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Could synthetic limestone in the world's concrete market and massive kelp farms to stimulate fisheries REALLY sequester 50 GT CO2 per year, sequestering a TRILLION TONS of CO2 by 2050 and putting us back to 300ppm? That's the claim of the Foundation For Climate Restoration - PDF at link below.
https://eclipsenow.wordpress.com/2021/0 ... l-by-2050/

eclipse wrote:Could synthetic limestone in the world's concrete market and massive kelp farms to stimulate fisheries REALLY sequester 50 GT CO2 per year, sequestering a TRILLION TONS of CO2 by 2050 and putting us back to 300ppm? That's the claim of the Foundation For Climate Restoration - PDF at link below.
https://eclipsenow.wordpress.com/2021/0 ... l-by-2050/

I have no idea, but it's sure good to see such potential from ideas like that. What I DO know is:

1). The CO2 production from ordinary concrete is simply huge.
2). Barring something out of left field re technology, the need for concrete will continue to grow massively, as the global economy continues to grow massively, over time.

I still think it will take a "Star Trek" level technological drive focused on CO2 (and GHG's generally) mitigation ON TOP OF all the other efforts humanity makes to try to thread the needle on AGW mitigation and keeping society running in a way that is politically viable, for as far as the eye can see.

The problem, of course, will be how much that mitigation will COST with all the other issues vying for "fix me now" level attention from governments. (And I don't see the funding for all that GHG mitigation coming from private hands, unless it's to avoid truly draconian government penalties from excess CO2 production by corporations -- and again, there's the whole political viability issue which makes me doubt that really happens).

Outcast_Searcher wrote:

eclipse wrote:Could synthetic limestone in the world's concrete market and massive kelp farms to stimulate fisheries REALLY sequester 50 GT CO2 per year, sequestering a TRILLION TONS of CO2 by 2050 and putting us back to 300ppm? That's the claim of the Foundation For Climate Restoration - PDF at link below.
https://eclipsenow.wordpress.com/2021/0 ... l-by-2050/

I have no idea, but it's sure good to see such potential from ideas like that. What I DO know is:

1). The CO2 production from ordinary concrete is simply huge.
2). Barring something out of left field re technology, the need for concrete will continue to grow massively, as the global economy continues to grow massively, over time.

I still think it will take a "Star Trek" level technological drive focused on CO2 (and GHG's generally) mitigation ON TOP OF all the other efforts humanity makes to try to thread the needle on AGW mitigation and keeping society running in a way that is politically viable, for as far as the eye can see.

The problem, of course, will be how much that mitigation will COST with all the other issues vying for "fix me now" level attention from governments. (And I don't see the funding for all that GHG mitigation coming from private hands, unless it's to avoid truly draconian government penalties from excess CO2 production by corporations -- and again, there's the whole political viability issue which makes me doubt that really happens).

The fact many of the anti-tech campaigners leave out of the equation is the fact that over time Concrete reabsorbs much of the CO released when the limestone component of the mixture are calcined into lime. That is just how Lime works, when you roast the limestone you break loose the CO2 component and it blows away on the wind. When you then add that powdered lime to Concrete or Mortar the CaO becomes CaH2O2 and is highly chemically reactive. Any CO2 molecules in the air that bump into the wet mixture are snagged chemically to reform CaCO3 binding the material ever more solidly chemically speaking. Even after the mixture dries moisture and CO2 from the air will continue the binding process at a slower rate and concrete buried in the ground and exposed to the rainwater moving through the soil to join the water table hardens even faster. Concrete will continue to harden until such time as all free CaO molecules in the matrix have rebound CO2. CaO also reacts with sand and alumina to form Calcium Silicate CaSiO3 and Calcium Aluminate CaAlO3. Also traces of CaFeO3 and various sulfates from the addition of Calcium Sulfate (Gypsum) powder to increase work-ability during the molding and leveling processes. Ultimately Concrete absorbs less CO2 than initially given off by the lime making process however the amount it absorbs is significant and simply ignoring this chemistry to emphasize the evils of clinker manufacturing is dishonest if not deliberately deceptive.

Tanada wrote: Ultimately Concrete absorbs less CO2 than initially given off by the lime making process however the amount it absorbs is significant and simply ignoring this chemistry to emphasize the evils of clinker manufacturing is dishonest if not deliberately deceptive.

Good to know. Obviously, real world life cycle net GHG impacts should be used when evaluating the risk of using lots of modern substance X.

Unfortunately, there is plenty of statistical gamesmanship from reporting the net impacts in a credible way -- from both sides.

From the little reading I just did on it, apparently there are a variety of things that can be done to help reduce the overall carbon footprint from concrete, which sounds like good news over time.

Outcast_Searcher wrote:

Tanada wrote: Ultimately Concrete absorbs less CO2 than initially given off by the lime making process however the amount it absorbs is significant and simply ignoring this chemistry to emphasize the evils of clinker manufacturing is dishonest if not deliberately deceptive.

Good to know. Obviously, real world life cycle net GHG impacts should be used when evaluating the risk of using lots of modern substance X.

Unfortunately, there is plenty of statistical gamesmanship from reporting the net impacts in a credible way -- from both sides.

From the little reading I just did on it, apparently there are a variety of things that can be done to help reduce the overall carbon footprint from concrete, which sounds like good news over time.

A couple links you might find informative,
https://insights.globalspec.com/article/14297/carbon-injected-concrete-can-help-reduce-carbon-emissions
https://www.forconstructionpros.com/concrete/equipment-products/concrete-materials/article/21205418/strengthening-concrete-by-injecting-carbon-dioxide-c02

I remain skeptical that any attempt to reduce CO2 production or sequester CO2 is going to be large enough to make a difference.

The planet has already warmed so much that we've crossed a tipping point and utterly gigantic forest fires are burning all over the planet. AND these forest fires are now releasing huge amounts of CO2 all on their own----about 8-10 billion metric tons of CO2 per year.

That huge source of new CO2 emissions is very real and its happening right now....unlike the imaginary sequestions being projected for kelp and concrete which may or may not happen some time out in the future.

forest-fire-emissions-CO2

AND thats just the start......we've also warmed the planet to the point that we're getting huge emission of CO2 and methane from arctic Permafrost as it thaws.

Im sorry to be a such a pessimist, and I applaud the attempts to reduce anthropogenic CO2 emissions, but I think its too late to do much good, especially after Obama derailed the Copenhagen UN climate treaty and then shifted the whole UN climate treaty program from a goal of mandatory CO2 emissions to voluntary CO2 emissions......because nations aren't actually meeting even the wimpy voluntary goals they set for themselves. And now BIden and Kerry are going down the same road, so we aren't going to get a strong UN climate treaty any time soon.

Nope....IMHO its too little and too late.


Some say the world will end in fire......

Cheers!

That huge source of new CO2 emissions is very real and its happening right now....unlike the imaginary sequestions being projected for kelp and concrete which may or may not happen some time out in the future.

I hear you - global warming is serious stuff - like something from a Sci-Fi thriller these days. Don't get me started on the potential for Wet-Bulb Temperature heatwaves. (I just finished Kim Stanley Robinson's "Ministry for the future" - and that first chapter - wow!)

But here's a weird fact - and it might just be the geology of Australia being the world's largest island continent - but our megafires of 2019/2020? They released huge amounts of CO2, obviously. BUT - they also dumped heaps of smoke and dust on the oceans, and the consequent algal blooms almost soaked up as much CO2 as the fires emitted! 95%!
https://www.theguardian.com/australia-n ... hern-ocean