Atmospheric CO2 question

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Please no politics, I'm trying to understand something here. According to what I'm reading on Wikipedia, atmospheric CO2 has increased from 280 ppm in 1750, to 395.4 ppm in "recent" times (no year given), and increase of about 41%. Looked at another way, CO2 has increased from .028% (or .00028) of the atmosphere, to .03954% (or .000395) of the atmosphere. For the sake of my question, I'm assuming that these numbers, i.e. the increase in CO2 since 1750, are correct.

The questions I have are as follows: Is there a threshold at which the "greenhouse effect" is increased or decreased by the presence or absence of a particular gas? In other words, would 1 part per million of CO2 in the atmosphere raise the surface temperature of the earth by a theoretical or measurable amount, or is a certain atmospheric concentration required before effects are seen?

I realize that the greenhouse effect exists and helps to keep the earth as temperate as it is. I also realize that other gases, such as water vapor, methane, and others, have an effect. My current question is about CO2.

The atmosphere of Venus is 96% CO2, and it's hotter than blazes, to use a technical term. The surface temperature of Mercury can range from -275 F to + 840 F, and Venus, which is farther from the sun, stays at about +870 F all of the time. Mars, which is much farther from the sun, has temperatures ranging from a low of about -243 F at the poles, to a high of around +68 F at noon at the equator. The atmosphere of Mars is also about 96% CO2, but its atmospheric density is also extremely low, while the atmosphere of Venus is very dense.

So the question has some complexities. I already know the politics, and I have my own opinions. I think that there are people that can answer my questions above without injecting politics into it, and I hope some will participate before this dissolves into the inevitable flame war. Also feel free to PM me on this, if you think it's necessary to avoid conflict.

Here's hoping.
 
Yours is a very specific question, asking the effect of one variable while keeping other variables constant. Only a thorough search among the many scientific studies may yield an answer. I don't believe anyone here has that at their fingertips. Good luck finding an answer.
 
My guess would be that if you want an answer to your question you should look at the history of the earth. What were the C02 levels thousands of years ago?
 
Earth has experienced ice ages hundreds millions of years ago with CO2 levels of 2000-8000 ppm. So will rising CO2 levels contribute to the next ice age...rather than global warming? Previous Epochs show earth's animal and plant life to be just fine with CO2 levels at 1,000 ppm. The last ice age 12,000 yrs ago may have had slightly higher CO2 levels than today...by one source I read. CO2 is just one small factor in the earth's climatology. Outside influences from the Sun are certainly very important. Trying to assign anything accurate to the 150-300 years of man's industrial age is quite a leap. Then you'd also have to explain periods of warning and higher CO2 when man was not industrialized.
 
Originally Posted By: Kestas
Yours is a very specific question, asking the effect of one variable while keeping other variables constant. Only a thorough search among the many scientific studies may yield an answer. I don't believe anyone here has that at their fingertips. Good luck finding an answer.


Yes, very specific. I am continually hearing about "carbon emissions", which in the case of cars I assume to be CO2. If diamonds were falling out of my tailpipe, I'm not sure that would be a problem. I realize that the "carbon emission" of cows is methane, but I'm asking about C02, which is the gas I hear mentioned most often.

I also am asking if there's a threshold value at which CO2 begins to exert a greenhouse effect, since it's one thing to have a 960,000 ppm concentration of CO2 in the atmosphere (Venus), and another think to have a 395 ppm concentration (Earth). So does 1 ppm make a difference? 10 ppm? and so on.

Just looking for some truth, if it's "out there".
 
Originally Posted By: 69GTX
Earth has experienced ice ages hundreds millions of years ago with CO2 levels of 2000-8000 ppm. So will rising CO2 levels contribute to the next ice age...rather than global warming? Previous Epochs show earth's animal and plant life to be just fine with CO2 levels at 1,000 ppm. The last ice age 12,000 yrs ago may have had slightly higher CO2 levels than today...by one source I read. CO2 is just one small factor in the earth's climatology. Outside influences from the Sun are certainly very important. Trying to assign anything accurate to the 150-300 years of man's industrial age is quite a leap. Then you'd also have to explain periods of warning and higher CO2 when man was not industrialized.

Wrong. The Earth's CO2 levels have been between 220ppm and 360ppm in the Quaternary Period (2.5 millions of years ago) There were maybe 11 ice ages in that period of time. Earth temperature varied in that time depending on increasing and decreasing CO2 levels. These temperatures varied in response to weathering of rocks (decreased CO2) and Milankovich Cycles. Changes ocurred slowly over periods of 10's and 100' of thousands of years.

Nothing resembling changes in the last 100 years. Read good information and not the [censored] that comes from heartland.org.
 
Originally Posted By: Stelth
Just looking for some truth, if it's "out there".


If it is out there it certainly wouldn't be on an automotive forum like Bobistheoilguy. I haven't seen many scientists who study earth's climate chime in on previous threads on global warming.
 
Sensation and science are two different and fundamentally incompatible things and thrusting singular, non-comprehensive, yet alarming facts around into the public domain, which has a partial and rote understanding at best, are only able to make inconclusive deductions based entirely on picked and 'fed' facts. Mars and Venus have entirely different atmospheric gas compositions than Earth obviously. I've never seen an answer to the threshold question, but hypothesize that it would have to be pretty extreme to impart a global effect all by itself.

In terms of CO2, let us consider for a moment the amounts of methane gas (and other light hydrocarbons) reaching the upper atmosphere alone and being oxidized at the top of the atmosphere by light to produce CO2 and water and heat. Both oxidation of hydrocarbons and condensation of water vapour (on the particulates of a given condensation nucleate) are liberating heat into the upper atmosphere. Does one think that this would have a greater impact on the immediate "climate" vs migrating CO2 from ground level??

Al is right, the last 100 years is unusual. Don't take that fact for granted.


Basic Wikipedia info regarding the greenhouse efficacy of CO2 vs methane.
https://en.wikipedia.org/wiki/Atmospheric_methane#Methane_as_a_greenhouse_gas
 
Originally Posted By: Al

Wrong. The Earth's CO2 levels have been between 220ppm and 360ppm in the Quaternary Period (2.5 millions of years ago) There were maybe 11 ice ages in that period of time. Earth temperature varied in that time depending on increasing and decreasing CO2 levels. These temperatures varied in response to weathering of rocks (decreased CO2) and Milankovich Cycles. Changes ocurred slowly over periods of 10's and 100' of thousands of years.

Nothing resembling changes in the last 100 years. Read good information and not the [censored] that comes from heartland.org.


I'll leave it to you to dispute these dozens/hundreds of references and scientists

I've always liked Bob Hoye's charts on so-called man-made global warming

More Hoye

Global warming is going the way of "peak oil" of the early 1970's. Weren't NY and Miami already supposed to be underwater by now based on predictions of 25-40 years ago? I also value the opinions of trained experts who don't earn their living via the "carbon industry," or through carbon related grants, or professional climate warming academia. The earth surely has continual climate change. Global warming and cooling are inherent parts of that.
 
Originally Posted By: Stelth
I am continually hearing about "carbon emissions", which in the case of cars I assume to be CO2. If diamonds were falling out of my tailpipe, I'm not sure that would be a problem. I realize that the "carbon emission" of cows is methane, but I'm asking about C02, which is the gas I hear mentioned most often.

I also am asking if there's a threshold value at which CO2 begins to exert a greenhouse effect, since it's one thing to have a 960,000 ppm concentration of CO2 in the atmosphere (Venus), and another think to have a 395 ppm concentration (Earth). So does 1 ppm make a difference? 10 ppm? and so on.

Just looking for some truth, if it's "out there".
Look at where carbon is located in the periodic table of elements. It's in that particular location for a reason. You may need to educate yourself on the periodic table and the people who figured it out to understand the Big Picture.

"Carbon emissions" is now a politically-loaded-term. So I'll skip to the facts that all life on Earth is carbon-based. Both humans, animals & plants. In the ocean and out. Carbon is the backbone, literally, for life.

Diamonds are far from 'carbon emissions'. Carbon is an element that has more than one form. Diamond is one of those. Graphite is another.

I think you're asking about a CO2 'tipping point', where perhaps Earth's climate would turn into Venus, or Mars or Mercury? That'll never happen. CO2 will never 'run away' in Earth's climate. Why? There's far too many negative feedback mechanisms. If there wasn't, we'd of never made it this far nor have this conversation.

Finally, there are reasons why Earth is Earth, Venus is Venus, Mars is Mars and Mercury is Mercury. Likewise Earth will never turn into one of those...and one of those will never turn into Earth. There are many, many reasons why this is so. One of the reasons is that about 71% of Earth's surface is covered in water, and the major majority of it is saltwater. Another major reason is that Earth has a molten core. Another reason is our position in the solar system. Yet another reason is because Earth's rotation & stability is greatly augmented by our Moon.

I could go on and on.

You might be interesting in doing some research on planetary science and astrophysics.
 
Originally Posted By: 69GTX


I'll leave it to you to dispute these dozens/hundreds of references and scientists

I've always liked Bob Hoye's charts on so-called man-made global warming

Global warming is going to the way of "peak oil" of the early 1970's.

About as much true science in those articles as in my glass of ice tea. I love reading real science. It my life. Read whatever you want.

The U.S. National Academy of Sciences affirms the truth of the matter. Those are 2500 scientists who all rank at the top of world elite scientists.
I could go on forever with legitimate organizations but what's the point.Those that want to learn will..they will seek out legitimate science.

Check into the finances of the Heartland Institute for a good chuckle.
 
Originally Posted By: 69GTX
Nicely said Sleddriver.
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OP, you've crossed the first Rubicon so to speak in analysing the issue. You've identified that things have changed...and we are pretty well responsible for it. We as a species have altered the atmosphere to a measurable degree.

As to what that means, I've read as much science as I can find, agree with some of it, disagree with some of it.

As to thresholds, I don't know, but we are in the middle of an experiment that we will see the results of, so I'm more in the mind of prudent conservation of resources, firstly as they are finite, and secondly just in case...

While the earth has had many cycles, some lagging, some leading, the leading ones seem to not bode well for those around at the time.

https://www.sciencedaily.com/releases/2017/06/170619151530.htm
 
Climate "science" is nothing of the sort!

One cannot correlate pollution or CO2 and long term global climate.

We will get the pollution issue under control.

Furthermore, the "science" of climate is not settled. We have been utterly unable to do anything other than observe. And we don't fully understand what we are observing. That (observation) is not science, it's not a double blind study with controls and accurate results based on controls. The scientific computer models are estimations (yes, guesses) based on best guess data. That's not science either.


I make no claims to "KNOW" that CO2 or other pollutants DO NOT affect global climate. I do claim that no ACTUAL science has been done to prove that CO2 does affect global climate.
 
Originally Posted By: sleddriver
One of the reasons is that about 71% of Earth's surface is covered in water, and the major majority of it is saltwater. Another major reason is that Earth has a molten core. Another reason is our position in the solar system. Yet another reason is because Earth's rotation & stability is greatly augmented by our Moon.

I could go on and on.

You might be interesting in doing some research on planetary science and astrophysics.


I'm glad you brought up the Earth's water covered surface. Actual science can be done with atmospheric air temperature and water temperature. Very interestingly, there is much discussion about increasing ocean water temperatures. However, very little discussion as to the method of heating involved (hint: it's solar irradiation) . Air temperature has precious little affect on ocean temps. In fact, a slight increase in air temperature, say 1 degree F, may have no measurable affect on ocean water temperature. As it takes Water stratifies strongly and does not mix. Warm water rises to the top, just like in our home water heaters. (that run out of hot water suddenly) .

Bottom line: Incoming IR heats the oceans.
 
Originally Posted By: Cujet
Climate "science" is nothing of the sort!

One cannot correlate pollution or CO2 and long term global climate.

We will get the pollution issue under control.

Furthermore, the "science" of climate is not settled. We have been utterly unable to do anything other than observe. And we don't fully understand what we are observing. That (observation) is not science, it's not a double blind study with controls and accurate results based on controls. The scientific computer models are estimations (yes, guesses) based on best guess data. That's not science either.


I make no claims to "KNOW" that CO2 or other pollutants DO NOT affect global climate. I do claim that no ACTUAL science has been done to prove that CO2 does affect global climate.


No, it's settled, dude. Nobody cares what you "claim". Because you have absolutely no qualifications...
Theodoric-of-york.jpg
 
Originally Posted By: Nickdfresh


No, it's settled, dude. Nobody cares what you "claim". Because you have absolutely no qualifications...



As an engineer, I do understand the scientific method. We cannot experimentally test it via the scientific method, therefore, it's not science. Nor is it scientific observation, the observation experimental results.

Climate science is really only simple observation, nothing more. Possibly a redefinition is required.
 
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