Arctic Sea Ice : Forum

AGW in general => Policy and solutions => Topic started by: jai mitchell on November 26, 2018, 07:28:56 PM

Title: Direct Air Capture (of Carbon Dioxide)
Post by: jai mitchell on November 26, 2018, 07:28:56 PM
Surprised this thread doesn't yet exist since it will be absolutely necessary to remove between 800 and 1,000 Giga-tonnes of Carbon from the Earth's atmosphere by 2100.  This, largely due to the shift of land, southern oceans, tropic peats and boreal systems into carbon sources. (this process is starting already)

so lets continue to post new developments regarding the process of direct air capture of carbon dioxide.  This is through agriculture, ocean nutrient seeding, reforestation/preservation and industrial activity.  Maybe we will find others too along the way.

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: jai mitchell on November 26, 2018, 07:30:32 PM
This new paper shows a highly efficient method to convert soluble carbon dioxide (in water) to plastics.

https://www.sciencealert.com/scientists-have-figured-out-a-way-to-convert-carbon-dioxide-into-plastic

Quote
Researchers have developed catalysts that can convert carbon dioxide—the main cause of global warming—into plastics, fabrics, resins, and other products.

The electrocatalysts are the first materials, aside from enzymes, that can turn carbon dioxide and water into carbon building blocks containing one, two, three, or four carbon atoms with more than 99 percent efficiency.

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: crandles on November 26, 2018, 07:32:30 PM
This has been posted on CCS thread

Does anyone have any comments on this?

https://www.technologyreview.com/s/540706/researcher-demonstrates-how-to-suck-carbon-from-the-air-make-stuff-from-it/

I'm hearing it touted as a way to reduce CO2 to preindustrial levels in 10 years (admittedly with very extensive deployment!), but there seems to be little information on how the atmospheric capture actually works... and whether there's enough lithium to do it on that scale in the first place! Call me a sceptic, but to have no news after two and a half years...

Any further info on this process?

There's a later, and highly detailed article in Nature:
Tracking airborne CO2 mitigation and low cost transformation into valuable carbon nanotubes
https://www.nature.com/articles/srep27760 (https://www.nature.com/articles/srep27760)
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: jai mitchell on November 26, 2018, 08:07:36 PM
cran,

thanks but those are not talking about the technology I posted about.

carbon capture and storage (CCS) refers to high-temperature capture of carbon from fossil fuel or industrial fossil fuel energy exhaust.

this is a thread for the kinds of links crandles posted about Direct Air Capture (DAC) of carbon dioxide.

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on November 27, 2018, 05:44:33 PM
There are so many studies going on in this field, that it's difficult to track them all.  Here is a study of the studies (from 2017):

http://iopscience.iop.org/article/10.1088/1748-9326/aa5ee5/meta (http://iopscience.iop.org/article/10.1088/1748-9326/aa5ee5/meta)

Excerpt from the abstract (emphasis added):

Quote
Despite being a relatively young topic, negative emission technologies (NETs) have attracted growing attention in climate change research over the last decade. A sizeable body of evidence on NETs has accumulated across different fields that is by today too large and too diverse to be comprehensively tracked by individuals. Yet, understanding the size, composition and thematic structure of this literature corpus is a crucial pre-condition for effective scientific assessments of NETs as, for example, required for the new special report on the 1.5 °C by the Intergovernmental Panel on Climate Change (IPCC). In this paper we use scientometric methods and topic modelling to identify and characterize the available evidence on NETs as recorded in the Web of Science. We find that the development of the literature on NETs has started later than for climate change as a whole, but proceeds more quickly by now. A total number of about 2900 studies have accumulated between 1991 and 2016 with almost 500 new publications in 2016.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on February 14, 2019, 12:58:33 AM
A breakthrough in artificial leaf technology that allows the artificial leaf to operate at normal atmospheric pressures has been announced:

https://www.sciencedaily.com/releases/2019/02/190212160020.htm (https://www.sciencedaily.com/releases/2019/02/190212160020.htm)

Quote
Singh and his colleague Aditya Prajapati, a graduate student in his lab, proposed solving this problem by encapsulating a traditional artificial leaf inside a transparent capsule made of a semi-permeable membrane of quaternary ammonium resin and filled with water. The membrane allows water from inside to evaporate out when warmed by sunlight. As water passes out through the membrane, it selectively pulls in carbon dioxide from the air. The artificial photosynthetic unit inside the capsule is made up of a light absorber coated with catalysts that convert the carbon dioxide to carbon monoxide, which can be siphoned off and used as a basis for the creation of various synthetic fuels. Oxygen is also produced and can either be collected or released into the surrounding environment.

"By enveloping traditional artificial leaf technology inside this specialized membrane, the whole unit is able to function outside, like a natural leaf," Singh said.

According to their calculations, 360 leaves, each 1.7 meters long and 0.2 meters wide, would produce close to a half-ton of carbon monoxide per day that could be used as the basis for synthetic fuels. Three hundred and sixty of these artificial leaves covering a 500-meter square area would be able to reduce carbon dioxide levels by 10 percent in the surrounding air within 100 meters of the array in one day.

"Our conceptual design uses readily available materials and technology, that when combined can produce an artificial leaf that is ready to be deployed outside the lab where it can play a significant role in reducing greenhouse gases in the atmosphere," Singh said.

Once you get the carbon dioxide converted to carbon monoxide, it opens up a lot of possible uses as fuels:

https://phys.org/news/2018-03-co2-usable-energy.html (https://phys.org/news/2018-03-co2-usable-energy.html)

Quote
"There are many ways to use CO," said Eli Stavitski, a scientist at Brookhaven and an author on the paper. "You can react it with water to produce energy-rich hydrogen gas, or with hydrogen to produce useful chemicals, such as hydrocarbons or alcohols. If there were a sustainable, cost-efficient route to transform CO2 to CO, it would benefit society greatly."
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on March 01, 2019, 06:39:25 PM
Once carbon dioxide is captured, it will need to be stored in a way it can't escape back into the atmosphere.  Researchers have just announced a new method for turning CO2 into a solid:

https://www.technologynetworks.com/tn/news/turning-carbon-dioxide-back-into-coal-316011 (https://www.technologynetworks.com/tn/news/turning-carbon-dioxide-back-into-coal-316011)

Quote
The research team led by RMIT University in Melbourne, Australia, have developed a new technique that can efficiently convert CO2 from a gas into solid particles of carbon.

Published in the journal Nature Communications, the research offers an alternative pathway for safely and permanently removing the greenhouse gas from our atmosphere.

Quote
“To date, CO2 has only been converted into a solid at extremely high temperatures, making it industrially unviable.

“By using liquid metals as a catalyst, we’ve shown it’s possible to turn the gas back into carbon at room temperature, in a process that’s efficient and scalable.

“While more research needs to be done, it’s a crucial first step to delivering solid storage of carbon.”

Quote
The CO2 slowly converts into solid flakes of carbon, which are naturally detached from the liquid metal surface, allowing the continuous production of carbonaceous solid.

Esrafilzadeh said the carbon produced could also be used as an electrode.

“A side benefit of the process is that the carbon can hold electrical charge, becoming a supercapacitor, so it could potentially be used as a component in future vehicles.”

“The process also produces synthetic fuel as a by-product, which could also have industrial applications.”
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Sigmetnow on March 23, 2019, 12:09:16 AM
Canadian company gets $68 million to build out ‘negative emissions’ carbon capture tech
Quote
A Canadian company has received $68 million in funding to bring its CO2 capturing technology to market on a commercial scale. The tech is able to pull carbon dioxide directly out of the atmosphere for storage or use.

Carbon Engineering, a clean energy company based in British Columbia, announced the completion of an equity financing round of $68 million. The company said it’s the largest private investment ever made in a Direct Air Capture company.

The company plans on using the money to “commercialize and enter mainstream markets with its fully demonstrated DAC technology that is able to capture and purify atmospheric carbon dioxide (CO2) for under USD $100/tonne.”

Carbon Engineering isn’t the only company to work on Direct Air Capture technology, which captures CO2 from atmospheric air, and puts it into purified form for use or storage. The company says it can deliver large-scale “negative emissions” by “permanently and safely storing the CO2 underground.”

Carbon Engineering can also integrate its DAC technology with its “Air to Fuels” technology. This tech allows the company to convert the CO2 captured from the atmosphere into “ultra-low carbon fuels that can power existing cars, trucks and airplanes without any modifications.” CE says these synthetic “cleaner burning” fuels “are drop-in compatible with today’s engines and infrastructure.”

CE CEO Steve Oldham told the National Post that a 30-acre commercial negative-emissions plant could scrub one megaton of CO2 from the atmosphere each year — the equivalent of planting 40 million trees. ...
https://electrek.co/2019/03/22/negative-emissions-carbon-tech/

I doubt very much that underground gas storage is “permanent and safe.”
And the “ultra-low-carbon Air to Fuel” claims sound too good (and any such fuel too expensive).
But targeting a carbon tax to be at least the cost of CO2 removal would make sense, once the technology is proven.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: rboyd on March 23, 2019, 11:40:56 PM
If we cant make CCS work economically for the highly concentrated CO2 stream coming out of a power station, how can it be economic to capture the much more diffuse levels of CO2 in the atmosphere? How much would the carbon tax have to be, and could we build renewables at a much cheaper cost?
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: interstitial on March 24, 2019, 12:05:30 AM
It would be great in some ways if this were a practical fix. I am very skeptical of the economics of schemes that turn co2 into fuel. Initially the fuel was burned to extract the energy. Due to energy losses in all systems putting the energy back in will require more energy then is extracted on combustion. I didn't look for information on how efficient their process is. Further energy losses in an ice engine are huge. Of the thermal energy produced in combustion modern cars are between 17 and 21% efficient at power to the wheels. BEV's are 59-62% efficient at converting electricity to power to the wheels.
https://fueleconomy.gov/feg/evtech.shtml
I am sure a long discussion could ensue about efficiency numbers. Many higher numbers may report a fraction of the process, say just the efficiency of the engine. I am not claiming these are definitive numbers. I am only trying to make the point that is not a solution. Where would all that energy come from. Wouldn't it be better utilized in a BEV.
I hope I got these CO2 calculations right if not please correct me.
Assuming 420ppm and 290 baseline CO^2 that is 130ppm extra carbon.
Correction (Thats what I get for not checking a calculation on the Internet thanks Crandles) .0130(.0000130) *  44.0095 / 28.97 * 5.148x10^18=1.017*10^17(14) tons of extra co2
Calculation from https://micpohling.wordpress.com/2007/03/30/math-how-much-co2-by-weight-in-the-atmosphere/
At a cost of 100 dollars a ton.
1.017*10^19(16) dollars


1*10^3       one thousand
1*10^6      one million
1*10^9      one billion
1*10^12   one trillion
1*10^15   one quadrillion
1*10^18   one quintillion
So basically 10 quintillion (10 quadrillion)[/b] dollars
I am guessing but probably more than all the money spent in the world throughout time.  Notice also that a 1000 fold reduction in cost to ten cents, a very unlikely prospect, does not make it close to feasible.  Further  just mitigation current CO2 emmisions assuming 2ppm per year would be  1.564*10^1512 dollars or 1.6 quadrillion(trillion) dollars. Even with a thousand fold reduction in cost 1.6 trillion dollars is still a lot of money. (while 1.6 billion dollars is still a lot of money that would be an amount a few governments could afford)  For comparison the entire world economy was 85 trillion in 2018. https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(nominal)
Unless I (did) screwed up somewhere in my calculations I can’t (don't) see how this or any similar tech is anything but a distraction.


Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: b_lumenkraft on March 24, 2019, 06:53:38 AM
Great post Interstitial. Thank you for this.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: rboyd on March 24, 2019, 09:22:40 PM
Agreed
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: crandles on March 25, 2019, 12:32:13 PM
Assuming 420ppm and 290 baseline CO^2 that is 130ppm extra carbon.
.0130 *  44.0095 / 28.97 * 5.148x10^18=1.017*10^17 tons of extra co2

Isn't 130ppm = 130/1000000 = 0.00013 rather than .0130 ?

.

I agree $100 a tonne isn't likely to become 1000 times cheaper. However with scale and familiarity a 10* cheaper effect seems reasonably likely (unless this is already built into the $100 estimate)

Should we instead of despairing, celebrate that perhaps a carbon tax of as small of $11/tonne might get the job done (albeit that is eventually) ?
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: El Cid on March 25, 2019, 03:30:57 PM
Why dont we use plants and soil for carbon capture? All this engineering this, building that?! We have a much cheaper and simpler solution for that. Regenerative agriculture can remove huge amounts of carbon from the atmosphere while at the same time improving our eroding soils. This is the solution for carbon capture, not more machinery .

50 million sqkm (https://ourworldindata.org/yields-and-land-use-in-agriculture#global-agricultural-land-use-today) is used for agriculture. Increasing soil organic matter (in the top 30 cm) by 1% (which is quite feasible in 5-10 yrs with the right methods) increases carbon in the soil by cca 75 gigatons. That is 7 years of emissions!
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Tor Bejnar on March 25, 2019, 05:01:02 PM
Quote
… Increasing soil organic matter (in the top 30 cm) by 1% (which is quite feasible in 5-10 yrs with the right methods) increases carbon in the soil by cca 75 gigatons. That is 7 years of emissions!
Sequestering 7 years of emissions in (about) 7 years would be a great start!  When we start sequestering 10 years of emissions in 7 years, then we'll start heading to 350 ppm (https://350.org/) 'where we belong'.

Of course, I'm all for our learning how to efficiently sequester CO2 from smokestacks (which will continue to be required for steel and cement production, as far as I know).
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: GoSouthYoungins on March 25, 2019, 05:12:29 PM
Why dont we use plants and soil for carbon capture? All this engineering this, building that?! We have a much cheaper and simpler solution for that. Regenerative agriculture can remove huge amounts of carbon from the atmosphere while at the same time improving our eroding soils. This is the solution for carbon capture, not more machinery .

50 million sqkm (https://ourworldindata.org/yields-and-land-use-in-agriculture#global-agricultural-land-use-today) is used for agriculture. Increasing soil organic matter (in the top 30 cm) by 1% (which is quite feasible in 5-10 yrs with the right methods) increases carbon in the soil by cca 75 gigatons. That is 7 years of emissions!

Bingo. Carbon farming. This solution is also the most elegant as it naturally is intertwined with less carbon emitting lifestyles.

The idea that we need to techno-invent a machine that does what plants have evolved to do for billions of years is silly. It is also pointless because the output is a worthless burden, whereas plants (and animals) can produce food and building materials.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: interstitial on March 25, 2019, 06:54:22 PM
I made a calculation error. I corrected the original post. Thanks Crandles for spotting it.  :P
It makes my point substantially weaker but I don't think it is wrong. Given the amount of energy involved going from 100 to 0.10 dollars a ton seems implausible to me.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: jai mitchell on March 30, 2019, 03:36:20 AM
It will be far, far cheaper to establish a Direct Air Capture Industrial Process industry on the scale of the current domestic oil and gas refinery and transportation infrastructure than it will be to build seawalls to keep out the ocean from the U.S.' (much less the world's) cities.

As though sea walls would be successful in preventing the total loss of the world's cities.
 8)
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: rboyd on March 30, 2019, 03:59:46 AM
It worries me that we will end up with a Climate Industrial Complex brought to us by the very industries that created the problems:

- Big Oil and Gas: The expertise to build the pipeline infrastructure needed to transport captured CO2, and the drilling expertise to bury it.

- Big Ag: The planting of "CO2 plantations" of switch grass etc. to capture CO2, then burn for energy, then capture the exhaust CO2 and we are back to Big Oil.

- Big Mining: Massive excavations and crushing of the right types of rocks (the best ones in Brazil and India) to be spread across wet ecosystems to be "weathered", capturing CO2 and transferring alkaline to the oceans.

- Big Military: To protect the above installations

All made at a great profit and counted as additions to GDP. Probably wont save civilization but it will surely be profitable trying.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Tor Bejnar on March 30, 2019, 04:29:22 AM
Well said, rboyd!
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: b_lumenkraft on March 30, 2019, 06:04:11 AM
It worries me that we will end up with a Climate Industrial Complex brought to us by the very industries that created the problems:

- Big Oil and Gas: The expertise to build the pipeline infrastructure needed to transport captured CO2, and the drilling expertise to bury it.

- Big Ag: The planting of "CO2 plantations" of switch grass etc. to capture CO2, then burn for energy, then capture the exhaust CO2 and we are back to Big Oil.

- Big Mining: Massive excavations and crushing of the right types of rocks (the best ones in Brazil and India) to be spread across wet ecosystems to be "weathered", capturing CO2 and transferring alkaline to the oceans.

- Big Military: To protect the above installations

All made at a great profit and counted as additions to GDP. Probably wont save civilization but it will surely be profitable trying.

Though, i have no problem with millions and millions of soldiers all over the world planting trees (which would actually work to capture CO2).  8)
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: El Cid on March 30, 2019, 08:37:16 AM
Well said, rboyd!

I second that. Also, as I and GSY have said above, we have the "technology" already: carbon farming, which while capturing carbon, improves the soil and protects the ecosystem, promotes biodiversity. We dont need big ag, we need regenerative ag...
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: oren on March 30, 2019, 10:51:07 AM
Even cheaper than carbon capture: pooling all available resources towards solar and wind generation, batteries and grid interconnects, will mean that we avoid emitting lots of that CO2 to begin with.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: GoSouthYoungins on March 30, 2019, 01:01:04 PM
Well said, rboyd!

I second that. Also, as I and GSY have said above, we have the "technology" already: carbon farming, which while capturing carbon, improves the soil and protects the ecosystem, promotes biodiversity. We dont need big ag, we need regenerative ag...

We need policies that incentivize a more permaculturish lifestyle and disincentivize high energy lifestyles. We also need policies that place more value on human labor and less on high energy machine labor. Luckily it is all the same simple policy. Every else is noise.

Steep carbon tax that gets redistributed back to each person.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: interstitial on March 30, 2019, 07:58:20 PM
agreed Oren. That is my point as well the removal of CO2 is more expensive than switching to renewables. Also it would be a continual expense until we made replaced all co2 sources. I once heard that an ancient Chinese definition of insanity was trying to drain a pond without diverting the inflow first. Not sure if that is true but that seems to be what we are talking about here. In fact as recently reported in one of the other threads on this site switching to renewables is cheaper than operating many older power stations.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Tor Bejnar on April 10, 2019, 08:02:57 PM
The breakthrough that could actually reverse climate change
 (http://By Grist Creative on Apr 8, 2019)By Grist Creative on Apr 8, 2019

turning captured CO2 in concrete aggregate (the pebbles and sand, not the cement)

Quote

By some accounts, concrete alone is responsible for 4-8 percent of the world’s CO2 emissions. And it’s only getting worse. Between 2011 and 2013, China used more cement than the United States used in all of the 20th century — about enough to pave paradise and put up a parking lot the size of Hawaii’s Big Island. Cement production worldwide could grow another 23 percent by 2050.

To do that, the Foundation for Climate Restoration estimates that a trillion tons of CO2 must be removed from our atmosphere on top of additional efforts to curb emissions. The National Academies of Science agrees that “negative emissions technologies,” as they’re known, are essential.

Blue Planet’s process starts with collecting CO2 and dissolving it in a solution. In the process, the company creates carbonate that reacts with calcium from waste materials or rock to create calcium carbonate. Calcium carbonate happens to be the main ingredient in limestone. But rather than superheating it to create cement (which would release all that CO2 right back into the atmosphere), Constantz and his team turn the resulting stone into pebbles that serve as aggregate.

This is easiest to do where there’s lots of CO2 — smokestacks at factories, refineries and power plants, for example — but it can also come from “direct air capture,” using less concentrated air anywhere, a technology whose costs are rapidly declining.

Blue Planet’s limestone, created using emissions collected from the Moss Landing Power Plant on Monterey Bay and other sources, has already been added to concrete in areas of San Francisco International Airport. Constantz expects to open its first commercial production facility in the Bay Area within the year, producing a little over 300,000 tons of rock annually with C02 captured from an adjacent power plant’s exhaust stack.
[emphasis added]
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on April 30, 2019, 07:07:34 PM
An Irish company has made artificial trees that can capture and compress CO2 into a liquid for under $100 per ton.  That's significant because it can be sold to beverage companies and fire extinguisher manufacturers at that price.

https://oilprice.com/Latest-Energy-News/World-News/Metal-Trees-Suck-Up-CO2-From-Air.html (https://oilprice.com/Latest-Energy-News/World-News/Metal-Trees-Suck-Up-CO2-From-Air.html)

Quote
An Irish-based company has designed CO2-sucking metal columns that can clean up part of the carbon emissions released by cars. The company plans to install 1,200 such “metal trees” in the United States after a two-year test in Arizona proved they work, Reuters reports.

Silicon Kingdom Holdings says its method of carbon capture is cheaper than others and it’s also effective: the 1,200 columns to be erected in the U.S. in the next stage of the company’s climate change fighting efforts can remove the annual emissions from 8,000 cars, or 36,500 metric tons of carbon dioxide. This may not be a whole lot given there were more than 270 million cars on U.S. roads last year, but it is a start.

Quote
Direct carbon capture, or sucking the compound directly from the air, is a new field of research with only a few companies active, Jennifer Wilcox from Worcester Polytechnic Institute told Reuters. The reason is that the technology is more expensive than non-direct carbon capture methods. However, this is not the case with the Silicon Kingdom Holdings metal trees. Their technology, according to the researcher who invented it, Klaus Lackner, costs less than US$100 per ton of pure carbon dioxide.

What makes the technology particularly promising is the fact that the carbon dioxide can be reused in a range of applications after being captured.

“You can buy liquid CO2 which is delivered by truck in order to fill fire extinguishers and myriad other things for prices between $100 and $200 a ton,” Lackner told Reuters.

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: sidd on April 30, 2019, 09:58:36 PM
Any idea of the process details ? How exactly do they capture CO2 ?

sidd
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on May 01, 2019, 12:53:59 AM
Any idea of the process details ? How exactly do they capture CO2 ?

sidd

I think that's proprietary information.  I found the press release from Arizona State University who is partnering with them on the project.

https://www.apnews.com/Business%20Wire/f0edc67131d04d2dbd7a531ebdecd422 (https://www.apnews.com/Business%20Wire/f0edc67131d04d2dbd7a531ebdecd422)

Quote
Unlike other carbon capture technologies, SKH’s technology can remove CO 2 from the atmosphere without the need to draw air through the system mechanically, using energy intensive devices. Instead, the technology uses the wind to blow air through the system. This makes it a passive, relatively low-cost and scalable solution that is commercially viable. If deployed at scale, the technology could lead to significant reductions in the levels of CO 2 in Earth’s atmosphere, helping to combat global warming.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: sidd on May 01, 2019, 06:02:14 AM
"proprietary technology"

Mmmm. I might believe it sfter they disclose the chemistry, physics and engineering in the patents. Or lack thereof. I can work out the economics myself.

sidd

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: NeilT on May 01, 2019, 11:46:33 AM
Of course there is Kelp (http://carboninstitute.org/kelp-and-carbon-sequestration-bringing-terrestrial-carbon-accounting-to-the-deep-sea/).

I have read about this possibility over the last decade or so but it never really seems to crystallise into anything.  It is always the "technical" solution which must be built "at a cost" which grabs the headlines.

The planet is 2/3 water, so finding a space to grow the kelp is less of an issue and most of that water area is International and not claimed for farming or other uses.

There are issues though.  Such as control and management, reducing CO2 is one thing, but the consequences of exponential growth of kelp are another.

When we talk about spending trillions of $ on solutions, then we really do have to start thinking about engineering projects.  Large scale solar has opened up possibilities which didn't exist before.  Projects which were totally off the scale in terms of probability become viable.  Such as spending the money to cut a canal from the ocean to lake Eyrie in Australia; then using very large scale solar to produce desalinated water to irrigate carbon capture agriculture in the area.  Equally this is a possibility for the Sahara too.  Not to create some mythical ocean but to bring the raw material (seawater), to the area in order to produce the fuel for transition (clean water), for creating a new carbon sink.

Israel is the most advanced in the world for capturing and sequestering water into arid environments in order to create agriculture and make desert land bloom.  About time people started talking to them.

At the turn of the century the political atmosphere was all about "cost" and "return on investment" for natural geoengineering solutions.  I note that this attitude is starting to change today.  Paying Brazil to protect the Amazon is a short term solution which will, in the end, fail.  Because there is always more money to be made from destroying the Amazon than the rest of the world is willing to pay to protect it.

Whilst BEV is a good step in the right direction, let us not forget that vehicles are only 1/3 of the problem in the western world and a lot less than that in the undeveloped world.  Power, heating and deforestation are 2/3 of the problem and BEV will do absolutely nothing about that.  In fact it will exacerbate Power.

As has been said many times on these forums, there is no single solution which you can point at and say "see if you just spend money on that it will fix the problem".  There isn't.  For 150 years the entire planet has been cutting down, digging up and burning the carbon sinks of the planet.  Just like a diet and weight loss, that will not be fixed by simply moderating our consumption.  If we want to reduce our CO2 in the atmosphere we need to remove more than we put in.  Just like a diet and weight loss.

The problem with AGW and CO2 in the atmosphere is that it has taken the whole planet 150 years to get us to where we are and, rather than slowing down, we are speeding up and emitting more.  Simply changing vehicles to Electric then consuming fossil powered fuel in a more efficient way will not fix it.  It will extend the final date on which the cost must be paid in lives.  But it will not pay the debt in an other way.

The path is totally clear.  Move to CO2 neutral consumption of power.  Remove the existing CO2 from the atmosphere.  We don't have to wait for the first to start on the second.  But we have to do Both.

The message is also clear.  Biotechnology has the possibility to capture and sequestrate far more CO2 than any politically feasible mechanical sequestration.  Bio sequestration has the benefit of being self sustaining, self replicating and incredibly efficient.  The problem is that it takes space.

You would assume that the very first place people would have looked to capture CO2 directly from the air would have been places that people don't live.  Sadly that requires more money than is currently available to fix the problem.

There was a time, not so long ago, when the political environment was such that no action would ever be taken on a problem until it was 50% of the way to catastrophe.  If you equate that to something which is infesting the seas and doubling in size every day; then when the politicians decide to act they have ONE day to fix the problem.

This is analogous to climate change via CO2 emissions.  Early and dramatic action would be best and cheapest.  In fact nothing really substantial will happen until the possibility of a continued life as we know it is virtually nil.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: gerontocrat on May 01, 2019, 01:27:57 PM
Of course there is kelp

The planet is 2/3 water, so finding a space to grow the kelp is less of an issue and most of that water area is International and not claimed for farming or other uses.

"The planet is 2/3 water". So what.

Kelp is attached to the sea floor, and grows in shallow seas (<50 metres depth?) in environments within a restricted temperature range. Kelp is also vulnerable to invasive species such as sea urchins and pollution (e.g. nutrient run-off from agriculture and, would you believe, levels of CO2 in the water)..

So the places where kelp can grow are very restricted - a coastal fringe at a small range of temperatures.
Existing kelp forests are under threat.

The question is whether existing kelp forests will survive.

https://www.nationalfisherman.com/northeast/maine-seaweed-landings-value-grow-as-southern-kelp-forests-decline/
https://vancouverisland.ctvnews.ca/old-british-naval-maps-shine-light-on-decline-of-b-c-kelp-forests-1.4316994
https://www.sciencedaily.com/releases/2019/02/190206101129.htm Underwater forests threatened by future climate change, new study finds
https://www.sciencedaily.com/releases/2013/07/130717095215.htm The researchers have found a combined effect on kelp forests from nutrient pollution and higher CO2, which could have a devastating impact on Australia's marine ecosystems.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: NeilT on May 01, 2019, 02:00:48 PM
All true.  However  if we're going to go into large scale engineering, creating artificial shallow land for them (floating even), is not beyond our capabilities.

The big boost is that the challenges of land ownership and change of land use do not exist.

There is plenty of sea warm enough to allow Kelp to grow and it does not need any active farming as such.  Just an environment to live in and seeding to grow.  Something, apparently, we're pretty good at.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: mitch on May 01, 2019, 04:50:03 PM
The problem with direct air capture of CO2 is what to do with it afterwards.  CO2 has roughly 2.7 times the mass of the original hydrocarbons, so need places with lots of room or where it can be reacted with basalt to fix it as CaCO3.  You could pump it into the ocean where there is plenty of buffer capacity, but that isn't good for the ocean biosphere. 

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: crandles on May 01, 2019, 05:36:10 PM
The problem with direct air capture of CO2 is what to do with it afterwards.  CO2 has roughly 2.7 times the mass of the original hydrocarbons, so need places with lots of room or where it can be reacted with basalt to fix it as CaCO3.  You could pump it into the ocean where there is plenty of buffer capacity, but that isn't good for the ocean biosphere.

Building materials, carbon composites in place of aluminium / concrete / bricks sounds like a good idea to me but whether it can be made cost effective (or nearly so and mandated by building regs) remains to be seen.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Sleepy on May 24, 2019, 10:29:36 AM
Outlining the risks and challenges for the US.
https://rhg.com/research/capturing-leadership-policies-for-the-us-to-advance-direct-air-capture-technology/ (https://rhg.com/research/capturing-leadership-policies-for-the-us-to-advance-direct-air-capture-technology/)

Last year, global CO2 emissions reached an all-time high. Recent scientific research indicates that global emissions need to reach net-zero between 2045 and 2055 to limit global temperature rise to 1.5 degrees Celsius. DAC technology does not make it possible to bypass the difficult work of reducing emissions. We find that even with break-neck electrification of vehicles, buildings, and industry, unprecedented improvements in energy efficiency, completely decarbonized power generation, and carbon removal from enhanced natural sequestration, DAC technology will be essential for the US to decarbonize by midcentury. Our analysis indicates that for the US to reach net-zero emissions by 2045 (our “100by45” scenarios) between 560 and 1,850 million metric tons of CO2 will need to be removed by DAC technology and then permanently stored underground annually, depending on the availability of other carbon removal options, such as bioenergy with carbon capture and storage (BECCS) and natural sequestration, and the pace of electrification in the transportation, buildings, and industrial sectors.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Tom_Mazanec on June 11, 2019, 07:20:53 PM
Sequestration off CO2 with microbes:
https://www.financialexpress.com/lifestyle/science/new-technology-to-combat-climate-change-scientists-develop-microbes-to-convert-co2-into-plastics-fuels/1604018/
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: b_lumenkraft on June 11, 2019, 07:30:20 PM
From Toms link:

Quote
The project began in 2013, when researchers started exploring the broad potential of nanoscopic quantum dots, which are tiny semiconductors similar to those used in television sets. Quantum dots can be injected into cells passively and are designed to attach and self-assemble to desired enzymes and then activate these enzymes on command using specific wavelengths of light. Nagpal wanted to see if quantum dots could act as a spark plug to fire particular enzymes within microbial cells that have the means to convert airborne CO2 and nitrogen, but do not do so naturally due to a lack of photosynthesis. By diffusing the specially-tailored dots into the cells of common microbial species found in soil, the researchers bridged the gap.
Now, exposure to even small amounts of indirect sunlight would activate the microbes’ CO2 appetite, without a need for any source of energy or food to carry out the energy-intensive biochemical conversions. “Each cell is making millions of these chemicals and we showed they could exceed their natural yield by close to 200 percent,” Nagpal said. The microbes, which lie dormant in water, release their resulting product to the surface, where it can be skimmed off and harvested for manufacturing. Different combinations of dots and light produce different products: Green wavelengths cause the bacteria to consume nitrogen and produce ammonia while redder wavelengths make the microbes feast on CO2 to produce plastic instead.

Of all the geoengineering ideas i heard this might be the least stupid one.

Even though, i remain extremely sceptical. You need chemicals, light and electronics. So, my key argument remains, why not just build solar cells and wind turbines with these resources?
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: nanning on June 12, 2019, 07:57:51 AM
From what b_lumenkraft quoted:
Quote
Quantum dots can be injected into cells passively and are designed to attach and self-assemble to desired enzymes and then activate these enzymes on command
I almost get angry from how humans treat other life on Earth, what's left of it. To abuse other lifeforms and call it technology, bah. And still going full BAU. The supremacy is strong in this one.

We have to stop our emissions now! No more heating your house, no more ICE use etc. 'Just' stop doing it. Get you annual carbon footprint <100kg (I did). Do what it takes. It is paramount. Change everything accordingly. To hell with the economy and consumering. the Amazon indiginous un-contacted tribes have a nice and happy and full life in an intimate group, with nature. It can be done!
Sorry about the inconvenience.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: sidd on June 12, 2019, 08:04:49 AM
"No more heating your house"

Hard sell in midwest winter.

"no more ICE use etc."

Another hard sell for communities with no public transport.

"'Just' stop doing it. "

Good luck with that. Even the Amish have the English (non Amish) drive em places.

Out of curiosity,  what about taxes ? I'm paying for the Pentagon burning fuel like there was no tomorrow bombing people. Or have you gone full Amish ? I am considering that.

sidd

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Bob Wallace on June 13, 2019, 07:23:14 AM
Quote
To hell with the economy and consumering. the Amazon indiginous un-contacted tribes have a nice and happy and full life in an intimate group, with nature. It can be done!

It could be done but it won't be done.  At least not done by enough individuals to make even a small dent in our GHG emissions.  Most people are simply not going to make significant lifestyle changes. 

What we have to do is to give people acceptable alternatives.  Give them alternatives that don't require bothersome change and cost no more than what they are leaving behind. 

And luckily we can already provide a large portion of the alternatives.  We can generate electricity without fossil fuels and the cost of electricity should drop.  EVs should soon be roughly the same purchase price as ICEVs and cost much less per mile to operate.  We're already starting to run short distance boats and planes on electricity stored in batteries.  Long distance flight and transoceanic shipping are the major nuts left to crack.

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: b_lumenkraft on June 13, 2019, 07:48:10 AM
Long distance flight and transoceanic shipping are the major nuts left to crack.

Easy to crack: A >$150 carbon tax!
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Bob Wallace on June 13, 2019, 08:13:48 AM
Long distance flight and transoceanic shipping are the major nuts left to crack.

Easy to crack: A >$150 carbon tax!

That's a way to do it but implementation would be very difficult.  We can probably get away with carbon taxes on electricity generation by feeding the revenues back in at the consumer level so that electricity prices are increased.  But put a large carbon tax on jet fuel and out come the torches and pitchforks.  There's no reasonable alternative for traveling long distances in a short amount of time.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: b_lumenkraft on June 13, 2019, 08:46:49 AM
But put a large carbon tax on jet fuel and out come the torches and pitchforks

I don't know about that. You would have been absolutely right last year. But i can see the public opinion turning.

The carbon tax totally makes sense and is easy to implement. It's the one thing we should all fight for.

Some more blockades, protests, strikes, civil disobedience, droned airports, activism... We could get there.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: SteveMDFP on June 13, 2019, 05:02:44 PM
   But put a large carbon tax on jet fuel and out come the torches and pitchforks.  There's no reasonable alternative for traveling long distances in a short amount of time.

I think biofuels would be appropriate for these two transportation needs.  Wouldn't be hard to get there if we stopped using biofuels for other purposes.  For example, huge amounts of corn in the US go to make ethanol to mix with gasoline--a fundamentally stupid policy. 
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on June 13, 2019, 06:58:04 PM
Indigo, a new start-up company, is paying farmers $15 per ton of carbon stored based on soil measurements.  They'll provide training on no-till techniques to ensure the carbon stays in the soil.

https://www.washingtonpost.com/business/2019/06/12/new-plan-remove-trillion-tons-carbon-dioxide-atmosphere-bury-it/?utm_term=.6c4124742c8a (https://www.washingtonpost.com/business/2019/06/12/new-plan-remove-trillion-tons-carbon-dioxide-atmosphere-bury-it/?utm_term=.6c4124742c8a)

Quote
The most prominent efforts to prevent that crisis involve reducing carbon emissions. But another idea is also starting to gain traction — sucking all that carbon out of the atmosphere and storing it underground.

It sounds like an idea plucked from science fiction, but the reality is that trees and plants already do it, breathing carbon dioxide and then depositing it via roots and decay into the soil. That’s why consumers and companies often “offset” their carbon emissions by planting carbon-sucking trees elsewhere in the world.

But an upstart company, ­Boston-based Indigo AG, now wants to transform farming practices so that agriculture becomes quite the opposite of what it is today — a major source of greenhouse gas emissions.

By promoting techniques that increase the potential of agricultural land to suck in carbon, the backers of Indigo AG believe they can set the foundation for a major effort to stem climate change. On Wednesday, the company announced a new initiative with the ambitious goal of removing 1 trillion tons of carbon dioxide from the atmosphere by paying farmers to modify their practices.

Called the Terraton Initiative (a “teraton” is a trillion tons), the company forecasts that the initiative will sign up 3,000 farmers globally with more than 1 million acres in 2019.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Bob Wallace on June 14, 2019, 04:55:55 AM
   But put a large carbon tax on jet fuel and out come the torches and pitchforks.  There's no reasonable alternative for traveling long distances in a short amount of time.

I think biofuels would be appropriate for these two transportation needs.  Wouldn't be hard to get there if we stopped using biofuels for other purposes.  For example, huge amounts of corn in the US go to make ethanol to mix with gasoline--a fundamentally stupid policy.

We are going to need to feed an increasing number of people for a several more years as we reach peak population and work our numbers back down.  And as we continue to heat the planet and make our weather weirder we're likely to see lots of fields not produce each year.  Biofuels could power ships and planes but there's a question of whether we could produce enough.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Bob Wallace on June 14, 2019, 04:59:47 AM
But put a large carbon tax on jet fuel and out come the torches and pitchforks

I don't know about that. You would have been absolutely right last year. But i can see the public opinion turning.


Public sentiment is turning but I don't think we're "there" yet. 

I live in one of the most liberal parts of the country and I'm watching some of our ecological types oppose a new wind farm that would be hard to see from almost every part of the county.  NIMBY from the greens. 
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: b_lumenkraft on June 14, 2019, 05:22:01 AM
NIMBY from the greens.

Those are the worst. People who oppose wind turbines while 'being green' is like the definition of Dunning–Kruger effect.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Tom_Mazanec on June 19, 2019, 05:55:49 PM
Floating solar islands to turn CO2 into alternate fuel:
https://weather.com/science/environment/news/2019-06-18-floating-islands-solar-carbon-methanol:
https://weather.com/science/environment/news/2019-06-18-floating-islands-solar-carbon-methanol
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Bob Wallace on June 19, 2019, 06:49:52 PM
Floating solar islands to turn CO2 into alternate fuel:
https://weather.com/science/environment/news/2019-06-18-floating-islands-solar-carbon-methanol:
https://weather.com/science/environment/news/2019-06-18-floating-islands-solar-carbon-methanol

Sounds expensive.  More likely we'll see wind and solar electricity used for electrolysis to generate hydrogen which will then be converted into a more usable fuel form.

Having lived a few years floating on oceans I have an appreciation of how corrosive salt water can be.  Floating solar farms on fresh water is something entirely different.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: rboyd on June 19, 2019, 06:51:51 PM
The Great Lakes covered in solar panels and wind turbines, the price of the future?
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Bob Wallace on June 19, 2019, 07:11:15 PM
The Great Lakes covered in solar panels and wind turbines, the price of the future?

No, you hugely, hugely overestimate the amount of land required for a 100% RE future.  Some wind turbines not too far from major population centers (minimize transmission costs while minimizing aesthetic objections).  And no floating solar installation on large bodies of water subject to major storms and major ice events.

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: gerontocrat on June 19, 2019, 08:31:30 PM
The Great Lakes covered in solar panels and wind turbines, the price of the future?

No, you hugely, hugely overestimate the amount of land required for a 100% RE future.  Some wind turbines not too far from major population centers (minimize transmission costs while minimizing aesthetic objections).  And no floating solar installation on large bodies of water subject to major storms and major ice events.
One thing that Musk has got about right.

Quote
“If you wanted to power the entire United States with solar panels, it would take a fairly small corner of Nevada or Texas or Utah; you only need about 100 miles by 100 miles of solar panels to power the entire United States,” Musk said at at the event in Rhode Island. “The batteries you need to store the energy, so you have 24/7 power, is 1 mile by 1 mile. One square-mile.”

One of many visualisations that have failed to kick this misconception into the bin is attached
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Bob Wallace on June 19, 2019, 08:42:31 PM
100 x 100 square miles of panels to supply the United States with all the energy it needs = 10,000 mi².

Area of the Great Lakes = 94,250 mi².
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: rboyd on June 20, 2019, 05:25:27 AM
Only when the sun is shining and it is not cloudy.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: sidd on June 20, 2019, 05:32:17 AM
Speaking of cloudy days:

https://www.sciencealert.com/black-silicon-solar-cells-have-just-hit-a-record-breaking-22-1-efficiency

sidd
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: GoSouthYoungins on June 20, 2019, 07:55:01 AM
Floating solar islands to turn CO2 into alternate fuel:
https://weather.com/science/environment/news/2019-06-18-floating-islands-solar-carbon-methanol:
https://weather.com/science/environment/news/2019-06-18-floating-islands-solar-carbon-methanol

"The present work initiates the development of this concept and highlights relevant questions in physics, chemistry and mechanics."


Simple translation: This shit doesn't work.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: GoSouthYoungins on June 20, 2019, 07:57:19 AM
to kick this misconception into the bin is attached

One of many visualisations that have failed to understand the way energy is utilized.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: RikW on June 20, 2019, 09:45:14 AM
Well, theoretically he is probably correct.

Just calculate the electricity (or energy?) consumption in the USA.
Calculate how many energy a solar panel generates
Divide et voila!

And same for the battery-pack required. The math isn't that hard i guess and such a map gives a good impression what part of the USA is required to power the whole of the USA;

And putting a square next to it with solar-panel-available roofs would also be good idea
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Bob Wallace on June 20, 2019, 07:50:14 PM
to kick this misconception into the bin is attached

One of many visualisations that have failed to understand the way energy is utilized.

Can you give us more detail rather than just a simple dismissal?

Let's assume, just for the sake of the argument, that 100x100 miles of solar panels would generate as many TWh of electricity as the US uses annually.  How much storage would it take to turn that output into a 24/365 reliable electricity source for the US?
--

Obviously a 100% solar feed is not optimal.  The best solution will involve wind and other renewables as their inclusion lowers the need for storage.  But just play along and explain your thinking regarding 100% solar and storage.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on June 20, 2019, 08:17:42 PM
to kick this misconception into the bin is attached

One of many visualisations that have failed to understand the way energy is utilized.

Can you give us more detail rather than just a simple dismissal?

Let's assume, just for the sake of the argument, that 100x100 miles of solar panels would generate as many TWh of electricity as the US uses annually.  How much storage would it take to turn that output into a 24/365 reliable electricity source for the US?
--

Obviously a 100% solar feed is not optimal.  The best solution will involve wind and other renewables as their inclusion lowers the need for storage.  But just play along and explain your thinking regarding 100% solar and storage.

You don't have to go 100% solar.  There's wind (which often blows at night, alleviating some of the intermittency), hydro (avail 24/7 if there's not a drought), geothermal (also available 24/7) and still some nuclear operating (with small modular reactors possible if they can be made economically).  So the area need is even less than depicted and much of it can be on rooftops or over parking lots.

The point of the graphic is that the "renewables take up too much room" argument is pure B.S.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Bob Wallace on June 20, 2019, 09:05:47 PM
Ken - fully understand and agree.

But I want Mr. Youngins to explain with some facts and details why Musk's math is wrong.  If he can. 

I'm also waiting for his explanation for why Tesla will fail if they spend no more in Q2 2019 than previous profitable quarters while selling a record number of cars.  He's been on the site since I posted that request but has yet to share his wisdom.

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: gerontocrat on June 20, 2019, 09:14:42 PM
to kick this misconception into the bin is attached

One of many visualisations that have failed to understand the way energy is utilized.

Can you give us more detail rather than just a simple dismissal?

Let's assume, just for the sake of the argument, that 100x100 miles of solar panels would generate as many TWh of electricity as the US uses annually.  How much storage would it take to turn that output into a 24/365 reliable electricity source for the US?
--

Obviously a 100% solar feed is not optimal.  The best solution will involve wind and other renewables as their inclusion lowers the need for storage.  But just play along and explain your thinking regarding 100% solar and storage.
For goodness' sake. It was a simple visual. No-one is suggesting that a 100 x 100 mile solar plant will be built.

No-one is suggesting that wind is not a major source as well.

We all know various storage mechanisms will be required, batteries, hydro and maybe still some LNG plants as extra back-up.

We all know that utilities will need to change their grids and computerised management systems to deal with a new pattern of electricity production, storage and consumption.

Most of us on this forum know that we can get most of the way to zero-carbon electricity with the technology that already exists. (And that is known by many of the Republicans on Capitol Hill)

I also believe that carbon will have to be captured. The concern is that many of the solutions mooted will make new problems greater than the one they are supposed to solve.

And that's all I'm going to say about that
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Bob Wallace on June 20, 2019, 09:26:38 PM
to kick this misconception into the bin is attached

One of many visualisations that have failed to understand the way energy is utilized.

Can you give us more detail rather than just a simple dismissal?

Let's assume, just for the sake of the argument, that 100x100 miles of solar panels would generate as many TWh of electricity as the US uses annually.  How much storage would it take to turn that output into a 24/365 reliable electricity source for the US?
--

Obviously a 100% solar feed is not optimal.  The best solution will involve wind and other renewables as their inclusion lowers the need for storage.  But just play along and explain your thinking regarding 100% solar and storage.
For goodness' sake. It was a simple visual. No-one is suggesting that a 100 x 100 mile solar plant will be built.

No-one is suggesting that wind is not a major source as well.

We all know various storage mechanisms will be required, batteries, hydro and maybe still some LNG plants as extra back-up.

We all know that utilities will need to change their grids and computerised management systems to deal with a new pattern of electricity production, storage and consumption.

Most of us on this forum know that we can get most of the way to zero-carbon electricity with the technology that already exists. (And that is known by many of the Republicans on Capitol Hill)

I also believe that carbon will have to be captured. The concern is that many of the solutions mooted will make new problems greater than the one they are supposed to solve.

And that's all I'm going to say about that

You are not tracking the discussion very well.

Mr. Youngins made a specific claim.  I've asked him to back it up.

No one, including Elon Musk, says we should take a 100x100 area in the US and install all our solar there and use nothing but solar.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: b_lumenkraft on June 20, 2019, 09:42:25 PM

Mr. Youngins made a specific claim.  I've asked him to back it up.

Sorry to say that Bob, but i'm afraid this is not going to happen. You'll not get a substantial answer from them. I tried and failed hard myself.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Tom_Mazanec on July 30, 2019, 07:25:09 PM
DAC is not enough:
https://news.umich.edu/climate-change-why-removing-co2-from-the-air-wont-be-enough/
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: jai mitchell on July 30, 2019, 09:02:02 PM
I like the idea of running an underwater conveyor that transits offshore wind platforms to grow kelp.  As the kelp grows it begins to move into the shore where the kelp is harvested and the grow medium is reseeded as the conveyor goes back out. 


The kelp can be used as cattle feed supplement, for other consumption if desired but can also be dried and converted into biochar for agricultural supplement, though transportation via zero emissions methods will be needed.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on August 02, 2019, 10:27:30 PM
DAC is not enough:
https://news.umich.edu/climate-change-why-removing-co2-from-the-air-wont-be-enough/

DAC wont be the only solution.  It's one of the tools that must be deployed to draw down the carbon that's already in the atmosphere. 

Fossil fuels are already on the way out.  Renewables have made great progress and are now cheaper than fossil fuels in most of the world.  Battery electric vehicles will be outselling ICE vehicles within the next decade.  Methods to make concrete and steel without emitting carbon are being deployed now.  That takes care of most of the future emissions.

However, eventually we need to decrease the carbon dioxide concentrations in the atmosphere from where they peak (probably around 450 ppm) to around 350 ppm.  It would take centuries to millennia for that to happen by natural causes.

Biochar and biomass burning with carbon sequestration is another big part of the solution.  The biochar can be used to help replenish soils in agriculture or reforest projects.  The biogas generated in making the biochar will replace fossil fuel natural gas in other applications (such as building heating and cooking) until they're fully electrified.  However, biomass and biogas burning just recycle the carbon already in the atmosphere.

That's where DAC comes in.  Unlike the renewables and biochar/biogas however, there isn't a payback for capturing the CO2, beyond a few industrial uses.   Most of the captured CO2 will need to be sequestered underground.  So few private sector entities will build DAC facilities.  They'll need to be government funded and run, much like sewage treatment plants.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: petm on August 02, 2019, 11:11:44 PM
Fossil fuels are already on the way out.

Far too little, far too late.

https://ourworldindata.org/grapher/global-primary-energy

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: TerryM on August 03, 2019, 01:14:49 AM
An acquaintance friend was the chief engineer on a huge coal facility near Java. It captured the CO2 as designed, but the fuel costs were enormous - a 35% loss in efficiency.
They ran it with the apparatus in place for less than 2 weeks before deciding that it just wasn't economically feasible.


Terry
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: rboyd on August 04, 2019, 10:31:30 PM
The answer would be a meaningful carbon tax that forces such installations economic. I am very uncomfortable with CCS and DACS as they may serve to elongate the use of fossil fuels, and delay the move to renewables, but in the situation we are in we will need the adoption of every possible solution.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: DrTskoul on August 04, 2019, 10:33:54 PM
I am only uncomfortable with DACS, as it has not been proven yet that the CO2 balance is negative ...
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: rboyd on August 04, 2019, 10:43:22 PM
A very good point ....
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: jai mitchell on August 05, 2019, 07:59:58 PM
DAC is not enough:
https://news.umich.edu/climate-change-why-removing-co2-from-the-air-wont-be-enough/

Quote
In order to stay below the 2-degree mark, all sectors must reduce emissions by 70%.

This article is a joke as it doesn't address the physical reality of the climate catastrophe and our critical need for direct action and massive national mobilization to immediately move toward a zero emissions and (in the next decade or so) negative emissions through regenerative agriculture and DIRECT air capture to prevent 4C globally by 2065.

Please see the first post on this thread.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on August 09, 2019, 08:46:28 PM
DAC is not enough:
https://news.umich.edu/climate-change-why-removing-co2-from-the-air-wont-be-enough/

Quote
In order to stay below the 2-degree mark, all sectors must reduce emissions by 70%.

This article is a joke as it doesn't address the physical reality of the climate catastrophe and our critical need for direct action and massive national mobilization to immediately move toward a zero emissions and (in the next decade or so) negative emissions through regenerative agriculture and DIRECT air capture to prevent 4C globally by 2065.

Please see the first post on this thread.

There are no realistic scenarios that lead to a 4C global increase by 2065. 

Here's what the IPCC report in 2018 stated about near-term temperature increases:

https://www.ipcc.ch/sr15/chapter/spm/ (https://www.ipcc.ch/sr15/chapter/spm/)

Quote
A.1. Human activities are estimated to have caused approximately 1.0°C of global warming5 above pre-industrial levels, with a likely range of 0.8°C to 1.2°C. Global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate. (high confidence) (Figure SPM.1) {1.2}

A.1.1. Reflecting the long-term warming trend since pre-industrial times, observed global mean surface temperature (GMST) for the decade 2006–2015 was 0.87°C (likely between 0.75°C and 0.99°C)6 higher than the average over the 1850–1900 period (very high confidence). Estimated anthropogenic global warming matches the level of observed warming to within ±20% (likely range). Estimated anthropogenic global warming is currently increasing at 0.2°C (likely between 0.1°C and 0.3°C) per decade due to past and ongoing emissions (high confidence). {1.2.1, Table 1.1, 1.2.4}

Given that coal is rapidly being phased out and replaced by renewables, the warming rate will be decreasing, not increasing, over the next few years.

The IPCC report states that Carbon Dioxide Removal will be needed to prevent overshoot of 1.5C though, which is why this topic is important.

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C.3. All pathways that limit global warming to 1.5°C with limited or no overshoot project the use of carbon dioxide removal (CDR) on the order of 100–1000 GtCO2 over the 21st century. CDR would be used to compensate for residual emissions and, in most cases, achieve net negative emissions to return global warming to 1.5°C following a peak (high confidence). CDR deployment of several hundreds of GtCO2 is subject to multiple feasibility and sustainability constraints (high confidence). Significant near-term emissions reductions and measures to lower energy and land demand can limit CDR deployment to a few hundred GtCO2 without reliance on bioenergy with carbon capture and storage (BECCS) (high confidence). {2.3, 2.4, 3.6.2, 4.3, 5.4}
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: rboyd on August 09, 2019, 09:00:34 PM
Please see my comment on the UN IPCC in the renewable energy thread. The blind by institutional design (UN IPCC) leading the blind by propaganda (the population). With a realistic assumption for ECS, an acceptance that Nat Gas is as bad as coal (fugitive methane emissions), and what Brazil will be doing to the Amazon, 4 degrees is easily doable. Please be educated by AbruptSLR.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Tor Bejnar on August 09, 2019, 10:07:01 PM
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There are no realistic scenarios that lead to a 4C global increase by 2065.
This may or may not be true at this time, but 1.5C will undoubtedly be disastrous for civilization as we know it, because 1C which we already have is disastrous for parts of civilization right now.  (Oh, your house hasn't been flooded yet?  How about that cancelled trip to Blue-green-algae-land, Florida (https://floridadep.gov/AlgalBloom)?) 

What we do know (from this forum) is that there are many forcings that have not yet been fed into climate models because they are little understood or only recently discerned, and scientists have been shying from 'what's the worst that can happen, realistically'.   In a few years (next IPCC), a 4C future in my kid's life time may be painfully 'realistic'.  Lloyds of London is famous for insuring odd things (and making money doing so); I wonder what odds they are giving for "no 4C increase by 2065".  We're gambling with our future and most of us are placing all our bets on 'it can't be that bad'. 

Rboyd responded well, too.

Therefore, I sure hope scientists and engineers working on DAC find some nifty solutions, pronto!
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: DrTskoul on August 09, 2019, 10:15:45 PM
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There are no realistic scenarios that lead to a 4C global increase by 2065.
This may or may not be true at this time, but 1.5C will undoubtedly be disastrous for civilization as we know it, because 1C which we already have is disastrous for parts of civilization right now.  (Oh, your house hasn't been flooded yet?  How about that cancelled trip to Blue-green-algae-land, Florida (https://floridadep.gov/AlgalBloom)?) 

What we do know (from this forum) is that there are many forcings that have not yet been fed into climate models because they are little understood or only recently discerned, and scientists have been shying from 'what's the worst that can happen, realistically'.   In a few years (next IPCC), a 4C future in my kid's life time may be painfully 'realistic'.  Lloyds of London is famous for insuring odd things (and making money doing so); I wonder what odds they are giving for "no 4C increase by 2065".  We're gambling with our future and most of us are placing all our bets on 'it can't be that bad'. 

Rboyd responded well, too.

Therefore, I sure hope scientists and engineers working on DAC find some nifty solutions, pronto!

Technically DAC is feasible today. Economically not so by a mile....
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Tor Bejnar on August 09, 2019, 10:18:37 PM
Thanks, DrTskoul, that's what I meant, economically and environmentally feasible DAC.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on August 09, 2019, 10:26:21 PM
Rboyd repsonds from the perspective that renewables can't compete with fossil fuels.  He hasn't kept up with the current economics. And AbruptSLR only posts studies that use the RCP8.5 emissions scenario, (other studies don't support his doomer conclusions), which is no longer possible because we aren't going to burn the amount of coal and oil that the RCP8.5 projected.

The clear facts are that the transition to a carbon free electricity generation and an electric vehicle future are well underway.  Insurers are no longer insuring coal infrastructure.  And now banks have realized that by the late 2020s oil is going to be unprofitable.

https://thinkprogress.org/oil-faces-irreversible-decline-thanks-to-electric-cars-and-solar-warns-worlds-8th-largest-bank-d128101ef4a8/ (https://thinkprogress.org/oil-faces-irreversible-decline-thanks-to-electric-cars-and-solar-warns-worlds-8th-largest-bank-d128101ef4a8/)

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Plunging prices for batteries and renewables are driving an electric vehicle (EV) revolution so rapidly that the economics of oil “are now in relentless and irreversible decline.”

That’s the startling conclusion of a detailed new analysis for “professional investors” of the economics of EVs versus gasoline cars produced by BNP Paribas, the world’s eighth largest bank by total assets.

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Lewis notes that many independent analyses — including Bloomberg New Energy Finance and the risk management firm DNV GL — have concluded that in the 2022-2024 timeframe, the total lifecycle cost of owning an EV will be cheaper than that of owning a gasoline-fueled car.

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But one of the most startling findings is that because the cost of running EVs on solar or wind power is dropping so rapidly, the only way gasoline cars can compete with these renewable energy-powered EVs in the 2020s is if the price of oil were to drop to $11 to $12 per barrel. The current price of oil is over $50.

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“By the late 2020s” Lewis explains, a significant fraction of the oil produced today “might only be competitive at a price below [oil companies’] full cost of production.” Even worse, this fraction “will rise over the lifetime of these projects as the penetration rate of EVs increases.”

If you can’t produce oil profitably at under $10 or $20 a barrel, your oil company is in big trouble.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: bluice on August 09, 2019, 10:31:25 PM
Given that coal is rapidly being phased out and replaced by renewables, the warming rate will be decreasing, not increasing, over the next few years.
Emissions are not being phased out. Fossil fuel use is increasing globally. As is to be expected, atmospheric CO2 level is also increasing. In fact the rate of increase is getting higher, above 3 ppm / year.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: wili on August 09, 2019, 10:37:53 PM
A 4C increase was seen as quite possible within this century already way back in 2011, when the Royal Academy devoted an entire volume of its journal to studies about what that would mean:

https://royalsocietypublishing.org/doi/full/10.1098/rsta.2010.0303

Things haven't gotten any better since then as far as the Keeling Curve goes, so I don't see how we can be confident about exactly when we will get there. Many others already many years ago claimed that 6C was possible or likely before the end of the century. And recently:

https://www.theguardian.com/environment/2009/nov/17/global-temperature-rise

Global temperatures could rise 6C by end of century, say scientists

Part of the 'scenario': 
Quote
...natural sinks are becoming less efficient, absorbing 55% of the carbon now, compared with 60% half a century ago
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: KiwiGriff on August 09, 2019, 10:59:39 PM
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what Brazil will be doing to the Amazon.

What we are doing to the Amazon.
If we hit 3C there is a good chance that the amazon region will transition from rain forest to  savannah.
This change will release much of the carbon contained in the present forest.
Not being all skyrockety the change  will  happen over century's not decades.
Earth system sensitivity is  higher than the usually quoted ECS equilibrium climate sensitivity.
Deforestation of the Amazon being one of the feed backs not addressed in ECS calculations.

Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: TerryM on August 10, 2019, 03:39:31 AM
When I hear of the US plotting the overthrow of solar optimized regions, or attempting to gain control of the best wind turbine sites, then I'll believe that fossil fuels have a less important future than renewables.


Madame Albright wouldn't have thought that the death of half a million Iraqi toddlers was "in the end worth it", if the upside was gaining access to Iraq's vast sun soaked deserts.

Terry
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Sebastian Jones on August 10, 2019, 07:10:07 AM
When I hear of the US plotting the overthrow of solar optimized regions, or attempting to gain control of the best wind turbine sites, then I'll believe that fossil fuels have a less important future than renewables.


Madame Albright wouldn't have thought that the death of half a million Iraqi toddlers was "in the end worth it", if the upside was gaining access to Iraq's vast sun soaked deserts.

Terry
An additional benefit of renewables is that they do not lend themselves to the economics of scarcity and therefore do not provide a very good vehicle for people or companies to get stinking rich. So, assuming we still have a global civilization after we transition to renewables, counties will be unlikely to battle over wind or sun sources. I hope Ken's optimism is not "hopium"!
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: TerryM on August 10, 2019, 07:42:23 AM
^^Ramen
Terry
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: nanning on August 10, 2019, 12:04:56 PM
<snip>
An additional benefit of renewables is that they do not lend themselves to the economics of scarcity

Well, they are very dependent on mined resources. All those rare earth metals have to be dug up.
Long term is a bitch.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Tor Bejnar on August 10, 2019, 03:03:42 PM
Well said, Nanning.  So a few mining companies will get 'stinking rich', but this doesn't hold a candle to the monopoly a few petroleum companies currently have.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on August 13, 2019, 10:58:39 PM
<snip>
An additional benefit of renewables is that they do not lend themselves to the economics of scarcity

Well, they are very dependent on mined resources. All those rare earth metals have to be dug up.
Long term is a bitch.

This is an incredibly persistent myth.  While some manufacturers still use rare earth minerals for wind turbines, they can be easily replaced with iron and copper.  That's why the price for rare earth minerals crashed pretty quickly after it spiked around 2010.

https://thebulletin.org/2017/05/clean-energy-and-rare-earths-why-not-to-worry/ (https://thebulletin.org/2017/05/clean-energy-and-rare-earths-why-not-to-worry/)

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Around 2010, many commentators stridently warned that China’s near-monopoly on supermagnet rare-earth elements could make the growing global shift to electric cars and wind turbines impossible—because their motors and generators, respectively, supposedly required supermagnets and hence rare earths. Some such reports persist even in 2017. But they’re nonsense. Everything that such permanent-magnet rotating machines do can also be done as well or better by two other kinds of motors that have no magnets but instead apply modern control software and power electronics made of silicon, the most abundant solid element on Earth.

The first kind is the induction motor, invented by Nikola Tesla 130 years ago and used in every Tesla electric car today. The second kind, less well-known despite origins tracing back to 1842, is the switched reluctance (SR) machine, likewise made of just iron and (less) copper, but using a different geometry and operating principle. If well-designed, which many are not, SR motors are simpler than permanent-magnet motors, more rugged (so they’re widely used, ironically, in mining equipment), more easily maintained, and equally light and compact. They can switch in milliseconds between serving as a motor or as a generator, and spinning in either direction. They’re also more flexibly controllable, more heat-tolerant, and cheaper for the same torque and production volume. The only scarce resources associated with such capable SR machines are familiarity, which few motor experts have, and skill in their more-difficult design—especially at the level achieved by the UK firm SR Drives (bought first by the US firm Emerson Electric, then by Japan’s Nidec).

Both kinds of magnet-free machines can do everything required not only in electric cars but also in wind turbines, functions often claimed to be impossible without tons of neodymium. That some wind turbines and manufacturers use rare-earth permanent-magnet generators does not mean others must. It’s better not to, and the word is spreading.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: Ken Feldman on August 14, 2019, 12:27:49 AM
A 4C increase was seen as quite possible within this century already way back in 2011, when the Royal Academy devoted an entire volume of its journal to studies about what that would mean:

https://royalsocietypublishing.org/doi/full/10.1098/rsta.2010.0303

Things haven't gotten any better since then as far as the Keeling Curve goes, so I don't see how we can be confident about exactly when we will get there. Many others already many years ago claimed that 6C was possible or likely before the end of the century. And recently:

https://www.theguardian.com/environment/2009/nov/17/global-temperature-rise

Global temperatures could rise 6C by end of century, say scientists

Part of the 'scenario': 
Quote
...natural sinks are becoming less efficient, absorbing 55% of the carbon now, compared with 60% half a century ago

Using the very unrealistic RCP 8.5 scenario (which assumes we continuing burning coal and oil until they run out), a 4C temperature increase would happen between the 2060s and the end of the century.

https://link.springer.com/article/10.1007/s00376-018-7160-4 (https://link.springer.com/article/10.1007/s00376-018-7160-4)

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Advances in Atmospheric Sciences

July 2018, Volume 35, Issue 7,  pp 757–770

Climate Change of 4°C Global Warming above Pre-industrial Levels

Authors

Xiaoxin Wang, Dabang Jiang, Xianmei Lang, Xiaoxin Wang

Abstract

Using a set of numerical experiments from 39 CMIP5 climate models, we project the emergence time for 4◦C global warming with respect to pre-industrial levels and associated climate changes under the RCP8.5 greenhouse gas concentration scenario. Results show that, according to the 39 models, the median year in which 4◦C global warming will occur is 2084. Based on the median results of models that project a 4◦C global warming by 2100, land areas will generally exhibit stronger warming than the oceans annually and seasonally, and the strongest enhancement occurs in the Arctic, with the exception of the summer season. Change signals for temperature go outside its natural internal variabilities globally, and the signal-tonoise ratio averages 9.6 for the annual mean and ranges from 6.3 to 7.2 for the seasonal mean over the globe, with the greatest values appearing at low latitudes because of low noise. Decreased precipitation generally occurs in the subtropics, whilst increased precipitation mainly appears at high latitudes. The precipitation changes in most of the high latitudes are greater than the background variability, and the global mean signal-to-noise ratio is 0.5 and ranges from 0.2 to 0.4 for the annual and seasonal means, respectively. Attention should be paid to limiting global warming to 1.5◦C, in which case temperature and precipitation will experience a far more moderate change than the natural internal variability. Large inter-model disagreement appears at high latitudes for temperature changes and at mid and low latitudes for precipitation changes. Overall, the intermodel consistency is better for temperature than for precipitation.

There are many studies about how we can limit temperature increases to less than 2C, and even 1.5C.  Here's one:

https://www.researchgate.net/publication/323564003_Scenarios_towards_limiting_global_mean_temperature_increase_below_15_C (https://www.researchgate.net/publication/323564003_Scenarios_towards_limiting_global_mean_temperature_increase_below_15_C)

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Rogelj, Joeri & Popp, Alexander & V. Calvin, Katherine & Luderer, Gunnar & Emmerling, Johannes & Gernaat, David & Fujimori, Shinichiro & Strefler, Jessica & Hasegawa, Tomoko & Marangoni, Giacomo & Krey, Volker & Kriegler, Elmar & Riahi, Keywan & Vuuren, Detlef & Doelman, Jonathan & Drouet, Laurent & Edmonds, Jae & Fricko, Oliver & Harmsen, J.H.M. & Tavoni, Massimo. (2018). Scenarios towards limiting global mean temperature increase below 1.5 °C. Nature Climate Change. 8. 10.1038/s41558-018-0091-3.


Abstract


The 2015 Paris Agreement calls for countries to pursue efforts to limit global-mean temperature rise to 1.5 °C. The transition pathways that can meet such a target have not, however, been extensively explored. Here we describe scenarios that limit end-of-century radiative forcing to 1.9 W/ m2, and consequently restrict median warming in the year 2100 to below 1.5 °C. We use six integrated assessment models and a simple climate model, under different socio-economic, technological and resource assumptions from five Shared Socio-economic Pathways (SSPs). Some, but not all, SSPs are amenable to pathways to 1.5 °C. Successful 1.9 W /m2 scenarios are characterized by a rapid shift away from traditional fossil-fuel use towards large-scale low-carbon energy supplies, reduced energy use, and carbon-dioxide removal. However, 1.9 W /m2 scenarios could not be achieved in several models under SSPs with strong inequalities, high baseline fossil-fuel use, or scattered short-term climate policy. Further research can help policy-makers to understand the real-world implications of these scenarios.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: petm on August 14, 2019, 12:40:20 AM
Using the very unrealistic RCP 8.5 scenario (which assumes we continuing burning coal and oil until they run out), a 4C temperature increase would happen between the 2060s and the end of the century.

That assumes the IPCC forecasts are accurate, which is unlikely given the reports are highly conservative and partly or completely omit important known positive feedbacks such as CH4 release from thermokarst lakes and ice-albedo feedback. I also don't think the RCP 8.5 emissions scenario is that unrealistic.
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: DrTskoul on August 14, 2019, 12:45:29 AM
Is there a better thread for the RCP. IPCC, expected max temperature rise etc ? This thread is for DAC...
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: KiwiGriff on August 14, 2019, 01:01:30 AM
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Successful 1.9 W /m2 scenarios are characterized by a rapid shift away from traditional fossil-fuel use towards large-scale low-carbon energy supplies, reduced energy use, and carbon-dioxide removal.
Not presently possible with current technology on the scale we need. AKA magic thinking.

Models in CMIP6 are suggesting an ECS between 2.8C  and 5.8C. This compares with the previous coupled model intercomparison project (CMIP5), which reported values between 2.1C to 4.7C.
If so we don't need to follow the 8.5 emissions pathway to be facing truly catastrophic consequences.

(https://pbs.twimg.com/media/D4bWVGfWwAEKcGx.jpg)
Title: Re: Direct Air Capture (of Carbon Dioxide)
Post by: DrTskoul on August 14, 2019, 02:42:47 AM
It's not a forcing thread... please refrain from OT