Tuesday, May 05, 2015

2 - 3 < 0 Or Why Natural Sources and Sinks Are Not the Source of Increased Atmospheric CO2

Of course, this is an old argument. Eli prettified it up a bit at Bishop Hill and repeats the argument here in polite company (You, yes you in the back.  Stop laughing).  Apologies to the original source

Postscript:  Dikran with the algebra at QuantPaleo


Δ - is the change in atmospheric CO2, over any period of a year or greater  
He - is the emission of CO2 due to humans burning fossil fuel, 
Ne -  is the natural emissions of CO2 from all sources. Here, Eli is using the word nature to stand for everything except CO2 generated by burning fossil fuels. 
Na - is the total natural absorption of CO2,
We can simply write
Δ = He + Ne - Na
This is an accounting identity. Rearrange the equation by subtracting He from both sides of the equation
Δ - He = Ne - Na
We know that emissions from humans burning fossil fuel He are greater that the change in atmospheric CO2 by about a factor of 2, so He > Δ and (Δ - He) is negative.
0 > Δ - He = Ne - Na
This means that Ne - Na must be negative, so the natural emissions must be less than the natural absorption or, Ne < Na, and nature is not the source of the observed increase in CO2 since the amount of CO2 emitted into the atmosphere by everything except burning fossil fuels is less than the amount of CO2 absorbed from the atmosphere by both physical and biological processes.

See how easy it is. It is only necessary to know two things.

First that the change in CO2 atmospheric concentration, Δ, is positive. That comes from the Mauna Loa observations, ice cores, you name it. Second that emissions due to burning of fossil fuel would increase the amount of CO2 in the atmosphere more than the observed increase (Δ-He < 0).

That is known both from the source term, the amounts of fossil fuels mined (coal and tar sands), pumped (oil and gas) and a sink term, the amounts burned to generate electricity, run cars and trucks, etc. I f anything the measures of He are underestimates.


Unknown said...

Typo to be fixed:
We can simply write

Δ = He + Ne - Na

This is an accounting identity. Rearrange the equation by subtracting He from both sides of the equation

Δ - He = Ne - Na

Barton Paul Levenson said...

Plus, there's the radioisotope signature. The new CO2 is deficient in both 13C and 14C, indicating that the source is a) from plants, and b) really old. I.e., from fossil fuels.

Anonymous said...

Indeed, there are multiple lines of evidence as to why it is almost certainly anthropogenic. That's why I find it extremely difficult to takes those who suggest that it might not be, seriously. It's not even as if it's all that complicated.

Pete Dunkelberg said...

IOW "increased CO2 is natural" won't fly without fairies.

Aaron said...

How long does carbon have to sit under permafrost before it starts to look really old?

Will we know when carbon buried only a couple of million years ago is being released by melting permafrost or decomposing clathrates on the deep sea floor?

Will we know when carbon buried only 200,000 years under permafrost or as clathrates on the sea floor is being released?

How deep do the Siberian fires have to burn before their radioisotope ratios are similar to that of fossil fuels?

How old is the methane under the East Siberian Sea?

Boro Nut said...

Algebra has happened many times in the past. Mankind can't control the algebra. In the 1970's they were saying that A+B=C. Now they say it equals X. And anyway, algebra is good for us.

Bernard J. said...

For giggles it seems Judith Curry is hosting a similar "discussion". I can only assume that it is for giggles, because if it's a serious attempt to completely overturn the best understanding about the cause of atmospheric CO2 increase, then one can only conclude that parsimony and facts are irrelevant to Curry's approach to science.

Kudos to ATTP and Dikranmarsupial for their efforts to educate the apparently uneducable.