dpm59 t1_j9hx65f wrote on February 22, 2023 at 2:21 AM

Reply to comment by zosolm in MIT team makes a case for direct carbon capture from seawater, not air by MotorDrive

The CO2 in the atmosphere is minuscule compared to the total CO2 in the oceans. So if you are taking CO2 from the oceans and believe that removing a tiny time percentage will some how magically lower atmospheric levels of CO2, I think you are wrong. Please keep in mind man’s scientific understanding of the total CO2 cycle is surprisingly poor. 95% of total CO2 released into the atmosphere is done naturally with the CO2 cycle. Please tell me who can accurately measure the natural sources of CO2 with a greater degree of certainty of +- 5%?

zosolm t1_j9j1ugh wrote on February 22, 2023 at 9:14 AM

As atmospheric carbon concentrations rise, carbon dioxide begins to dissolve into seawater. The ocean currently soaks up some 30-40% of all humanity's annual carbon emissions, and maintains a constant free exchange with the air. Suck the carbon out of the seawater, and it'll suck more out of the air to re-balance the concentrations.

K30 is a CO2 sensor which has 3% error bars, NDIR is another which is accurate to 0.005%. What is it we don’t understand about the carbon cycle? I learned it in high school. What does it mean that 95% of CO2 is done naturally with the CO2 cycle?

Edit: i understand what you meant now about 95% of CO2 is done naturally; it’s that thing of 95% of atmospheric CO2 comes from natural sources. So while that’s true in a way, it misunderstands the nature of the carbon cycle; decomposing and composting organisms, fires and all kinds of other natural processes do release carbon, but it’s carbon that was captured from the atmosphere by the growth of those organisms in the first place so there’s no net increase of carbon in the system. They do cycle through a lot of carbon, but they also take a lot up too when stuff grows. As for volcanoes, human activity releases 60-100 times more carbon than volcanoes. One of the problems with coal and oil is that it’s not part of the carbon cycle until we burn it so it’s disrupting that system by adding more carbon into it. In order to mitigate that, we need technologies that can capture what we’ve put out otherwise we’ll have to deal with the impact of there being more carbon in the system now than before we got all the oil out

dpm59 t1_j9j65uj wrote on February 22, 2023 at 10:15 AM

My comment about the lack of understanding of the carbon cycle refers more to the quantification of the natural sources of CO2 in the carbon cycle. The assumption is that before the Industrial age the cycle was in balance and man disrupted that. While this may indeed be true. ( but we have been warming since the last ice age) If the scientific community can not accurately quantify the natural release and absorption of CO2 it remains a hypothesis.

I have yet to find any accurate data on the natural sources with less than 5-10% accuracy. My personal opinion is that if more time was spent understanding the natural sources they also could be mitigated and possible more cost effectively.

Fundamentally I am against condemning man, which to be fair had made incredible progress lowering CO2 emissions on a productivity based over the past 100 years. Think about the progress moving from Wood to Coal to Oil to natural gas to nuclear, wind, solar, battery storage etc. Burning stuff enabled mankind, it is the differentiator between us and other living things. Without fire we wouldn’t excite today nor would any of our technology.

zosolm t1_j9jb4yu wrote on February 22, 2023 at 11:20 AM

Sure, I basically agree that condemning is pointless and am not interested in condemning anyone. That’s not what climate science is about. I guess that’s maybe more what happens in the political spheres? Idk

Just regarding the 5-10% accuracy thing (and without meaning to nitpick, just explaining what assumption I’m making from what you said); I guess you meant more than 5-10% accuracy because if you’re yet to find data with less than 5-10% accuracy that means you’ve only found data that’s more accurate than that.

If you’ve not found data that’s more accurate than 5-10% you might want to check again. The CO2 analyzer that was installed at Mauna Loa (an active volcano) uses a technique called Cavity Ring-Down Spectroscopy (CRDS). (Prior to this, an analyzer was used based on infrared absorption). CDRS I think is about 99% accurate and infrared absorption I am not too certain of but I’m sure it’s more than 5-10%.

They measure the amount of CO2 in the atmosphere. It doesn’t really matter if it’s coming from humans or not (incidentally, some of it is, but that’s irrelevant). The point is that we know the effect of more CO2 in the system is that the planet warms, and having modelled that we understand that’s going to cause problems for us. There’s things we can do about it like carbon capture and switching from fossil fuels. Which is cool.