Global warming thought experiment?

Question

Okay, so we're going to design a box to neutralize the atmospheric effects of global warming. Let's assume that all current pollution, exhaust, etc. continues at the same rate...that we can't get anybody to change anything about what they are doing to hurt the atmosphere, but it doesn't get any worse.

1. What would the inputs to the box be? (What substances should the box take in?) (Amounts, if you can.)
2. What would the output from the box be?
(What substances should the box emit?)
3. Assuming our box works almost instantly, returning our atmosphere to the condition it was in before we started messing with it, and neutralizing the current level of pollution, how long would it take before we saw the effects of what we did, and saw climate patterns return to normal?
4. If you think we need more than one box with different processes, please state.
5. If you don't think there is a problem with global warming, go back to the kitchen, get another beer, and chill for a while.

Make that "neutralize the atmospheric effects causing global warming"

Uh huh..those aliens have a lot to answer for....not the least of which is all those Grade B movies...

"Transmogrification" sounds painful. OK, so we can' t pull the knife out too quickly... In reality, though, we can't fix the problem overnight either, though, so let's ignore our adapting species for the sake of the experiment, and maybe we'd better go all the way back to avoid all that coal powered nastiness... wear a jacket or something.

PS Recent data has eliminated indigestion as a possible cause.

Oops "data have eliminated"

From the IPCC report:The concentration of atmospheric CO2 has increased from a pre-industrial value of about 280 ppm to 379 ppm in 2005. Atmospheric CO2 concentration increased by only 20 ppm over the 8000 years prior to industrialisation; multi-decadal to centennial-scale variations were less than 10 ppm and likely due mostly to natural processes. However, since 1750, the CO2 concentration has risen by nearly 100 ppm. The annual CO2 growth rate was larger during the last
10 years (1995–2005 average: 1.9 ppm yr–1) than it has been since continuous direct atmospheric measurements began (1960–2005 average: 1.4 ppm yr–1). {2.3, 6.4, 6.5}
So, for instance, does our box have to "eat" 100 ppm of CO2? How much CO2 is that?

Thanks to everyone who has contributed so far. I'm still a bit uncertain about some points, though. First, I thought part of the problem is that the "system" had been disturbed. For instance, a lot of ice (glacier, small ice cap, snow cover, sea ice) has melted, and the to the extent this contributed to the maintenence of the system, this maintaining effect is gone. This wouldn't be restored by just removing just, say, 50 ppm of CO2, would it? We would have to find a new balance point, wouldn't we?

Also, a math question: how does one go from the concentration of CO2 to the amount of CO2? How much CO2 is 100ppm?

Jake - earlier data comes from ice cores, which seem to be fairly reliable in showing the concentration of gasses.
http://en.wikipedia.org/wiki/Ice_core

Answer 1

Our box doesn't have to eat 100ppm of atmospheric CO2 because we're still okay at our current temperature. The WHO estimates that 150,000 deaths/year can be attributed to global warming, so perhaps we'd be better off at 280ppm of atmospheric CO2, but let's just assume that our current global temperature is acceptable.

The problem is that humans are emitting more CO2 than the natural carbon cycle can absorb. The following page describes the process with numbers:

http://www.metoffice.gov.uk/research/hadleycentre/models/carbon_cycle/intro_global.html

Basically the natural cycle absorbs about 2 billion tons more than it emits. However, humans emit about 5.5 billion tons of carbon each year, so we make up for this gap and then some. So in order not to increase the atmospheric CO2 levels any further, we would need your box to collect at least 3.5 billion tons of carbon each year.

1) Inputs would be greenhouse gases, mainly CO2. Roughly 3.5 billion tons of CO2 each year.

2) Outputs wouldn't be necessary.

3) If we neutralize our extra emissions in this fashion, we would still see roughly a 1-2°C average global temperature increase over the next few decades due to the carbon which has already been emitted, but then it would stabilize.

http://green.yahoo.com/index.php?q=node/681

4) The one box is sufficient as long as it collects other greenhouse gases besides CO2 (such as methane). It might be good if it also absorbed some of the existing atmospheric CO2.

Answer 2

We would need at least two "boxes"

One will be the "quick fix" boxes which pump extra heat into the upper atmosphere. the air temperature drops 10 degrees every KM. Pumping seawater up a tether to a helium balloon would reduce the excess heat buildup in the ocean.

The other "box" would be the carbon "box". we would need to cut down trees, make charcoal, and then store the charcoal.

A greenhouse can grow out the trees until they are 2 years old, before they are transfered to open air. Then they can be planted at a proper spacing for 20 year's growth. If this is done on a one square mile area, that 640 acres, so, 32 acres of trees would be harvested and replanted each year.

in typical charcoal production, much carbon is lost because wood is burned to heat the wood which is charred. A process which heats the charcoal with assistance from soalr power could produce more charcoal per pound of wood used than conventional kilns.

Once the charcoal is produced, it can be compressed and stored.

The carbon boxes will use HUGE amounts of land. That's why we will need the quick-fix boxes. The carbon boxes will take time, and meanwhile, we must prevent the ice and snow from melting. Ice reflects more light than rock, so, melting glaciers are a positive feedback. less ice = more heat = less ice ad nasuseum.

Both would be enormously expensive, but the seawater pumps would reduce the number of excess hurricanes, so, would save the US billions of dollars in hurricane damage.

Answer 3

150 years ago, global temperature was 0.8 C lower than today. Do you want to go all the way back, or just part way? Back then, folks could walk across New York Harbor to Manhattan Island because it would freeze. I need to know because I have my tools out and ready to go, just need to have those specs.

The plan is for a quantum-field space-time continuum transmogrification pump. We will locate the parallel quantum reality in which Hitler and the Axis powers won WWII and pump all of our waste products into their world, mucking it up further than it probably already is.

You need to hurry, though. There's the distinct possibility that someone else in an alternate reality has already created this pump and THAT is what has set us off balance!

All kidding aside, we do have to consider just how or if we remove the "offending" gases, and just how fast we would do it. The Earth is in a constant state of adjustment to all environmental conditions, including "artificially" created ones. We can mess things up further by non-judicious actions to "counteract" our destructive actions. For example, photosynthetic organisms (phytoplankton, plants) are currently adjusting to increased levels of CO2 as well as increased temperatures, this includes adapting the types of chlorophyll and photosynthetic pathways, the dominance of certain species ans strains more suitable to the changing environment, etc. Making drastic changes will negatively affect the natural processes, possibly resulting in increased death or disease of these organisms.

An analogy: if you are accidentally stabbed in the chest with an 8 inch kitchen knife, you SHOULD NOT try to remove it. A surgeon will run the proper tests, take the proper precautions, and remove it with the utmost care only after thorough pre-planning.

I'm not even sure we've been stabbed, yet. That chest pain could just be indigestion...

Answer 4

If you instantly change the chemical abundances in the atmosphere to pre-industrial times, temperatures would change back fairly quickly: within a decade. Most of the residual heat is in the oceans. The atmosphere can give up its heat in a matter of hours.

It might be more optimal just to leave the current levels of atmospheric gasses----the world-wide climate is pretty good right now. If you could absorb all future human greenhouse gasses, and release nothing, that may save the world from a mass extinction.

Answer 5

A mole of an ideal gas always equals 22.4 liters at STPD. Since a mole also equals 6.02 X10 to the 23rd power, you should be able to apply your ppm to that and then work back to volume. I'm too lazy to do it for you.

Answer 6

They didn't know about CO2 in 1750. Nice try..they didn't have the technology to keep records back then

Answer 7

we're not causing global warming...the aliens are warming our climate to a preferred temperature so that they can harvest us for food.