Another View on Climate

My Own View of Global Warming

Archive for the ‘Measurements’ Category

CO2 Concentration and Plant Growth

Posted by greg2213 on November 21, 2011

There was a comment on this WUWT post which I found to be very interesting.

Plants require a certain amount of CO2 to survive. People claim that ice cores taken from Antarctica and Greenland show that CO2 levels during the last ice age dropped to 180ppm. It’s then claimed that a 180 to 280 climb drove us out of the ice age.

The problem is that plants don’t do well at 180. Most just die. Grasses can scrape by, but it’s rough on them. So a period of 100k years of starvation should have had a major hit on grasses and destroyed other plants. Apart from being buried under a whole lot of ice.

Since that didn’t happen it seem reasonable to assume that the CO2 measurements from the ice cores are not accurate.

This is the comment:

Gail Combs says:

…..In past times, during the transition between an ice age and a warm period, atmospheric CO2 concentrations changed by some 100 parts per million (ppm) – from an ice age value of 180 ppm to about 280 ppm during warm periods….

If this was true there would be no trees and certainly nothing like mammoths during the last ice age. At 180 ppm Class 4 plants (grasses) could possibly survive but would not have the “energy” to produce seed. At 200 pm CO2 trees starve (That link of course has since been purged from the internet – SURPRISE – not)

…According to Barnola et al (1987) the level of CO2 in the global atmosphere during many tens of thousands of years spanning 30,000 to 110,000 BP were below 200ppm. If this were true then the growth of C3 plants should be limited at the global scale because their net Photosynthesis is depressed as CO2 concentration in air decreases to less than about 250ubar (less than about 250ppmv)(McKay et al 1991) This would lead to the extinction of C3plant species . This has however not been recorded by paleobotanists (Manum 1991).”

“…Plant photosynthetic activity can reduce the CO2 within the plant canopy to between 200 and 250 ppm… I observed a 50 ppm drop in within a tomato plant canopy just a few minutes after direct sunlight at dawn entered a green house (Harper et al 1979)” Source

Another study on wheat (a grass) in open fields showed the CO2 level 2 meters above the crops was reduced to a near constant 300 ppm during the day but fluctuated during the night. Again indicating a lower threshold of 250 ppm ~ 300 ppm and certainly not indicative of below 180 ppm.

WHEAT: The CO2 concentration at 2 m above the crop was found to be fairly constant during the daylight hours on single days or from day-to-day throughout the growing season ranging from about 310 to 320 p.p.m. Nocturnal values were more variable and were between 10 and 200 p.p.m. higher than the daytime values.

From the people who know and depend on the truth – FARMERS

Hydroponic Shop

…Plants use all of the CO2 around their leaves within a few minutes leaving the air around them CO2 deficient, so air circulation is important. As CO2 is a critical component of growth, plants in environments with inadequate CO2 levels of below 200 ppm will generally cease to grow or produce…

….With the advent of home greenhouses and indoor growing under artificial lights and the developments in hydroponics in recent years, the need for CO2 generation has drastically increased. Plants growing in a sealed greenhouse or indoor grow room will often deplete the available CO2 and stop growing. The following graph will show what depletion and enrichment does to plant growth:

GO TO SITE for CO2 vs Plant Growth GRAPH

Below 200 PPM, plants do not have enough CO2 to carry on the photosynthesis process and essentially stop growing. Because 300 PPM is the atmospheric CO content, this amount is chosen as the 100% growth point. You can see from the chart that increased CO can double or more the growth rate on most normal plants. Above 2,000 PPM, CO2 starts to become toxic to plants and above 4,000 PPM it becomes toxic to people…..

Keith in another WUWT discussion brought up another good point the effect of partial pressure of CO2 at higher elevations on plants.

Speaking of carbon dioxide as plant food there is something else often missing in discussions of CO2 concentration. That is CO2 and its relation to altitude. Humans have trouble breathing near the top of Mount Everest even though the “concentration” of oxygen in parts per million is the same as at sea level. This is because the total density of the air is less so the actual amount of oxygen available per cubic meter is also less. The same holds true for carbon dioxide. Air density at 1000 meters altitude is about ninety percent of its sea level value, and crops grown at that altitude have access to ninety percent of the CO2 at sea level despite the fact that the “concentration” as usually given is the same. Half of the land surface of the earth is about 840 meters above sea level, and the absolute concentration of CO2 there is therefore ninety percent less.

Now when will Engelbeen come to valiantly defend this very important pillar of CAGW? After all low CO2 is the KEY to CAGW.

Dr. Jaworowski tried to do the study to determine the accuracy of the Ice Core CO2 data but the funding was turned down because it was feared his study would “Disprove” the CO2 readings from the ice cores and we couldn’t have that now could we???

Another comment from Gail:

Gail Combs says:

Aside from the plants during the Ice Age showing the CO2 reading are way off there is another elephant in the room.

It is called Water Vapor.

95% of the green house effect is caused by WATER not CO2. It is up to 4% where as CO2 is a puny 0.036% That is why water is left out of the IPCC reports. (Another lie by omission)

Next what did the last ice age to to the water content of the atmosphere???

Glacial Climate and Sea Level
The North American and European ice sheets of the last glaciation began forming after a prolonged cold stage with increased precipitation (mostly snow in this case) took place. Once the ice sheets began forming, the cold landscape altered typical weather patterns by creating their own air masses. The new weather patterns that developed reinforced the initial weather that created them, plunging the various areas into a cold glacial period.

The warmer portions of the globe also experienced a change in climate due to glaciation in that most of them became cooler but drier. For example rainforest cover in West Africa was reduced and replaced by tropical grasslands because of a lack of rain.

At the same time, most of the world’s deserts expanded as they became drier….

So there goes the change of 100 ppm in CO2 having any effect because it would be completely swamped by the water vapor changes! Not to mention the effect of the Milankovich cycles that would directly effect those changes in the amount of water vapor.

The influence of these cycles on insolation (INcident SOLar radiATION) at different latitudes has been calculated by Berger (1991), and Laskar (1993). Below is Berger’s solution for 65 degrees north latitude from the present to 1 million years ago. In the Northern Hemisphere, peak summer insolation occurred about 9,000 years ago when the last of the large ice sheets melted. Since that time Northern Hemisphere summers have seen less solar radiation.

Of course we KNOW the sun has nothing to do with our climate because climate scientists tell us that is so. /sarc>

So as usual these [self-snip] scientists are busy chasing grant money with the get out of peer review CO2 card and not doing real science.

Another commenter:

higley7 says:

It is completely wrong to assume that CO2 measurements from ice cores have anything to do with absolute values. They can show trends and highs and lows, but they are NOT quantitative in any way. Jaworowski, the leading expert has stated that there is 30–50% losses of CO2 during the traumatic process of core extraction. If you back calculate the losses, you end up with CO2 concentrations the same or higher than now.

It is only the IPCC that likes to pretend that ice core data, clearly indirect data, is quantitative—it is NOT!

Posted in Measurements, Plant Growth | Leave a Comment »

On CO2 Being Environmental, Rather than Anthropogenic

Posted by greg2213 on August 5, 2011

On JoNova:

Professor Murry Salby is Chair of Climate Science at Macquarie University. He’s been a visiting professorships at Paris, Stockholm, Jerusalem, and Kyoto, and he’s spent time at the Bureau of Meterology in Australia.

Over the last two years he has been looking at C12 and C13 ratios and CO2 levels around the world, and has come to the conclusion that man-made emissions have only a small effect on global CO2 levels. It’s not just that man-made emissions don’t control the climate, they don’t even control global CO2 levels.

Source: Blockbuster: Planetary temperature controls CO2 levels — not humans

Listen to the speech: “Global Emission of Carbon Dioxide: The Contribution from Natural Sources”


In a nutshell, the issue is rather simple, yet powerful. Salby is arguing that atmospheric CO2 increase that we observe is a product of temperature increase, and not the other way around, meaning it is a product of natural variation. This goes back to the 800 year lead/lag issue related to the paleo temperature and CO2 graphs Al Gore presented in his movie an An Inconvenient Truth.

Source: The Emily Litella moment for climate science and CO2?


Posted in Measurements | Leave a Comment »

Is Increased Atmospheric CO2 Manmade

Posted by greg2213 on September 17, 2010

Naturally the luke-warm to catastrophic crowd says, “YES!” and tends to ridicule any thoughts to the contrary. That “settled Science” thing you know. If so many of them didn’t put Mr. Gore up on a pedestal as The Truth Giver then maybe it would be easier to go along with that “settled science.” Ridicule doesn’t tend to endear people to your argument, especially when all of Mr. Gore’s arguments are so very wrong.

Kinda like the climate sensitivity to CO2, which seems to shrink every decade or two. It was once 6C or so, now it’s around 1C or so. But that’s in a lab. In the real word one has to factor in known and unknown feedbacks into the sensitivity part, so the real number probably approaches zero.

Ok, fell off the track there…

Actually, given all the fuel burning industry of the world I’m perfectly willing to believe that some of the increase is man-made.

WUWT has an article discussion the isotope issue and why that points to a Yes answer.

The carbon of CO2 is composed of different isotopes. Most is of the lighter type: 12C, which has 6 protons and 6 neutrons in its nucleus. About 1.1% is the heavier 13C which has 6 protons and 7 neutrons in the nucleus. There also is a tiny amount of 14C which has 6 protons and 8 neutrons in the nucleus. 14C is continuously formed in the upper stratosphere from the collisions of nitrogen with cosmic rays particles. This type of carbon (also formed by above-ground atomic bomb experiments in the 1950′s) is radio-active and can be used to determine the age of fossils up to about 60,000 years.

The rest: Is it manmade?

The article is followed by the usual few hundred comments, from true believers to true skeptics.

Chiefio discusses isotope ratios here:

It is often asserted that we can measure the human contribution of CO2 to the air by looking at the ratio of C12 to C13. The theory is that plants absorb more C12 than C13 (by about 2%, not a big signature), so we can look at the air and know which came from plants and which came from volcanos and which came from fossil fuels, via us. Plants are ‘deficient’ in C13, and so, then, ought to be our fossil fuel derived CO2.

The implication is that since coal and oil were from plants, that “plant signature” means “human via fossil fuels”. But it just isn’t that simple. Take a look at the above chart. We are 5.5 and plants are putting 121.6 into the air each year (not counting ocean plants). There is a lot of carbon slopping back and forth between sinks and sources. Exactly how closely do we know the rate of soil evolution of CO2, for example?

The rest: The Trouble With C12 C13 Ratios

So we have CO2 from fossil fuels, forest fires, out gassing, vegetative respiration, bazillions of tons of microbes in the soil and the sea, animal respiration, and so on.

Of course, the next important question after proving the the CO2 increase is man-made, assuming that it is, is this: So what?

For a variety of reasons we should be looking to increase world CO2 levels, that much is clear from history. If CO2 does contribute some small amount to warming then perhaps it will help push away that next ice age, which really would be catastrophic.

Posted in Measurements | 2 Comments »

Official US Temperature Station

Posted by greg2213 on January 16, 2010

The US (and much of the rest of the world) has a set of temperature stations, made to exacting standards and carefully maintained. These are used to provide data for both weather calculations and governmental carbon trading and “tax them until they bleed” schemes, er… climate control policy.

Naysayers have been criticizing the stations for various reasons. Obviously these guys are a few marbles short of a full bag and should be ignored. Questioning the dogma, er.. scriptures, er… science of the IPCC (and Co.) is very poor form.

Here’s a pic of one of the official stations used by the NOAA, and probably the UN IPCC and in various hockey stick projections.I guess Al Gore was right, after all!

(From Failblog)

By the way – if you really don’t get the joke, check out

Posted in Jokes, Measurements | Tagged: , , , , | 1 Comment »

CO2 Has Been Higher in the Recent Past

Posted by greg2213 on January 15, 2010

Recent, in this context, is over the last 180 years. Prior to putting a CO2 monitoring station on an active, CO2 spewing volcano, scientists used other methods. Those methods are detailed in a draft paper by Ernst-Georg Beck.

Here are the first three points of his summary

1. There is no constant exponential rising CO2-concentration since preindustrial times but a varying CO2-content of air following the climate. E.G. around 1940 there was a maximum of CO2 of at least 420 ppm, before 1875 there was also a maximum.
2. Historical air analysis by chemical means do not prove a preindustrial CO2-concentration of 285 ppm (IPCC),as modern climatology postulates. In contrast the average in the 19th century in northern hemisphere is 321 ppm and in the 20th century 338 ppm.
3. Todays CO2 value of. 380 ppm, which is considered as threatening has been known several times in the last 200 years, in the 20 th century around 1942 and before 1870 in the 19th century. The maximum CO2-concentration in the 20th century roses to over 420 pmm in 1942.

The rest is here

Posted in CO2, Measurements | Tagged: | Leave a Comment »