Monday, 25 November 2013

Another look at C14 after the bomb

Making science simple so that people can judge for themselves is a challenge for any teacher scientist.  Many people cannot read a graph.   Formulae mean nothing.   They believe in science but want to know they are being told the truth.     I am amazed to hear lawyers and politicans talk about belief  in 'the science'.  It confirms my worst suspicions.

My approach logically is to separate the issues and keep away from complexities.  Professor Love of Melboure University in the 1970s had a wonderful style.   If someone did not understand one explanation, he would find another and then another.   A talented man.   Most just repeat the explanation which makes sense to them and get louder.   In fact people need to understand things in their own terms, based on what they know to be true or science just becomes religion.  Otherwise it is like shouting at someone just because they do not speak English.    You have to swap to their language, as much as you can.

Anyway, here is the now infamous Carbon 14 graph from Wikipedia.

So once again, we look at what this tells us and it tells so much.   For example, it shows that the atmospheric testing after 1965 doubled C14 in the Northern hemisphere.   By the time it crossed the equator, 2 years had passed and it dropped in intensity.    However they seem to meet around 1970 when the French started atmospheric testing in the Southern Hemisphere, an appalling action in which I and many other physicists signed a petition demanding the French government stop.   These French bombs brought the curves together which meant the Southern Hemisphere radiation, specfically C14 had gone up and now matched the northern hemisperhe and they follow each other.    I have to say here that the disappearing concentration is not decay.   That is 5740 years.    The only way for C14 to vanish is for it to leave the atmosphere and that means all CO2.

CO2 is used by plants, disappears into water, is used chemically and comes back, say when the plant rots or the wood burns or the seas return it.   This graph has settled what would have been a major debate on how long it takes for CO2 in the air cycle through the planet.   Half is gone in 14 years.  100 is the reference so half way is 150.   This is called the half life.  

To explain half life, every half life, another half is gone. So ½ is left after 14 years, ¼ left in 28 years, 1/8th left in 42 years, 1/16th left in 56 years.  What this means is that half of all CO2 is gone in 14 years, all man made CO2, all of it.   We could never have guessed this and it needs explanation.

What is more subtle is that the reference point is the 50,000 year old C14 level on both sides.    C14 is created only by cosmic rays and halves every 5740 years.    The system settles when the amount being created exactly matches the amount vanishing through decay.   This is the equilibrium values used by scientists since the 1950s to provide accurate dates for archeological finds.  If any fossil fuel CO2 was still around, this would not be true as fossil fuel CO2 has no C14.

Even without this, you can see that C14 is vanishing back to the old historic level shown as 100%.   So C14 is our radioactive tracer, the same idea used in medicine to see where things go, including Barium meals and radioactive Iodine.   This C14 graph shows us that all the CO2 disappears and it looks, permanently.   

The other observation is the way the curve approaches its final horizontal destination to line up with the 100% level, the age old C14 level.     

The following diagram is a cut down Bern Diagram.   They can be very complex so I am using the simplest.

CO2 is used, stored and exchanged by all these boxed known as carbon sinks.    

Before studying the diagram, know that received opinion is that because the deep oceans take 1,000 years to mix with the roughly 75 metre thick Surface ocean, CO2 cannot be quickly stored there quickly.    So in the conventional model in working out where the CO2 went so quickly you have only 2 choices, the oceans or the land. (Terrestial biosphere)

Consider that the C14 was really absorbed as well as stored in these proportions the air (1.9%) and the Terrestial biosphere (1.3%) and dead leaves and trees(3.6%) and the Surface ocean (2.4%)  you would still have 1.9/(1.9+1.3+3.6+2.4) or around 20% of C14 still left, 120% of the old level     It is just not true.  The C14 is going straight to 100% not 120%.

This is shown as a diagram, with the historic average taken out because it is known.

You can see the computer model heads to equilibrium at 40%, sharing the C14 in proportion between the 3 sinks and ignoring the deep ocean.   It even drops faster at the start, showing how wrong the shape is.   As elsewhere, the real curve is a perfect straight line on log paper.   This means a perfect e-kt curve and one big sink which takes the lot.

This disproves another incidental idea, the idea just used that the rate at which CO2 goes into these things is determined by the amounts in them.   There is no reason to expect that.  

Also consider the plants.    Sure they absorb our C14 tagged CO2, but when they die, it is often returned quickly to the atmosphere, so there would always be some C14 coming back.   There is none of this.  

No, what is needed to explain the graph is a huge reservoir which can  absorb every last bit of CO2 and its tiny C14 tracer without blinking, a reservoir incredibly bigger than the air and the land and even the ocean surface.   Only the deep ocean qualifies.   Conventional wisdom is that it would take a thousand years for the deep sea to absorb anything, simply because we know the layers of water do not mix.   Clearly this does not apply to the gas CO2.    CO2 is dramatically more soluble at high pressure and low temperature, as in the deep oceans.   Remember 10 metres = 1 atmosphere, so even 100metres down is 10 atmospheres.   Plenty to compress CO2.     Unless someone can explain where all the CO2 goes, the obvious explanation is simple enough.   It disappears into the biggest hole there is. 

Now you could say that every CO2 molecule which enters the water should be replaced with another one coming out.  Sure,  there is exchange in both directions, but why exactly the same?   In fact our life experience is that this is not true.     When you breath air in, the CO2 is 0.04%.   When you breathe out, the CO2 is 5%, 100x as much.   You are a terrible polluter.   The exchange was 100:1.    It is how we survive.    We burn hydrocarbons with oxygen and have to get rid of the CO2.   We take in O2 and get rid of CO2 with every breath using the same process.  Our lives depend on high concentrations moving to areas of low concentrations, both to and from air to blood.

The last idea is that somehow we have to explain the modern increase in CO2 for our conclusions to have merit.   Not really.   That is a separate story.    What is clear is that the CO2 from burning fossil fuels is still in the air is as silly as the idea that man made C14 is still in the air.    You do not have to be a scientist to read that from the graph.

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