On Anthony Watts' influential blog, Eric Worrall proposes to brand a "perfect U-turn" inwards the carbon dioxide policy:
Let's Cook Limestone to Raise Atmospheric CO2 to 1,000ppmHe claims that yesteryear heating limestone, the publish energy nosotros postulate to eat would cost only $100 billion in addition to perchance $300 billion alongside additional expenses. Because at that spot is a missing component of 3 inwards the calculation of the majority of CO2 inwards the atmosphere, a to a greater extent than realistic toll would move $1 trillion.
Limestone blocks inwards Malta. To arrive to a greater extent than confusing, "malta" agency mortar (the stuff to mucilage bricks) inwards Czech.
I would nonetheless unwrap it extremely inexpensive because the benefits would move immense. But is the calculation right?
The electrical current CO2 concentration inwards the air is 400 ppm. 1,000 ppm would move 2.5 times higher. Take a foursquare source of that in addition to y'all instruct a adept gauge of the improvements of the agricultural yields. They would boundary yesteryear a component of 1.5 or then i.e. yesteryear 50 percent. Because agriculture produces some 4% of the global gross domestic product now, or over 3 trillion dollars, the investment of $1 trillion could move returned inwards iv months or so.
Imagine the happy Africans alongside lots of nutrient etc.
OK, what is the algorithm to instruct to this quasi-paradise? Worrall tells us to direct hold limestone (Czech: vápenec) in addition to rut it. The reaction is\[
{\rm CaCO}_3 + {\rm heat} \to {\rm CaO} + {\rm CO}_2.
\] The production CaO is quicklime (Czech: nehašené vápno). Burning of 1 kilogram of limestone produces\[
\frac{12+16+16}{40+12+16+16+16} = \frac{44}{100} = 0.44
\] kilograms of CO2. The inverse of this ratio is 2.3. How much carbon dioxide nosotros need? The electrical current majority of this gas inwards the atmosphere is some 3,000 gigatons. Worrall got a final result smaller yesteryear a component of 3 because he didn't appreciate that "ppm" refers to "ppmv", parts per meg of the volume, in addition to he in all likelihood made other mistakes, too.
OK, 3,000 gigatons is 400 ppm. We postulate to add together 600 ppm then nosotros postulate to add together some 4,500 gigatons. Multiply it yesteryear the component of 2.3 mentioned higher upward in addition to y'all instruct 10,350 gigatons of limestone that y'all postulate to rut up. Worrall points out that y'all exclusively postulate 3.6 MJ/kg to instruct the carbon dioxide from the limestone. We postulate to practise that alongside \(10.35\times 10^{15}\,{\rm kg}\) of limestone, as I mentioned, then y'all postulate \(37\times 10^{15}\) megajoules of energy. Or \(3.7\times 10^{22}\,{\rm J}\).
If y'all listen the automobile horn piece you're shopping, it's in all likelihood because your puppies are already losing patience alongside you.
Because 1 hr is 3,600 seconds, \(37\times 10^{15}\) megajoules is virtually \(10\times 10^{12}\) megawatthours. One megawatthour may move produced for $30 then it costs $300 trillion (one trillion is 10 to the 12th power). Worrall announced $100 billion only. So I am sorry, he was as good optimistic yesteryear a component of 3,000.
It is to a greater extent than expensive than he thinks to dramatically increment the CO2. I previously said that agriculture produces some $3 trillion per twelvemonth then fifty-fifty if y'all fail the fact that its greater output would lower the nutrient prices, the expenses of $300 trillion would exclusively move repaid inwards 100 years.
Moreover, y'all would postulate to maintain on heating additional limestone to maintain the CO2 high. Right now, nosotros are emitting the equivalent of iv ppm of CO2 every year. About ii ppm of it is absorbed yesteryear Mother Nature – the remaining ii ppm is the observed increment of the CO2 concentration every year.
I think that the absorption yesteryear Nature (oceans in addition to biosphere) is about proportional to the excess of CO2 higher upward the equilibrium value of 280 ppm. Right now, the excess is 400-280 = 120 ppm. At 1,000 ppm, it would move 720 ppm, i.e. vi times higher than now. So without whatever CO2 emissions, Nature would move reducing the CO2 concentration yesteryear some 12 ppm every year.
So inwards 1 century, y'all would postulate to rut additional limestone equivalent to 1200 ppm of extra CO2. That's ii times higher than the 600 ppm increment nosotros fabricated before. So inwards a century, the total expenses would move higher yesteryear some other component of 3. So to pick out CO2 to 1,000 ppm inwards this fashion in addition to maintain it at that spot for a century would require some $1,000 trillion or a quadrillion dollars, over 1 decade of the public GDP.
At this level, I experience that the proposed solution is no longer economic. Once y'all know this final result – alongside my railroad train of the component of 3,000 – y'all mightiness state that it should direct hold been obvious that the global re-engineering of the whole atmosphere won't move economic. The atmosphere is only as good large. Efforts to increment the concentration inwards the whole atmosphere are the reverse projection to the plans to trim the carbon dioxide – but inwards absolute value, it's pretty much every bit stupid. At least, Worrall got the right sign, different the IPCC types.
But I practise believe that at that spot are to a greater extent than focused or regional or local projects that would brand sense. I believe that for vastly lower amounts of money, much of Sahara could move made fertile. Bring H2O over there, practise large greenhouses, restore a large lake over there, in addition to then on. The wealthy nations should think virtually such projects these days because it's plausible that publish energy volition proceed to move rather inexpensive for quite some time.
By the way, there's a to a greater extent than obvious fashion to instruct the CO2. Just burn downwardly the fossil fuels. Coal is inexpensive but arguably as good muddied (or it's as good difficult to withdraw the existent pollutants). And stone oil production can't move increased as good much in addition to most of it is already burned, anyway. ;-) But it's nonetheless interesting to know how much the carbon dioxide would cost if y'all only got it from burning oil.
One barrel of stone oil produces some 0.3 tons of carbon dioxide when it burns. We needed to add together 4,500 gigatons of CO2, if y'all remember, then nosotros postulate 4,500/0.3 = 15,000 gigabarrels (billions of barrels) – without the tripling for the "preservation" of the elevated concentration. At the toll $50 per barrel, it is 15,000 times billion times $50 = $750 trillion dollars. For the same problem, nosotros got $300 trillion using limestone. So limestone is indeed yesteryear a component of 2.5 cheaper than only burning oil. It's in all likelihood cheaper than burning stone oil but non spectacularly cheaper.
If y'all think that y'all tin unwrap a method to increment CO2 to 1,000 ppm for a toll much lower than "hundreds of trillions of dollars", I am certainly interested.