SKEPTICS, please answer this:?

Question

WHY would the CO2 we emitt (30,000,000,000 tonnes per year) not have a greenhouse impact on the earth climate?

Without CO2, the Earth surface would be at an average temperature of -18°C (0°F). So how can we possibly add 20% CO2 into the atmosphere and the carbon cycle without causing a global temperature increase?

What offset (according to you) the effect of this additional CO2?

JIM: have you ever had the chance to have some lab work about spectral absorbtion at school ?

HEATHER: The vapor concentration in the atmosphere is set by the global level of moisture saturation in the air... which depends on the global earth temperature.
It is what is called the enthalpy (H) of moistured air. This enthalpy is heat energy. As such it is a result of the temperature level, not the cause.
Anybody who had thermodynamics knows it.

Answer 1

As you know I'm not a skeptic, so does this bar me from commenting on your question?

The answers you have received thus far are quite predictable and show either a) a lack of scientific understanding or b) a refusal to accept facts.

I would point out that it's not the absence of just CO2 but all greenhouse gases that would cause temperatures to fall by 33°C (i.e. to the levels you mentioned). CO2 is responsible for 72.294% of the greenhouse effect after water vapour is removed from the equation. If we take water vapour into account it's not possible to be so precise because, as you know, the role of water vapour is a variable one due to overlapping forcings.

We can assign a minimum and maximum value to the contribution of water vapour, these values would be 36% and 66% respectively. When we factor in clouds the total water vapour contribution lies between 66% and 85%. All things taken into consideration, the role of CO2 is therefore between 10.8% and 24.6% (a range often assigned to CO2 is 9% to 26% but the science has improved a little and we can now narrow it down slightly).

For millions of years, levels of CO2 varied between 190 and 280ppmv, they're now at 387ppmv and rising by 2ppmv a year. The role of humans has been to increase atmopsheric concentrations of CO2 by close to 40%, pretty much the same as the overall increase in respect of all greenhouse gases.

The reason for the increase being that the 30Gt of CO2 emitted each year, along with the 12Gt of other greenhouse gases, is way beyond anything that natural processes can handle. Nature has a built in 'buffer' which enables an excess 3Gt of CO2 to be absorbed each year, if this was all we were emitting there wouldn't be a problem but we're emitting 10 times the amount that nature can handle and this surplus is accumulating in the atmopshere.

The fact that greenhouse gases retain heat is easily proven and in one of my recent answers I explained how a few simple household items can be used to demonstrate this.

Given that anyone can easily prove to themselves that the greenhouse effect is real, it really is a pointless exercise attempting to refute that increasing levels of greenhouse gases won't cause the planet to warm up unless some compensatory factor can be found. And I think it's pretty safe to say that if such a factor existed we'd have found it by now - unless of couse, someone has secretly built an SO2 factory that belches billions of tons of SO2 into the atmopshere that somehow has gone un-noticed.

PS I love Mr Jello's answer, it seems to imply that unless a linear relationship exists then there is no relationship at all. We could apply that logic to population expansion and 'prove' that we don't exist. And as for the planet cooling down since 1998... I'm not even going to go there.

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TO ACIDMAN
A very valid point about SO2 and it does indeed lead to global cooling because the molecules have a reflective property that reflects incoming shortwave solar radiation back out into space before they reach us. However, atmopsheric concentrations are small and not enough to compensate for rising levels of CO2 (although they do have a role to play).

The last time SO2 cooling overshadowed CO2 warming was in 1993 following the 1991 eruption of Mount Pinatubo. As happens following major volcanic eruptions, the planet cools for a couple of years.

Ironically, the passing of the Clean Air Acts that saw the removal of much industrial and domestic SO2 has allowed global warming to advance at a greater rate. Back in the 1950's and 60's there was so much SO2 in the atmopshere that it led to 'global dimming'.

Volcanoes do produce CO2, the average annual total is less than 1% of the human production.


TO BEN O
If you look at my figures (or go to any credible website and get your own figures) you'll see that CO2 levels have increase by close to 40%. The natural MAXIMUM in the millions of years prior to the onset of industrialisation was around 280ppmv, it's now 387ppmv (July 2007) - that's an increase of 38.2% (my exact wording was 'close to 40%', bear in mind that this is the MINIMUM human contribution. Contrary to what you might think I do actually play DOWN the human contribution).

You asked why temps haven't increased to 41°C (above the minimum) - why should they? The mechanisms that cause warming and cooling are complex (far too compex to explain here and without the use of diagrams and animations). The bottom line is that an X% increase in gas Y does not cause an X% increase in absolute temperatures over and above the base minimum. No-one has ever said, or even implied, that it will.

A veryt basic analogy would be to compare it to yourself on a cold day. You're 37°C, let's assume it's 0°C outside (freezing point). You put on a jacket and go outside, you're not particularly warm but not cold either - the temp inside the jacket is about 25°C. You put on another jacket and double the insulating layer, you're not going to suddenly warm up to 50°C even though you've now got twice as much insulation. Why? Because the insulative effect is governed by the 'law of diminishing returns' and b) the heat source remains constant.

Increasing levels of greenhouse gases does not CREATE more heat, it RETAINS a greater proportion of the available heat. See also the comments made by JBTASCAM about this.


TO JBTASCAM
I hadn't read your answer before I added my comments to JIM O but we're both saying more or less the same thing - doubling levels of CO2 doesn't lead to a doubling of temps.

You do say that there hasn't been a wrming trend for the last 10 years - there has.

Here are the figures based on a ten year mean expressed as an anomaly from the base period mean...

1998 - 0.381°C
1999 - 0.424°C
2000 - 0.451°C
2001 - 0.476°C
2002 - 0.504°C
2003 - 0.526°C
2004 - 0.514°C
2005 - 0.532°C
2006 - 0.559°C
2007 - 0.570°C

To convert to absolute temperatures add 14°C. I've used a 10 year mean based on the most definitive global termperature record available, I could have used any period and any dataset and the trend would be the same (the figures would have been slightly different but the trend wouldn't). Note that year on year the only time the average global temperature didn't increase was 2004.

Answer 2

Well for starters lets look at your statement.

"Without CO2, the Earths surface would be at an average temperature of -18°C (0°F). So how can we possibly add 20% CO2 into the atmosphere and the carbon cycle without causing a global temperature increase?
"

There are plenty of climatologists that put the contribution of water vapor and clouds in the greenhouse process at an average of 95%. Taking all of the CO2 out of the atmosphere would result in a temperature drop of a few degrees but not fifty. And very early in the curve of atmospheric CO2 concentration( which we have already past), the absorption bandwidth becomes saturated, so that every molecule of CO2 added to the atmosphere has less effect than the previous.

The other unknown element is convection, how much of earths energy is transferred from the surface to the atmosphere via convection. Until this is answered you will NEVER be able to say with any certaintity how much heat the human contribution of greenhouse gases are capturing. They are just best guesses.

Answer 3

Ok first of CO2 is logarithmic that is the more you put the less effect it has, there are studies that may, note I said may the study hasn’t been reviewed yet, we may have already reached the level where CO2 has done all it can do as far as raising the temperature. By the way your -18 is without greenhouse gasses the average temperature would be -18 that is with no greenhouse gases, no water vapor, no methane, no CO2 etc.

Water vapor, in all forms makes up about 90 to 95 percent of the greenhouse gas, with CO2, methane, N2O, then miscellaneous gasses. Methane is a much more powerful then CO2 as a green house gas. Of course you could disagree with me, but then you’d have to toss out the IPCC report too.

But why you do put so much faith into the theory of man-made global warming?

The IPCC summary report stated they would make SURE the report matched the summary, a little backwards but it must be the new science. You know the new science where you draw you conclusions first and then find data to support it.

The IPCC still hasn’t retracted or discredited the hockey stick graph.

The IPCC used models that can’t be set back more the a few hundred years and come to today’s climate.

The IPCC has tried erase the medieval warming period (see the hockey stick graph).

The IPCC has left out that we are still under the 3,000 year average for global temperature.

I could use the IPCC data right now and support a theory that says as the temperature increases so does CO2 levels, I think I can make a better case for that then the IPCC can for man-made global warming.

Answer 4

You said without CO2, the Earth's surface would be -18 degrees celcius. As we increase the concentration of CO2 by 30%, why don't we get a 30% increase in temperature change?

The natural greenhouse effect is estimated at 33 degrees, why haven't we increased that effect to 43 degrees. In fact why haven't we had an increase in global temperature that can't be explained by natural phenonema? The answer is obviously, atmospheric CO2 isn't as bad as the believers try to make out.

(edit) Trevor, you have written more than everyone else put together, but you don't seem to have addressed the question at all.

I was writing retorically.

The question is based on a false premise. If we didn't have CO2 in the atmosphere, the temperature wouldn't be -18 degrees celcius.

This is obvious because the amount of CO2 in the atmosphere can increase significantly without a significant increase in temperature.

There is nothing wrong with the quality of answers. I don't think Dr Jello is implying what you think he is. Not everyone shares your faith.

Answer 5

It probably DOES have an effect, but it has been GREATLY exagerated.


"Without CO2, the Earth surface would be at an average temperature of -18°C (0°F)."

I don't believe that. As a percent of total greenhouse gasses in the atmosphere, CO2 represents 9% of the total greenhouse effect.

"What offset (according to you) the effect of this additional CO2?"

No one really knows the answer to that because of the large number of variables that affect each other in ways we don't understand.

Answer 6

You talk about CO2 as if it is the ONLY greenhouse gas. Water vapour is the most common GHG and it absorbs more across the IR band than CO2 does, making it a more effective GHG.

When you're talking about differences in CO2 as compared to water vapor in the atmosphere, you're talking about the differences between parts per million (of CO2) and parts per hundred (%, of water). Water vapour absorbs more heat than CO2 and it is orders of magnitude more abundant in the atomosphere.

The so-called greenhouse effect is a misnomer. In a greenhouse, there is a physical barrier to convection. Atmospheric gases don't trap IR radiation in that manner. The absorb and emit radiation at specific wavelengths, but these emitted wavelengths don't get trapped once they're emitted.

I'm sorry that my reference has to be a Wiki article, but it does have a nice explanation of the greenhouse effect as well as IR spectra of various GHG's.

EDIT: I'm not debating that point. But it is still a fact that the amount of water vapour in the atmosphere at any given time is STILL orders of magnitude more than CO2 concentrations.

Taking thermodynamics was part of my degree in Chemistry. As was Environmental Chemistry.

Answer 7

For what it's worth, Trevor...

Volcanoes are spewing millions of tons of SO2 into the atmosphere every year...and Kilauea has been erupting since the 80s. Then there are all those other volcanoes that keep popping off that are also contributing to the amount of SO2.

Mammoth Mountain, in Californica has a vent that blows out CO2, and there is also a campground in the Mammoth Lakes area that's been closed for several years due to increased CO2 emissions.

Don't get me wrong, I'm not saying that humans haven't impacted the environment on a global scale...I'm just pointing out several areas where natural emissions occur.

Just for informational sake: I work in a control room, operating an acid plant - which is a fancy pollution control system for a copper smelter. The gas coming off the furnaces is about 350,000 ppm SO2. I dilute it down to about 135,000 ppm with fresh air before it enters my acid plant. Through my acid plant, the SO2 is converted to SO3, and then made into sulfuric acid.

During a "good" shift - 12 hours - I'll make about 250,000 gallons of 94% sulfuric acid...

...stopping who knows how many thousands of tons of SO2 from entering the atmosphere...

As it stands, that 135,000 ppm (at about 165,000 ncfm of air/gas flow into my acid plant) of SO2 is reduced to a typical emission of about 65 ppm SO2.

Answer 8

I have one for ya.. could it possibly be the sun. You have great correlation between temperatures and the sun.. People have tried to disprove this theory, but I feel it was always to no avail. We have been cooling since the Solar max started headed towards it's Solar minimum which hit in 2006. Now granted 2005 has been the hottest year since 1998 but that can be accounted for with El Nino's and La Nina's. No skeptic that I have talked to has ruled out the possibility of man contributing but man is not the entire cause!! I mean the CO2 levels have been higher than today with temperatures not correlating. I just need more proof than CO2!!! Methane would be a good since 3,000 years ago methane levels were 600ppb and now it's 1600ppb now that's something to study.

Answer 9

If CO2 is the primary greenhouse gas, and stipulating that CO2 levels are now 20-30% higher than they have ever been, then why are global temperatures still roughly 3 degrees Celsius below past global temperature maximums, all of which occured at lower levels of CO2 than currently present in the atmosphere?

Answer 10

As usual, you've couched your question in bad science, but hey, you can't be expected to be accurate when you're being histrionic.

The TOTAL amount of warming expected from raw CO2 concentrations being doubled from 280 ppmv to 560 ppmv is about 1.5 degrees C.

The argument, then, is whether there are more POSITIVE feedbacks or NEGATIVE feedbacks, and whether the current levels of 380 ppmv are anywhere near dangerous.

Unfortunately for the AGW crowd, the Earth doesn't seem to be warming anymore. The DATA (unlike the "computer MODELS aka VIDEO GAMES") show that there has been no trend for the last 10 years.

Oh darn the DATA! How dare it conflict with the computer models?