It partly depends on whether you include water vapor, albedo, and other similar feedbacks. If you include water vapor (not counting it as part of the percentage of the atmosphere, as is often done, since it varies so much), and artificially hold all other feedbacks the same, then... to ballpark it...
You'd have approximately 3-4C from each doubling of CO2. Since there may be saturation effects when you get so far out of our current range, let's go with 3C. Also, for mathematical convenience, let's count the current concentration as .05%. I believe the current average temperature of the Earth is about 15C (it doesn't change much year round, since summer in the northern hemisphere is winter in the southern, and vice versa)
Count how many doublings it takes to get from .05% to 100%. Multiply that by 3, then add it to 15. That's the Earth's new average temperature (you'll have to do it yourself, it's late and I can't math).
If you're not including water vapor, but artificially preserving albedo feedbacks and the like... I think you'd need to subtract about ... if I recall correctly, the greenhouse effect adds about 15C to the average temperature, and about 1/2 of that is from water vapor. So subtract 8C to start with. Then, multiply the number of doublings by... I believe it's 2C without the feedbacks. Possibly only 1.
I'd check all those numbers with someone that's not up 2 hours past her bedtime, however. But that's the basic procedure you'd use.
Mars has nearly that type of climate. Very little water, but a lot of CO2. So much CO2 that the poles have dry ice covering them.
Chem flunky's answer is off. First, she assumes 3-4 degree for a doubling of CO2 with water vapor, which is assuming that the positive feedbacks are much greater than the negative feedbacks. That has not been proven true, only speculated. Speculated with models that have consistently overestimated the warming. Second CO2 doubling does not even add 1 degree.
Now given that 100% would inherently imply no H2O and no methane. The temp increase caused by greenhouse gasses are 33 degrees, not 14. Of this, CO2 contributes about 10% or about 4 degrees. If CO2 was 100% of the atmosphere, that would represent about 11 doublings or at most an 11 degree increase from it already 4 degree contribution. So the temp of the earth would be about 18 degrees less than it currently is. This is assuming that saturation of the wavelengths does not occur. So my guestimate is that it would be between 18-24 degrees colder than it currently is.
Note that others place the CO2 contribution at 20%, which when factored would change my estimate to 14-20 degrees colder. Also the current CO2 concentration os 0.04%, not 0.05%.
Edit:
Using another assumption of say CO2 replacing all of the nitrogen in the atmosphere, you'd have about the same number of doublings (~10.5) with no loss to the contributions from H2O and other GHGs. This would be about a 10.5 degree increase.
Now the IPCC has the upper limits of its models at 11 degrees, mostly because they like to scare people with absrud predictions that will never comes true. Literally they have to assume 2 doubling from 400 ppm to 1600 ppm. Note that ALL of the CO2 we have placed into the atmosphere since the start of the industrial age amounts to 100 ppm, so this represents 12 times the amount of CO2. Then you have to assume positive feedbacks to the tune of 4.5 times the amount added to what CO2 can do alone.
And to show you just how little EVEN THE WARMERS believe this crap, realize that this is extremely exponential. The warmers come here trying to justify that an increase in temps occurred over the last 60 years by using LINEAR regression. LINEAR!!! They have so little confidence in their exponential models that they use linear regression???
And the difference??? The IPCC reports 2-11 degrees of change in the next 100 years. Linear regression would give 1.0-1.3, THE SAME LINEAR THEY USE TO SHOW WARMING IS OCCURRING!!!!
I am guessing net temperature difference would be lower than now. As many other gases in the atmosphere have higher GHG potential than CO2 does.
Life would not exist. So we would never know.
http://answers.yahoo.com/question/index;...
I love how the science minds are answering this question seriously. Life needs oxygen and to be real honest it would be nearly impossible for that to happen. There would have to be a massive catastrophe that killed all plant life. Perhaps if the sun died. This question has no answer really. If I had to guess it would be freezing cold, absolute zero. The sun would create plant life to assist photosynthesis......there would have to be no sun. IMO this is because earth is capable of supporting life with the sun and moon.
well, dry ice would be really cheap, but since everyone already has all they could be, they'd pass on that deal anyway. I bet seven-up would catch up to coke and pepsi. So I'll say o=c=o overthrows the number system and his best girlfriend decides how hot it is. Then we can start over withthe pyramids. ice is Ice, Homer.
Billy good answer but what was the point of that link?
Their will be no oxygen. So their will be no life. No plants no animals no trees . NO HUMANS. So the themperature will be high. I guess so.
It would be hot enough to melt lead. It would rain carbolic acid and the GOP/Tea/Fox/Jesus freak party would blame the none existent 'liberals'.
About 9C warmer given that a doubling for CO2 is 3.7M2 about 1C
If Earths 1 bar atmosphere was 100% CO2 what would the temperature be?
