The Naked Scientists

The Naked Scientists Forum

Author Topic: What is the meaning of 400 ppm (0.04%) atmospheric CO2?  (Read 66375 times)

Offline damocles

  • Hero Member
  • *****
  • Posts: 756
  • Thanked: 1 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #175 on: 03/07/2013 21:35:23 »
Look at the seasonal modulation of CO2. It's more consistent than the seasonal temperature, and peaks in May-June, at the time when anthropogenic CO2 is minimal. If you subtract the underlying recent trend, the peak shifts to July, as you would expect from the dependence of invertebrate activity on temperature.

Alan the seasonal modulation (which peaks in May, not June, because of a rising underlying trend line) is attributed to the extensive Northern deciduous forests shutting down for the winter, and causing CO2 to rise steadily throughout the winter until in spring the new growth restarts the photosynthetic removal of CO2. I am totally mystified by your involvement of the dependence of invertebrate activity on temperature: it is not really apparent why it should work in that direction, and even if it does it is surely a minor factor.

There is further evidence that the seasonal modulation of CO2 is caused by deciduous forests in the Northern hemisphere in the Cape Grim record, which shows a much smaller seasonal modulation. Although there are extensive forests in Tasmania, they are evergreen, and downwind from Cape Grim anyway.
 

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 4707
  • Thanked: 153 times
  • life is too short to drink instant coffee
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #176 on: 03/07/2013 22:57:25 »
So why does CO2 decrease from August to December, when the deciduous forests are closing down?
 

Offline damocles

  • Hero Member
  • *****
  • Posts: 756
  • Thanked: 1 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #177 on: 04/07/2013 01:24:51 »
In my previous post I also forgot to mention that the seasons are reversed in the Southern Hemisphere -- duh!!
The Amundsen-Scott data from the US station at the South Pole shows almost no seasonal modulation.

from alancalverd (Reply # 176):
Quote
So why does CO2 decrease from August to December, when the deciduous forests are closing down?

http://commons.wikimedia.org/wiki/File:Mauna_Loa_Carbon_Dioxide.png

CO2 decreases from August to October in spite of the fact that the deciduous forests are "shutting down" at this time of year because they do not just suddenly stop photosynthesis, but run it down through the autumn months. The rate of decrease of CO2 slows, as the graph above clearly shows, and then the CO2 mixing ratio starts to increase. Once again, your perception of a December minimum is unrealistic because we are looking at a seasonal signal on top of a steeply rising background.

The points on this graph have been obtained by subtracting a running 12-month average from a monthly average, and then averaging that trend across several annual cycles.
« Last Edit: 04/07/2013 01:26:41 by damocles »
 

Offline damocles

  • Hero Member
  • *****
  • Posts: 756
  • Thanked: 1 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #178 on: 04/07/2013 03:23:17 »
Here is a promised response to alancalverd's questioning of the database for the plot:

Quote
But average of what? Not the entire planet, clearly, because we don't have any reliable data of the polar regions before 1900, or of the wet bits of the Pacific Ocean before 1970. But it can't be from a single point either, because of the ridiculously anomalous winter temperatures.

Somebody, somewhere, must surely know what this graph actually represents??

What the graph actually represents is five independent "best guesses" at a single figure to represent a global average trend for climate change. The first three involve raw data from ground stations as well as satellite data. The data are corrected in various ways to try to take account of
bias. The last two are based purely on satellite data, but two different analyses of basically the same raw data.

When the climate scientists try to enter the political debate, they are really in a no win situation.
If they report the raw data, they are subject to accusations of bias, unrepresentative data sets, deniers pointing out why certain raw data might be invalid, etc. If they try to apply corrections to the raw data and average over geographical regions, they are subject to accusations of model error, of massaging the data to fit their preconceptions, of model dependence rather than using the "pure" raw data.

What in fact they do is to work very hard on trying to eliminate bias in their models of the data analysis (note that this is quite a different thing to GCMs) and report in great detail what they did with the raw data and why. Anyone can find this material in the scientific literature, but deciphering it will be a major and unnecessary task for any non-expert, and this is outside my area of expertise; I claim expertise in atmospheric CO2, but not in climate models.

What is shown on the graph appears to be the "global" temperature increase or decrease from a base year from 5 independent sources. The sources are
• GISS -- NASA Goddard figures which use ground station results, correct them where necessary,
and then use satellite results to interpolate between stations.
• NCDC -- NOAA analysis similarly based
• HadCRU -- UK Met Office/University of East Anglia analysis
• RSS -- NASA analysis of raw satellite results from NOAA satellites
• UAH -- An independent analysis of the same raw results at the University of Alabama

I believe that we can take some comfort from the following facts:
• The analyses were very detailed ones by 5 independent teams, genuinely seeking to make a scientific contribution, and with considerable expertise.
• The details of the adjustments made are clearly set out for anyone with the time or energy to read and digest them.
• Although not identical in detail, all five models show the same general trends.

However if anyone really wants to get into this stuff, I would suggest that you first visit wikipedia, and then look carefully at the websites of the various organizations: NASA, NOAA, UK Met Office, and University of Alabama at Huntsville.
 

Offline damocles

  • Hero Member
  • *****
  • Posts: 756
  • Thanked: 1 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #179 on: 04/07/2013 08:23:47 »
From alancalverd (reply # 138):
Quote
The GISS "data" is fascinating. It goes back to 1880, when one continent (Antarctica) was completely unexplored, another (Australia)  had no established meteorological service, and there were no regular reports from anywhere in the Pacific. So how did they deduce a global mean? I smell bullshit!

To set the record straight about Australia, you need to remember that we were not even a nation until 1901! There were various state- or city-based instrumentalities keeping records. These records are archived and available from the Bureau of Meteorology library. In the case of Victoria, my own state, the observational practices were established by Neumayer (a German meteorologist of high repute) in the early 1850s, and records were rigorously kept at the Melbourne Observatory. In 1859 the State Government took over responsibility for the collection of data, and this responsibility -- and the keeping of records, which started to expand until it took in observations from around 25 Victorian country towns -- continued until the establishment of the National Bureau of Meteorology in Melbourne on the first day of 1908.
 

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 4707
  • Thanked: 153 times
  • life is too short to drink instant coffee
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #180 on: 04/07/2013 10:36:19 »
Australia is an extreme example of human habitation globally - practically everyone lives in a tiny strip around the coast and we have almost no useful historic data about the middle of any continent apart from Europe and even less about the oceans than cover 75% of the surface. That's the main problem with historic "data" - it derives from less than 1% of the earth's surface, and most of that very atypical.
 

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 4707
  • Thanked: 153 times
  • life is too short to drink instant coffee
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #181 on: 04/07/2013 10:45:03 »
Reverting to Mauna Loa, they do publish an annual CO2 cycle with the underlying trend removed.  I'm baffled as to why the CO2 level rises whilst the trees are growing, reaches a peak in summer, and decreases as photosynthesis shuts down.  When I was a lad, we were taught that photosynthesis extracts CO2 from the atmosphere, so I'd expect exactly the opposite behaviour if your model is correct (and they haven't moved Hawaii!). Where does the summer CO2 come from? Certainly not human activity, unless you Aussies have found some way of exporting your winter barbie smoke across the equator and halfway round the world.
 

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 4707
  • Thanked: 153 times
  • life is too short to drink instant coffee
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #182 on: 04/07/2013 10:48:53 »
Quote
The Amundsen-Scott data from the US station at the South Pole shows almost no seasonal modulation.

Not a lot of seasonal variation in vegetation or invertebrate activity either. I'm no expert on penguin farts but I doubt that they vary much as they are warm-blooded.
 

Offline damocles

  • Hero Member
  • *****
  • Posts: 756
  • Thanked: 1 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #183 on: 04/07/2013 11:29:11 »
Reverting to Mauna Loa, they do publish an annual CO2 cycle with the underlying trend removed.  I'm baffled as to why the CO2 level rises whilst the trees are growing, reaches a peak in summer, and decreases as photosynthesis shuts down.  When I was a lad, we were taught that photosynthesis extracts CO2 from the atmosphere, so I'd expect exactly the opposite behaviour if your model is correct (and they haven't moved Hawaii!). Where does the summer CO2 come from? Certainly not human activity, unless you Aussies have found some way of exporting your winter barbie smoke across the equator and halfway round the world.

Alan please check this diagram and tell me if that is the graph you are referring to: http://commons.wikimedia.org/wiki/File:Mauna_Loa_Carbon_Dioxide.png

If so, then you must appreciate two things:
firstly that the maximum and minimum are in May and October respectively, not June and December.
secondly that the amount of photosynthetic activity is reflected in the rate of change (slope) of the mixing ratio graph rather than the mixing ratio per se.

The months of maximum negative gradient (high photosynthetic activity) are June and July -- summer months -- while those of maximum negative gradient (low photosynthetic activity) are December, January, and February, the winter months.
 

Offline damocles

  • Hero Member
  • *****
  • Posts: 756
  • Thanked: 1 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #184 on: 04/07/2013 11:54:25 »
Australia is an extreme example of human habitation globally - practically everyone lives in a tiny strip around the coast and we have almost no useful historic data about the middle of any continent apart from Europe and even less about the oceans than cover 75% of the surface. That's the main problem with historic "data" - it derives from less than 1% of the earth's surface, and most of that very atypical.

Australia is the world's driest continent with the least reliable rainfall, and the leading nation with expertise on dryland farming. From very early times, the Bureau of Meteorology was faced with a significant problem -- how to reliably forecast significant rainfall and weather events. Every outback station has a rain gauge and most of them regularly send in rainfall reports to the Met Bureau. There is ample coverage of rainfall right across the continent. But temperature, wind, and barometric pressure is quite another matter. Weather stations were set up in remote locations quite early in the piece to fill in the blank spaces in order to have better data available for forecasting: a survey of the data at http://bom.gov.au will give station locations and the number of years for which data is available.

I think that you will find that the Americas have a similar coverage, although for South American countries the data might be incomplete or of questionable quality because of poverty and political instability.
 

Offline MoreCarbonOK

  • Sr. Member
  • ****
  • Posts: 164
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #185 on: 04/07/2013 18:46:54 »
I note with some amusement that neither JP nor BC (bored chemist) replied on my challenge here:


<mod edit>
Editorialising, non-peer reviewed links removed (yet again!)
The NASA story is  about the thermosphere when it gets hit by solar flares. Here’s the Press release:
http://science.nasa.gov/science-news/science-at-nasa/2012/22mar_saber/
<//end>
henry@moderator
believe it or not, that was in fact the paper I googled for...thanks!
It was just that there was so many "non-peer" reviewed stuff popping up....
I am sorry...

henry@bc & jp

now , to quote from the above paper,  "peer reviewed" & all

For the three day period, March 8th through 10th, the thermosphere absorbed 26 billion kWh of energy.  Infrared radiation from CO2 and NO, the two most efficient coolants in the thermosphere, re-radiated 95% of that total back into space.

 
Why, wow,

did you see that 95% of that 26 billion kWh went back into space? (cooling!!)

now, if you both continue to "believe" in man made global warming,
\

why don't you show me how the testing was done to prove that the net effect of an increase from  0.03% CO2 (300 ppm) to 0.04% (400 ppm) is that of warming, rather than cooling?

hint:Forget about the closed box experiments of those that died a hundred years or so ago. It only shows the warming part.
 

Offline Bored chemist

  • Neilep Level Member
  • ******
  • Posts: 8659
  • Thanked: 42 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #186 on: 04/07/2013 19:42:56 »
Do you mean this "challenge"?

"In fact, as I have been saying all along, by challenging all of you to come with a balance sheet, it is not really even sure anymore  if more CO2 does not cause cooling rather than warming."

Because you did get a reply to that.
I said "Nobody can give an exact figure for 100 ppm will cause x degrees more warming, but they can show that warming will take place (and a simple experiment can show the same thing)" in post 78
Did you not understand?
Since the system is non linear (as you have pointed out) your question makes no sense.
Asking it again doesn't help your case.


"Why, wow,[/size] [/size]did you see that 95% of that 26 billion kWh went back into space? (cooling!!)"
No
Did you see that 5% was not re-radiated (warming!!).
If I give you a hundred buckets of water and take away 95 of them you still end up with more water.
Did you really not understand that?
« Last Edit: 04/07/2013 19:45:48 by Bored chemist »
 

Offline MoreCarbonOK

  • Sr. Member
  • ****
  • Posts: 164
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #187 on: 04/07/2013 20:16:00 »
BC says
and a simple experiment can show the same thing)" in post 78

henry says
you did not show me there (in 78) an experiment that shows the extra amount of sunshine being back radiated to space versus the extra amount being back radiated to earth caused by the extra 100 ppm CO2.

In fact, I suspect you have probably have no idea what type of experiment would prove this conclusively.

You honestly think or believe that 95% is less than 5%?

Let us face it: your answer does not make sense.

 
 

Offline Bored chemist

  • Neilep Level Member
  • ******
  • Posts: 8659
  • Thanked: 42 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #188 on: 04/07/2013 21:10:37 »


"You honestly think or believe that 95% is less than 5%?"
No, of course not. That's why I didn't say that. What you did there was try to use a "straw man" argument.
I don't know why you chose to do that because I have pointed out before that it just makes you look silly.

I think 95% is less than 100% (because it is).

As I said, if the CO2 absorbs some heat and re-radiates 95% of that heat to space then it keeps the other 5%.
That's a net heating effect.
 

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 4707
  • Thanked: 153 times
  • life is too short to drink instant coffee
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #189 on: 04/07/2013 23:52:35 »
Quote
The months of maximum negative gradient (high photosynthetic activity) are June and July -- summer months -- while those of maximum negative gradient (low photosynthetic activity) are December, January, and February, the winter months.

Never mind the gradient, why does the CO2 level start below and increase above the trend level as the weather gets warmer? When trees become dormant they don't release more CO2 than they absorbed when active - indeed the release is negligible compared with the uptake, and in a closed system plants gradually absorb nearly all the atmospheric CO2 until there isn't enough to sustain growth. And as the weather gets warmer, humans discharge less CO2. So what is putting CO2 into the atmosphere as the sun gets higher in the sky? The annual cycle has been going on with the same amplitude and phase even when the underlying trend was much less steep than it is now. 

And regarding Australian temperature records

Quote
The Stevenson screen was first introduced to Australia in the 1880s and was installed everywhere, with a few exceptions, by 1910. Prior to this date, thermometers were located in various types of shelter, as well as under verandas and even in unheated rooms indoors. Because of this lack of standardisation, many pre-1910 temperatures in Australia are not strictly comparable with those measured after that date, and therefore must be used with care in analyses of climate change within Australia.

from Statistics Australia. Rainfall is fairly easy to measure consistently, so those stats are believable, but even with standard Stevenson screens and calibrated thermometers, point records can show point trends reliably but it's extremely difficult to extract meaningful area data or even to compare screens a mile apart if the vegetation and terrain are different. Hence my considerable caution in evaluating historic temperature data even from scientifically sophisticated sources like the Aussie outback.

The art of glider flying is to spot variations in terrain. Brown fields heat up more than green ones, and the contrast produces the thermals that give us the energy to fly. The art of farming is to introduce temporary variations in terrain by rotating crops and grazing. So you might expect the very best point measurements to show a 5 year cycle even if the climate were absolutely constant!
« Last Edit: 05/07/2013 00:08:20 by alancalverd »
 

Offline damocles

  • Hero Member
  • *****
  • Posts: 756
  • Thanked: 1 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #190 on: 05/07/2013 01:27:38 »
Quote
The months of maximum negative gradient (high photosynthetic activity) are June and July -- summer months -- while those of maximum negative gradient (low photosynthetic activity) are December, January, and February, the winter months.

Never mind the gradient, why does the CO2 level start below and increase above the trend level as the weather gets warmer? When trees become dormant they don't release more CO2 than they absorbed when active - indeed the release is negligible compared with the uptake, and in a closed system plants gradually absorb nearly all the atmospheric CO2 until there isn't enough to sustain growth. And as the weather gets warmer, humans discharge less CO2. So what is putting CO2 into the atmosphere as the sun gets higher in the sky? The annual cycle has been going on with the same amplitude and phase even when the underlying trend was much less steep than it is now. 


Seriously Alan? I do mind the gradient! Surely you can work out why from my explanation.
Please note that the CO2 level starts to decrease as the weather is warming up (May), and the decrease continues through the summer months (June through September). But it does not bring the mixing ratio to below par for a few months. Similarly when photosynthesis starts to shut down (October and November), the decrease tapers off and is soon replaced by an increase which continues through the winter (December through April) at a steady rate until the photosynthesis restarts the following spring (May)!
This explains the shape of the monthly correlation graph. It is not the mixing ratio that is linked to photosynthesis, but the rate of change of the mixing ratio!

As for the rest of your post, the effects you point out are totally valid, as are many other similar ones. But that is why climate scientists have made a very serious and detailed effort to eliminate them with model corrections and adjustments (in some cases) or by abandoning point measurements at ground stations in favour of satellite proxies (in others). But you dismiss those efforts as "bullshit"? Which side are you batting for? Or are you simply trying to change a scientific debate into a political one?
 

Offline MoreCarbonOK

  • Sr. Member
  • ****
  • Posts: 164
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #191 on: 05/07/2013 13:55:36 »
BC says
As I said, if the CO2 absorbs some heat and re-radiates 95% of that heat to space then it keeps the other 5%.
That's a net heating effect.

Henry says
ok, ignoring the NO, let us assume all is CO2 up there, @ 0.05% in total
and we had 95% back radiated  to space and 5% absorbed heat:
and that is a ratio 19:1
Now let us make it 0.06% CO2 due to human emission in the future

that will increase the ratio to 19 x 0.06/0.05 = 22.8 : 1.
in which case we have 95.8% being back radiated to space and 4.2% absorbed heat.

That would be a net cooling effect caused by the increase in CO2
(remember we were only talking here about the thermosphere)




 

Offline Bored chemist

  • Neilep Level Member
  • ******
  • Posts: 8659
  • Thanked: 42 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #192 on: 05/07/2013 18:26:37 »
"that will increase the ratio to 19 x 0.06/0.05 = 22.8 : 1."
No, that's just made up stuff.

Once again, you have not understood that the system is non linear.
Please learn about this before posting again.
 

Offline MoreCarbonOK

  • Sr. Member
  • ****
  • Posts: 164
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #193 on: 05/07/2013 19:10:42 »
 BC says
Once again, you have not understood that the system is non linear.
Please learn about this before posting again.
henry says
not once have you spoken to me about "non linear"

but once again you have not  understood that the CO2 is causing cooling from the top (12 hours per day) as proven to you from numerous papers, and warming from the bottom (24/7).
And nobody has provided either you or me with a balance sheet.
Yet you continue to "believe" that the net effect of more CO2 is that of warming, rather than cooling....

Here is something for you from my compatriots (in Holland) to think about:
http://wattsupwiththat.com/2013/07/05/dutch-meteorological-institute-knmi-critical-of-ipcc-suggests-they-are-leaving-out-study-of-natural-climate-variability/


 

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 4707
  • Thanked: 153 times
  • life is too short to drink instant coffee
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #194 on: 06/07/2013 01:23:35 »
Please note that the CO2 level starts to decrease as the weather is warming up (May), and the decrease continues through the summer months (June through September).

not according to the inset on this graph
http://www.google.co.uk/url?sa=i&source=images&cd=&cad=rja&docid=XU7NI4a4HkIJlM&tbnid=AaQqiTlNR_JUkM:&ved=0CAUQjRw&url=http%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3AMauna_Loa_Carbon_Dioxide.png&ei=b2DXUey-N4ul0wXIhYGQCQ&psig=AFQjCNFFGFCI3UdKtRO6OD0LB_77meqJCA&ust=1373155780412660

which clearly shows CO2 increasing as the temperature rises to a maximum in May/June.

Quote
Which side are you batting for? Or are you simply trying to change a scientific debate into a political one?

I'm batting for a scientific approach to climate. That means starting with good data and trying to work out what is going on. It's difficult to find an analogy*, except in the realm of jokes about politicians and statisticians, but just in case nobody has heard it before, the three usual suspects are travelling in a train in Peru when they see a white cow and a black cow.

Politician: "the vast majority of cows in Peru are black"

Statistician: "on a limited sample one can infer that half the cows in Peru are black"

Physicist: "At 0400UTC I saw two bovine quadrupeds. At least one side of one of them was black"

I am a physicist.

There are three sources of good data: satellite measurements (which cover the entire globe on an even grid with a reasonably consistent technique), ice cores (which provide unequivocal historic data from a consistent source at a single point), and a few observatories such as Mauna Loa in places remote from agricultural or urban development. So we need to explain three phenomena: any trends in satellite data untainted by additions, corrections, or smoothing based on nonsatellite data; the historic cyclic sawtooth of temperature followed by CO2; and the actual seasonal variation of CO2.

*hey, I just thought of one! You have been trying to ascertain the distance between two lumps of rock, to set a baseline for a new survey of Victoria. You have historic data based on surveyors' chains, intermediate surveys, triangulation, ant migration times, aerial photography, folklore, pedometers.....and I offer you a laser interferometer. What use do you make of the historic data?
« Last Edit: 06/07/2013 01:54:14 by alancalverd »
 

Offline damocles

  • Hero Member
  • *****
  • Posts: 756
  • Thanked: 1 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #195 on: 06/07/2013 02:09:41 »
...{shrug}...

One last try:

Quote
Quote from: damocles on 05/07/2013 00:27:38
Please note that the CO2 level starts to decrease as the weather is warming up (May), and the decrease continues through the summer months (June through September).


not according to the inset on this graph
http://www.google.co.uk/url?sa=i&source=images&cd=&cad=rja&docid=XU7NI4a4HkIJlM&tbnid=AaQqiTlNR_JUkM:&ved=0CAUQjRw&url=http%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3AMauna_Loa_Carbon_Dioxide.png&ei=b2DXUey-N4ul0wXIhYGQCQ&psig=AFQjCNFFGFCI3UdKtRO6OD0LB_77meqJCA&ust=1373155780412660
which clearly shows CO2 increasing as the temperature rises to a maximum in May/June.

Firstly, the month of maximum CO2 is definitely May, not May-June. Secondly the months of maximum insolation are June-July, and the months of maximum temperature (in the region where the boreal forests are) are July-August.

My point is that photosynthetic activity correlates both with insolation and temperature (insolation is not such a good correlation as temperature, probably because new growth is still "coming on line" in early summer). What is involved in this correlation is actual temperature, not the amount of warming. But photosynthetic activity also correlates well with rate of CO2 reduction. That is, with the rate of change of mixing ratio, not the actual mixing ratio
 

Offline Bored chemist

  • Neilep Level Member
  • ******
  • Posts: 8659
  • Thanked: 42 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #196 on: 06/07/2013 17:05:28 »
BC says
Once again, you have not understood that the system is non linear.
Please learn about this before posting again.
henry says
not once have you spoken to me about "non linear"

but once again you have not  understood that the CO2 is causing cooling from the top (12 hours per day) as proven to you from numerous papers, and warming from the bottom (24/7).
And nobody has provided either you or me with a balance sheet.
Yet you continue to "believe" that the net effect of more CO2 is that of warming, rather than cooling....

Here is something for you from my compatriots (in Holland) to think about:
http://wattsupwiththat.com/2013/07/05/dutch-meteorological-institute-knmi-critical-of-ipcc-suggests-they-are-leaving-out-study-of-natural-climate-variability/



I meant you in the plural sense.
IIRC it was post 144 where it was pointed out that absorption was non linear.
But the point remains that since the system isn't linear (whoever pointed it out)  the naive maths you did isn't valid.




Also, as I already pointed out, repeatedly asking for an impossible balance sheet just makes you looks silly.
 

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 4707
  • Thanked: 153 times
  • life is too short to drink instant coffee
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #197 on: 06/07/2013 19:06:40 »
Damocles

I don't really care whether photosynthesis is driven by insolation, past temperature history, or the arbitrary will of the fairies. The question is, why does the CO2 level increase as the temperature rises?  What is generating the new CO2? It clearly isn't dominated by human activity as the amplitude of the oscillation hasn't changed over recorded time. If the only driver was photosynthesis, the CO2 level would have decreased year on year until all the trees died, several million years before humans evolved. But it didn't. Something was generating CO2, and the rate of generation was and still is temperature-dependent.
 

Offline damocles

  • Hero Member
  • *****
  • Posts: 756
  • Thanked: 1 times
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #198 on: 07/07/2013 05:45:21 »
To summarize what we (i.e. the consensus of atmospheric chemists, with very few dissenting voices) know about atmospheric CO2: basically, there are three quite different effects.

(1) There is a well established and well understood seasonal pattern to the CO2 mixing ratio. It lags the insolation, its ultimate cause, by about 5 months. The chain of causality is mostly down to the extensive boreal forests in the cool temperate zone of the Northern Hemisphere:

insolation (maximum late June)
---> (lag of 0.7±0.5 months due to new growth coming on line)
photosynthetic activity (maximum mid July)
---> (lag of approximately 3.0 months because of 90° phase shift associated with time to achieve a minimum with a quasi sinusoidal rate of change)
CO2 mixing ratio minimum near boreal forests (mid October)
---> (lag of 0.7±0.3 months associated with thorough intrahemispheric mixing, Hawaii not being anywhere near the boreal forests)
CO2 mixing ratio seasonal minimum observed at Mauna Loa observatory (late October/early November)

(2) There is a rather less well understood lag of CO2 mixing ratio behind temperature by 50-300 years over the historical ice-core record of 4 ice ages and 4 interglacials in the last half million years, with ice age CO2 levels typically being around 200 ppm and interglacial levels being around 280 ppm. There have been several plausible hypotheses about why this should be the case, but it is a matter for continuing scientific enquiry.

(3) There has been a very steep rise in CO2 starting with the Industrial Revolution in Europe in the mid 19th century. It is certainly anthropomorphic. How do we know this?
• Because we can do carbon accounting and point to how the rise in atmospheric CO2 corresponds to consumption of fossil fuel
• Because if it were a natural effect then we would expect that it would be heralded by some extreme temperature rise, and this is certainly not in the temperature record
• Because it has taken CO2 mixing levels well outside the regime that has operated over the previous half million years or more, with CO2 levels varying between 200 and 280 ppm up to 400 ppm.
• Because there are much more subtle indications from isotope ratios that most of the additional CO2 burden in the atmosphere indicates that most of the increasing CO2 mixing ratio is coming from fossil fuels rather than living (i.e. recently dead) plants.

The fact that the recent rise in CO2 mixing ratio is anthropogenic is really a no-brainer!
 

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • Posts: 4707
  • Thanked: 153 times
  • life is too short to drink instant coffee
    • View Profile
Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #199 on: 07/07/2013 12:20:25 »
Quote
(1) There is a well established and well understood seasonal pattern to the CO2 mixing ratio. It lags the insolation, its ultimate cause, by about 5 months. The chain of causality is mostly down to the extensive boreal forests in the cool temperate zone of the Northern Hemisphere:

That would explain a decrease in CO2 level. It doesn't explain an increase. Plants do not exhale carbon dioxide. Where, please, does the new CO2 come from in the months leading up to May? There's no doubt that human activity adds CO2 to the atmosphere, but most of that addition takes place when the plants are dormant, so you'd expect to see a maximum in winter, not summer, surely? And the amplitude of the oscillation appears to be independent of the gradually increasing mean.

Not sure what you mean by CO2 "mixing ratio". Mixed with what? The Mauna Loa data just talks about absolute concentration of CO2 - or is that the same thing?

 

The Naked Scientists Forum

Re: What is the meaning of 400 ppm (0.04%) atmospheric CO2?
« Reply #199 on: 07/07/2013 12:20:25 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums