The theoretical maximum CO2 we could have added to the atmosphere is 100 ppmv of the 400 ppmV currently in the atmosphere. It seems to me that alarmists who are challenged in both math and science like to pretend we doubled it already and raised the temperature by a whopping 1 degree C. In fact to double the first time, we would presumably have to emit at least 3 times as much as we have (to go from 300 to 600 ppmv). To double it again again, we would have to emit over 6 times that amount and that isn't taking into account the fact that increased CO2 would cause increased absorption into the ocean as well as other so called carbon sinks. Not only do we have diminishing returns on the increase in heat from CO2, we have diminishing returns on the grey matter in Alarmists thick skulls. Actual science is something they don't like. They only like that which protects their cult.
I should also put out the limitation that CO2 concentrations in atmosphere are based solely on ice core proxies that have limitations. When you use plant stomata proxies, CO2 levels are much more variable and that is why alarmists ignore plant stomata data. I should also point out the limitation that there are other things that control temperature and there may be things that buffer temperature so pretending they know an increase of CO2 would have "this effect" or "that effect" is ludicrous.
It's true that the ability of CO2 to cause warming diminishes as CO2 levels increase.
Since we are now at about 400ppm CO2 level, it really doesn't matter very much how much more CO2 increases as far as it's ability to hold more heat in the atmosphere. The effect of CO2 doubling from it's current 400ppm to say --- 800ppm would be very small.
It's the first 20ppm of CO2 that has most of CO2's affect on Warming.
This is because their is only so much infrared radiation to be absorbed. Increasing CO2 does not increase the amount of infrared available to be absorbed.
An analogy might be, if I pour a shot-glass of water onto a counter top and use a paper towel to pick it up, the first paper towel would get maybe half of it. The next paper towel might get nearly all the rest, the third would finish the job. And it doesn't matter how many more paper towels I use after that, there simply is no more water to be absorbed, so it's to no effect.
Another analogy would be if you wanted to stop sunlight from streaming through a window. Put a coat of black paint on the window and you've probably stopped more than 90% of the light coming through. Put on another coat and you've stopped more than 99% --- addition coats of paint will have almost no effect.
There is ONLY SO MUCH infrared energy available to be absorbed and at our current level of 400ppm there is almost none available for increased CO2 to absorb --- no matter how much CO2 you add to the air.
This Graph illustrates the point fairly well, from the same page you linked:
http://wattsupwiththat.files.wordpress.com/2010/03/heating_effect_of_co2.png
the logarithmic dependency means you get approximately the same effect for every doubling of CO2. That doesn't mean that additional CO2 will have little effect on temperature, it means that more CO2 is required to achieve a doubling. We are emitting enough CO2 to accomplish that doubling within the century.
Jeff Engr's answer is amusing:
"Those who have answered you so far must have very little scientific knowledge on this subject. "
...
"It is also a scientific FACT that the ability of CO2 to perform as a GHG based on a concentration of CO2 in the atmosphere follows a degrading algorithmic curve."
Jeff Engr must have taken some advanced science classes to learn about those "degrading algorithmic curves."
Those who have answered you so far must have very little scientific knowledge on this subject.
It is a scientific FACT that the ability of CO2 to perform as a green house gas has limits. ALL things in nature have limits.
It is a scientific FACT that we have measured and cataloged the known properties of CO2 to perform at a GHG.
It is also a scientific FACT that the ability of CO2 to perform as a GHG based on a concentration of CO2 in the atmosphere follows a degrading algorithmic curve. 90% or more of CO2's ability to perform as a GHG resides in the first 100ppm. We are now at 400 ppm. The known physical ability of CO2 to increase the rate of warming with increased concentrations in the air is all but exhausted. If we double to 800 ppm our instruments will barely register the difference that the doubling of CO2 in our atmosphere would make.
At 20 ppm CO2 helps acts as a GHG with a 2 degree centigrade increase
At 280 ppm CO2 drives acts as a GHG with a total impact of 3.5 degree centigrade increase
At 380 ppm CO2 drives acts as a GHG with a total impact of 3.6 degree centigrade increase
At 600 ppm CO2 drives acts as a GHG with a total impact of 3.8 degree centigrade increase
AGW is not based on the evil of CO2. AGW is based on a cascade effect. i.e once we reach this "tipping point" other natural phenomenon will take precedence and drive accelerated warming. i.e. permafrost's with start releasing large volumes of natural gas (another potent GHG) etc. However new empirical data sets demonstrate that this is NOT the case...(for permafrost's anyway)
AGW alarmists who do not acknowledge this are merely political mouthpieces with little to no scientific education. Either that or they are openly lying to you. Not sure which would make you feel better...
Jeff Engr is mistaken. For each doubling of CO2 there is a 1C temperature increase. this means that a doubling from 10ppm to 20ppm causes a 1C temperature increase. 50ppm to 100ppm causes a 1C temperature increase. a doubling from 280ppm to 560ppm and a doubling from 400ppm to 800ppm both cause the same temperature rise. As you can see, it takes more CO2 to cause the same temperature increase. However this does not mean, as he states, "If we double to 800 ppm our instruments will barely register the difference that the doubling of CO2 in our atmosphere would make."
JZ: You have no idea what you are talking about do you? For each doubling it increase the temperature by 1C without any feedbacks. This is commonly accepted both among skeptics and realists. It is the feedbacks that are called into question. One wonders why you misunderstand this basic concept.
https://workspace.imperial.ac.uk/physics...
http://proceedings.spiedigitallibrary.or...
You are ignoring reality.
<>
It is a claim, not science.
In denier-world, any claim posted on a blog is per definition 'science', no matter how outrageous (and there's plenty of examples of just that) the claim is.
Just ask yourself this as a skeptic: if David Archibald is so sure about his claim, then why does he not publish a peer-reviewed paper about it? Why does he instead resort to a blog post on World's Number 1 denier blog?
If were going to take for granted whatever a blog-post claims, then 9/11 was an inside job, aliens landed in Roswell and there are lizard people living in a hollow moon.
I read http://wattsupwiththat.com/2010/03/08/the-logarithmic-effect-of-carbon-dioxide/ which claims that increases in CO2 levels logarithmically increase temperature. Because the current levels are so high, this would mean that additional CO2 would have very little effect on temperature. Can you please provide additional sources to back this claim or to debunk this claim?
the logarithmic dependency means you get approximately the same effect for every doubling of CO2. That doesn't mean that additional CO2 will have little effect on temperature, it means that more CO2 is required to achieve a doubling. We are emitting enough CO2 to accomplish that doubling within the century.
Jeff Engr's answer is amusing:
"Those who have answered you so far must have very little scientific knowledge on this subject. "
...
"It is also a scientific FACT that the ability of CO2 to perform as a GHG based on a concentration of CO2 in the atmosphere follows a degrading algorithmic curve."
Jeff Engr must have taken some advanced science classes to learn about those "degrading algorithmic curves."
Those who have answered you so far must have very little scientific knowledge on this subject.
It is a scientific FACT that the ability of CO2 to perform as a green house gas has limits. ALL things in nature have limits.
It is a scientific FACT that we have measured and cataloged the known properties of CO2 to perform at a GHG.
It is also a scientific FACT that the ability of CO2 to perform as a GHG based on a concentration of CO2 in the atmosphere follows a degrading algorithmic curve. 90% or more of CO2's ability to perform as a GHG resides in the first 100ppm. We are now at 400 ppm. The known physical ability of CO2 to increase the rate of warming with increased concentrations in the air is all but exhausted. If we double to 800 ppm our instruments will barely register the difference that the doubling of CO2 in our atmosphere would make.
At 20 ppm CO2 helps acts as a GHG with a 2 degree centigrade increase
At 280 ppm CO2 drives acts as a GHG with a total impact of 3.5 degree centigrade increase
At 380 ppm CO2 drives acts as a GHG with a total impact of 3.6 degree centigrade increase
At 600 ppm CO2 drives acts as a GHG with a total impact of 3.8 degree centigrade increase
AGW is not based on the evil of CO2. AGW is based on a cascade effect. i.e once we reach this "tipping point" other natural phenomenon will take precedence and drive accelerated warming. i.e. permafrost's with start releasing large volumes of natural gas (another potent GHG) etc. However new empirical data sets demonstrate that this is NOT the case...(for permafrost's anyway)
AGW alarmists who do not acknowledge this are merely political mouthpieces with little to no scientific education. Either that or they are openly lying to you. Not sure which would make you feel better...
Jeff Engr is mistaken. For each doubling of CO2 there is a 1C temperature increase. this means that a doubling from 10ppm to 20ppm causes a 1C temperature increase. 50ppm to 100ppm causes a 1C temperature increase. a doubling from 280ppm to 560ppm and a doubling from 400ppm to 800ppm both cause the same temperature rise. As you can see, it takes more CO2 to cause the same temperature increase. However this does not mean, as he states, "If we double to 800 ppm our instruments will barely register the difference that the doubling of CO2 in our atmosphere would make."
JZ: You have no idea what you are talking about do you? For each doubling it increase the temperature by 1C without any feedbacks. This is commonly accepted both among skeptics and realists. It is the feedbacks that are called into question. One wonders why you misunderstand this basic concept.
https://workspace.imperial.ac.uk/physics...
http://proceedings.spiedigitallibrary.or...
You are ignoring reality.
<
It is a claim, not science.
In denier-world, any claim posted on a blog is per definition 'science', no matter how outrageous (and there's plenty of examples of just that) the claim is.
Just ask yourself this as a skeptic: if David Archibald is so sure about his claim, then why does he not publish a peer-reviewed paper about it? Why does he instead resort to a blog post on World's Number 1 denier blog?
If were going to take for granted whatever a blog-post claims, then 9/11 was an inside job, aliens landed in Roswell and there are lizard people living in a hollow moon.
I read http://wattsupwiththat.com/2010/03/08/the-logarithmic-effect-of-carbon-dioxide/ which claims that increases in CO2 levels logarithmically increase temperature. Because the current levels are so high, this would mean that additional CO2 would have very little effect on temperature. Can you please provide additional sources to back this claim or to debunk this claim?
