between solar flux and cloud propagation.

I'm quite good at finding articles and stuff, but this one has defeated me for some time now; the only interesting piece I've found deals with C14 flux over the last six millenia, was first produced in the 1970s, and shows a 2% variation range for atmospheric C14 over the 6000 year period. No mention in it at all of nuclear testing. All I can find are oblique references to the fact that measured C14 went up manyfold between the 40s and the 60s, but how much, and to what effect, is a total blank.

Look up 'history of atmospheric nuclear testing & you should find the relevant stats in many forms.

I'm giving up searching, and am now going to ask some climate scientists. I'll tell you what, fi anything, their response is.

:)P

Edit: eddie; the figure isn't mine, I got it from a NZ paper dating back to the 1960s. I can't say how reliable or accurate it is, or the timescale they are talking about.

Edited May 14, 2007 by parmenides3

[HighPressure]

I tend to think that Sulphur from coal burning had the main effect on global cooling, its interesting to see that the areas most hit by cooling were areas of high industrial output. I actually wonder if we are seeing a global catchup in temps artificially held down during the first 2/3 of 20th century?

[jethro]

I tend to think that Sulphur from coal burning had the main effect on global cooling, its interesting to see that the areas most hit by cooling were areas of high industrial output. I actually wonder if we are seeing a global catchup in temps artificially held down during the first 2/3 of 20th century?

I agree, Sulphur must have played a part too; global catch-up makes perfect sense to me. I suppose my curiosity comes from the fact that the nuclear age was fairly unique in as far as our capability to have such a vast impact, in such an instantaneous way. Coal burning and other pollutants are a gradual player, I'm wondering if it's possible to denote a line in climate/weather which indicates the nuclear age or whether it was lost in the overall picture. Everyone keeps saying how we never get winters of old anymore, in modern day terms that relates to living memory, the most obvious starting point being the winter of 1947, then '63. Both of these fell slap bang in the midst of the nuclear testing period, is there a connection? Also, from an environmental AGW viewpoint, Co2 emissions account for some of the steep rise in temps, Solar output may account for some of it too, but as far as I'm aware, no one to date has come up with a reason for all the increase. Could it be that the increase is neither as large or as steep as we believe? Could the starting point of the steep increase in recent years actually be from an artificially lowered temperature period?

[Devonian]

I agree, Sulphur must have played a part too; global catch-up makes perfect sense to me. I suppose my curiosity comes from the fact that the nuclear age was fairly unique in as far as our capability to have such a vast impact, in such an instantaneous way. Coal burning and other pollutants are a gradual player, I'm wondering if it's possible to denote a line in climate/weather which indicates the nuclear age or whether it was lost in the overall picture. Everyone keeps saying how we never get winters of old anymore, in modern day terms that relates to living memory, the most obvious starting point being the winter of 1947, then '63. Both of these fell slap bang in the midst of the nuclear testing period, is there a connection? Also, from an environmental AGW viewpoint, Co2 emissions account for some of the steep rise in temps, Solar output may account for some of it too, but as far as I'm aware, no one to date has come up with a reason for all the increase. Could it be that the increase is neither as large or as steep as we believe? Could the starting point of the steep increase in recent years actually be from an artificially lowered temperature period?

There surely hadn't been many (or big) nuclear test by 1947 (scroll down a little)? Russia didn't test fire a nuclear bomb until 1949. The H bombs came later still.

Edited May 15, 2007 by Devonian

[jethro]

There surely hadn't been many (or big) nuclear test by 1947 (scroll down a little)? Russia didn't test fire a nuclear bomb until 1949. The H bombs came later still.

The nuclear weapons age began on 16 July 1945 when the U.S. exploded the first nuclear bomb, codenamed 'Trinity' at Alamogordo, New Mexico. The Soviet Union was the next country to explode a bomb, with a test on 29 August 1949. Other countries followed: Britain's first test was on 3 October 1952; France's on 3 December 1960; China's on 16 October 1964 and; India's on 18 May 1974.

[Bobby]

I don't know about Carbon-14 but I doubt any fallout from nuke tests has had any affect on climate. Most nuclear tests were either underground explosions or "airbursts" - both produce very little fallout.

I believe the "nuclear winter" theory was that the burning cities from a nuclear war would release huge amounts of aerosols that may cool the atmosphere temporarily. No cities were destroyed in nuclear testing however and most explosions were either at sea or in deserts and other barren places, or just underground anyway.

A forest fire would likely put far more aerosols into the air than any nuclear test.

[Just Before Dawn]

I believe the "nuclear winter" theory was that the burning cities from a nuclear war would release huge amounts of aerosols that may cool the atmosphere temporarily. No cities were destroyed in nuclear testing however and most explosions were either at sea or in deserts and other barren places, or just underground anyway.

Quite right. It was Carl Sagan in an article in the Bulletin of Atomic Scientists in the 1970's that coined the phrase 'nuclear winter' and described what he meant in these terms. It's still a controversial subject - and one with which some nuclear physicists still have some problems with.

[jethro]

Quite right. It was Carl Sagan in an article in the Bulletin of Atomic Scientists in the 1970's that coined the phrase 'nuclear winter' and described what he meant in these terms. It's still a controversial subject - and one with which some nuclear physicists still have some problems with.

I think there maybe a little confusion here. Yes, the theory of "nuclear winter" is a well known and documented idea but it is based upon debris being blasted into the atmosphere, blocking out sunlight and causing cooling-pretty much the same way as a large volcanic explosion can cause cooling.

My questions and pondering focus upon purely the Carbon 14 element of a nuclear blast. C14 is naturally created in the atmosphere by the interraction of Cosmic Rays upon Nitrogen atoms, which then creates C14. There is no other known process by which C14 is created other than the natural Cosmic Ray formulation and Nuclear bombs. During the Cold War era the C14 content of the atmosphere was nearly doubled in a very short space of time. From the Vostok and other Ice Core samples it is known that larger than usual levels of C14 were apparent at the time of past Ice Ages. I am wondering if the unusually high levels created by man during the Cold War era led in anyway to the global cooling pattern recorded in the CET. Prior to this era, temperatures were on the increase but fell quite sharply during that time. The perceived sharp increase of temperatures during recent years would therefore be less steeply curved if the temperatures had been artificially lowered during 1945-1970's. Could what we are experiencing now actually be a more gradual, steady rising of temperatures that is a continuation of a warming period which began much earlier. Would this gradual increase make the driver more likely to natural in origin? If so, then where does it leave the general consensus on AGW and the accreditation of more Co2=higher temps=we're to blame. If the IPCC figures and predictions start from a false base figure, how accurate can they be?

[parmenides3]

I've had several replies from the scientists who frequent the googlegroups 'Globalchange' forum. This is the picture:

Nuclear tests in the 1950s and 602 doubled the amount of atmospheric C14. This meant going from eddie's 1 part per trillion to 2 parts per trillion.

Not enough. If you like, this can be seen as an object lesson in the volumes,quantities and scales we are addressing when discussing global climate.

No evidence was presented to suggest that even the combined effects of 237 atmospheric nuclear tests had any discerniblke effect on the global climate. The only plausible effect, which has not been separated out as an individual signal, would have to come from the dust and particular matter which ground-zero explosions would have thrown up. Even these weren't enough.

Very recent research suggest (using the climate models), that a regional-scale nucear conflict. based on 100 x 1 megaton blasts, mainly over urban areas, would probably have a short-term cooling effect on a global scale. At least some of this would be because of the large quantity of residual burning/fires following such an event.

Though the idea of nuclear testing having a historic effect on the climate is appealing, it is not, nor has it ever been, seriously considered in the literature, even as a minor contribution to GW. Given that the amount of CO2 emitted each year by anthro sources, which in turn is a fraction of the overall carbon cycle, is around 7 gigatonnes, and the sum of all emissions since the 18th century has only increased atmospheric CO2 by around 100 parts per million, and given that this is, in turn, enough to have warmed the climate system by around 1C, it is fairly easy to understand why 250-odd megatonnes of explosion. producing a few hundred tonnes of C14 at most, would not have a discernible impact.

I'm sorry to be the bearer of bad news, as it were, jethro, but the bottom line is that the answer to your original question is a fairly straighforward 'no'.

I still like the idea, though.

:)P

[Just Before Dawn]

Very recent research suggest (using the climate models), that a regional-scale nucear conflict. based on 100 x 1 megaton blasts, mainly over urban areas, would probably have a short-term cooling effect on a global scale. At least some of this would be because of the large quantity of residual burning/fires following such an event.

This is interesting research - I'd be interested to know who carried it out. a 25 kilotonne explosion at or near ground level would create a crater roughly 500m in diameter and 25 metres deep. That's a lot of material thrown up into the atmosphere, though probably inconsequential, even given a major exchange, compared with large volcanic eruptions. Didn't St Helens throw up the equivalent of 20 500 kilotonne groundburst nuclear explosions in ash and other debris.

[parmenides3]

This is interesting research - I'd be interested to know who carried it out. a 25 kilotonne explosion at or near ground level would create a crater roughly 500m in diameter and 25 metres deep. That's a lot of material thrown up into the atmosphere, though probably inconsequential, even given a major exchange, compared with large volcanic eruptions. Didn't St Helens throw up the equivalent of 20 500 kilotonne groundburst nuclear explosions in ash and other debris.

Here you are, from Atmospheric Chemistry & Physics: http://www.atmos-chem-phys.net/7/2003/2007...7-2003-2007.pdf

:)P

[Gray-Wolf]

All I seem to know is the current 'best guess' on N.E.O.'s who appear to be on collision course and what Newton had to say about the conservation of momentum.....

We are led to believe that a very small push on an asteroid, early enough in it's approach, would amount to a large deflection by the time it was supposed to collide with us.....

Newton said something along the line of 'a body will continue in perpetual motion unless acted upon by some external force......'

So, lots of little pushes from certain geographic regions of the planet amassing over time????

Edited May 17, 2007 by Gray-Wolf

[Gray-Wolf]

Just to add to my post above (as the edit has gone) the changes we may have instigated since the testing started (1945) seems to also coincide with the 're-newed' warming trend globally.

Did all those nuclear engines do more than alter the tilt of the planet? could they, being concentrated in 1 or 2 areas on the same side of the planet, have shifted our orbit in a small way? If so how will this manifest over time? will it swing us ever closer to the sun? (some April/May sunshine feels very strong to my old bones!!)