Eat that GW believers!

[rcain]

...The occupational exposure limit for CO2 is 5,000 ppmv averaged over a week.

..and apparently around 100,000 ppmv to kill you. ( http://biocab.org/Carbon_Dioxide_CO2.html ). nothing to worry about then.

[D Tibbets]

Well, since our Capita aren't rising all that fast and since our CO2 production per capita isn't rising at all, I guess we should just stay out of it. The US doesn't play into your scenario at all.

Global CO2 levels have been rising exponentially since at least 1832. What makes you think that's going to stop anytime soon?

I don't think that CO2 will stop rising anytime soon. I think that your 7000 ppm CO2 level in 100 years theory is STUPID and an indication that you aren't discussing this issue with ANY rationality.

Additionally, I point out that your continued insistance that the above STUPID scenario is realistic doesn't matter much to me because it doesn't involve anything that the United States would do. Since I am a citizen of the US, that is my concern. Again, your scenario is about China and India and Brazil and etc. - not about my country.

If you have a concern about CO2 levels reaching 7000 ppm, maybe you should write a letter or something. I am not sure who to write in China. Maybe you can start with an internet search. Good luck.

regards

Why I would agree that the doubling assumptions are stupid. The doubling process is not an unlimited process. with some limiting factors the level will level off at some point.
Playing with some numbers: Start with US per capita CO2 production at the greedy rate of 20 units per year. It would be difficult to increase this rate much, we are already near saturation.

http://maps.grida.no/go/graphic/nationa ... per_capita

The US population is ~300 million or ~ 1/20th of world population. Double the population over the time frame to 12 billion. This would be 40 times the current US population. Raise all of the world population to the US rate and you would have worldwide a per capita rate 40 times higher than the current US rate. This is a little less than 1/2 of what would be predicted from ~ 6.5 doublings (200 yrs/ 30 yrs doubling period). My 40X number is inflated because for simplicity, I assumed the current CO2 production outside the US was zero. A more realistic guess is that a per capita rate a little above the current Eurapean rate distributed over the world with twice the current population would be substantially less than a 20X increase. I think this would represent an upper limit on human CO2 production and to reach this would take a herculean effort on the part of all humans everywhere. Of course we would not actually be able to reach that goal, or at least not reach it for long, because we would quickly run out of carbon based fuels. We might reach that level with nuclear or truely massive solar/ wind sources, but then the carbon issue would be moot.

Dan Tibbets

[Luzr]

http://www.whoi.edu/page.do?pid=7545&ti ... 809&ct=162

“We were surprised that some organisms didn’t behave in the way we expected under elevated CO2,” said Anne L. Cohen, a research specialist at WHOI and one of the study’s co-authors. “What was really interesting was that some of the creatures, the coral, the hard clam and the lobster, for example, didn’t seem to care about CO2 until it was higher than about 1,000 parts per million [ppm].” Current atmospheric CO2 levels are about 380 ppm, she said. Above this level, calcification was reduced in the coral and the hard clam, but elevated in the lobster

So far for CO2 killing corals...

Am I surprised? Well, common sense would say that they had to live through much higher concentrations in the past, but of course, what is common sense compared to sophisticated "hide the decline" science...

[jmc]

But OK. A 1 deg C increase from doubling from 280 ppmv. We are at about 380. At 2 ppmv per year we will get there in 90 years. In 90 years the natural evolution of technology will have us off fossil fuels without crash programs and mass hysteria. Suppose the rate increases .1ppmv a year. CO2 will have doubled in about 43 years. We should be well on our way to other technologies by then.

But suppose we just keep burning at an ever increasing rate until it is all gone. It will take 103 years.

In 103 years we will have invented lots of new stuff.

It might take a lot less than 100 years...

http://www.gizmag.com/solar-panel-1-per ... ity/11143/

[seedload]

http://scienceandpublicpolicy.org/image ... candal.pdf

That

[rcain]

wow - good find! things really hotting up then.

however, whilst the list of members behind it looks pretty impressive ( http://scienceandpublicpolicy.org/personnel.html ), phrases such as :

...in short, to bring freedom, democracy, and prosperity to an instant end worldwide...'

on their front page - is just inflamatory and counterproductive (whether true or not).

if we are to get anywhere with this, it (the scientific debate at least) HAS to become depolitisized.

[TallDave]

It's really, really hard to get CO2 levels that high just burning fossil fuels anyway, because the fraction reabsorbed tends to be roughly constant. It's like pouring water into a sieve.

[alexjrgreen]

An interesting feature of the legend of Sessa and the chessboard is that the first half of the chessboard is affordable. 4,294,967,295 grains of wheat weigh about 280 tonnes, well within King Sriram's resources.

The second half of the chessboard, however, represents about a million million tonnes: almost double the world wheat harvest.

In the same way, the exponential growth of CO2 output since the industrial revolution does not yet seem a problem. Continuing the trend for another two centuries would be a different story.

Various people have quibbled figures, but in truth the figures are a sideshow. Exponential growth will exceed any threshold.

So the trend needs to stop. Saying that the US and Europe have just about stabilised their output misses the point. The Chinese and the Indians want to drive cars and the oil companies want to sell petrol to them.

It does no good to say that it doesn't matter because we will eventually run out of fossil fuels - we haven't even begun to exploit our huge methane clathrate reserves.

KitemanSA had it right. We need the Polywell to work.

[TallDave]

It does no good to say that it doesn't matter because we will eventually run out of fossil fuels - we haven't even begun to exploit our huge methane clathrate reserves.

It's actually less than the fossil fuel reserves.

http://en.wikipedia.org/wiki/Methane_clathrate

Recent estimates constrained by direct sampling suggest the global inventory lies between 1 × 1015 and 5 × 1015 cubic metres (1 quadrillion to 5 quadrillion).[15] This estimate, corresponding to 500-2500 gigatonnes carbon (Gt C), is smaller than the 5000 Gt C estimated for all other fossil fuel reserves but substantially larger than the ~230 Gt C estimated for other natural gas sources
...
For comparison the total carbon in the atmosphere is around 700 gigatons

So, if 380ppm = 700 GT, then 5000 ppm = 9200GT. Take 700 + 5000 (fossil fuels) + 2500 (best case methane clathrates) = 8200 GT. Getting close!

But of course you can't get all that carbon into the atmosphere, because the carbon cycle is sucking a constant fraction back out every year, and some carbon fuel depots are more expensive to exploit than others. I expect they would top out below 2000 PPM before it stopped being feasible.

http://en.wikipedia.org/wiki/Carbon_cycle

[alexjrgreen]

But of course you can't get all that carbon into the atmosphere, because the carbon cycle is sucking a constant fraction back out every year, and some carbon fuel depots are more expensive to exploit than others.

World CO2 levels have been growing exponentially since at least 1832, nonetheless.

I expect they would top out below 2000 PPM before it stopped being economically feasible.

All such predictions have proved unfounded in the past.

[TallDave]

World CO2 levels have been growing exponentially since at least 1832, nonetheless.

Doesn't matter, there isn't enough carbon fuel to keep that going to 5000ppm. Anyways, they've only gone from 280 to 380. Extrapolating to 5000 is, shall we say, highly speculative.

I expect they would top out below 2000 PPM before it stopped being economically feasible.

All such predictions have proved unfounded in the past.

There haven't been any predictions on where CO2 PPM would top out in the past, afaik. Until recently, total reserves was guesswork and CO2 wasn't high on the list of concerns.

[seedload]

This whole business just gets worse. Google just took "climategate" out of its list of suggestions. Go to google and start typing "climategate" and you won't see an autocomplete suggestion for climategate. But they missed "climate-gate" which is still in there.

If "climate-gate" is there but "climategate" is not, there is no doubt that climategate was taken out intentionally.

Who is on the board of Google? Al Gore.

[TallDave]

Really? I thought they fixed the climategate thing. Did they unfix it again?

So much for "Don't be evil." I guess now it's "Punish the evildoers!"

[Luzr]

But of course you can't get all that carbon into the atmosphere, because the carbon cycle is sucking a constant fraction back out every year, and some carbon fuel depots are more expensive to exploit than others.

World CO2 levels have been growing exponentially since at least 1832, nonetheless.

Human emissions maybe. Levels seem to follow linear pattern.

Two more points:

a) Solid CO2 measurements started in 1960.
b) If they would have been growing since 1832, it would imply that they are mostly of natural sources (because there was not much fossil fuels burned at those times).

I expect they would top out below 2000 PPM before it stopped being economically feasible.

All such predictions have proved unfounded in the past.

So we do not have to worry about fossil fuel shortage? Well, that is a good news, thanks!

[alexjrgreen]

Human emissions maybe. Levels seem to follow linear pattern.

Hardly. Historical trends in carbon dioxide concentrations and temperature, on a geological and recent time scale.

Two more points:

a) Solid CO2 measurements started in 1960.

Older figures are from analysis of the Law Dome DE08, DE08-2, and DSS ice cores.

b) If they would have been growing since 1832, it would imply that they are mostly of natural sources (because there was not much fossil fuels burned at those times).

The industrial revolution started small. That's why the growth is exponential and not linear.