this post was submitted on 17 Jun 2023
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Carbon Dioxide Removal (CDR)
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CDR is removal of CO2 from the atmosphere - an essential basket of technologies for achieving UN IPCC best outcomes to mitigate climate change. This is a community for discussing advances and issues of CDR.
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It can highlight an interesting aspect of the problem though - its magnitude. Let's say the ten largest whale species' each number around 100k individuals, grow to an average of 50 tons, and live an average of 50 years - that is a pretty rough estimate, but reasonably consistent with an IWC webpage I checked. Most living things tend to have about 40% carbon by weight -give or take a few %. 10 species x 100,000 individuals/species x 50 tons x 40% / 50 years = 400,000 tons per year of carbon sinking to the bottom of the sea as whale carcasses.
The current rate of worldwide CO2 emissions is around 40 gigatonnes per year, and the excess carbon dioxide emissions from the age of fossil fuels is now up to about 1000 gigatonnes per year. But wait, that is not pure carbon! CO2 is only 27% carbon by weight. So world emissions per year: 11 Gt of carbon, accumulated excess carbon: 273 Gt. For convenience I will assume the tons of whales are tonnes (metric tons, or 1000 kg). So the annual whale-fall is 0.4 megaton/11 Gt/year or a mere 1.3% of ONE DAY of human emissions - a little over 19 minutes; or we could say we collectively emit enough CO2 every 19 minutes to make a whale? We're going to need a LOT of whales to get rid of all that CO2.
Of course, who doesn't want to have healthier ocean ecosystems? I am all for whales!
That is not the only argument made in the article thou. Whales increase photosynthesis by shitting out nutrients. This binds a lot more carbon.
I did see that, but the article seemed to want it both ways: the nutrients are there to feed the krill, but they are all the way down to the abyss where they'll never decompose before they become sediment carbon (sequestered). It cannot be both I think, and I don't know which is prevalent, so did not try to calculate. But I was in the Navy briefly, and the phrase "lower than whale shit" has never been forgotten . . .
Any process that sinks carbon to below 2000 feet has basically removed it from the atmosphere for at least several centuries. There is a whole area of documentation of carbon disposal arising called MRV (Measurement, Reporting and Verification) - when they start certifying whale shit, we will know that bureaucracy has fully permeated the planet.