[alexose]

Note that most of the carbon offsets offered by airlines are forestry-related. Any time you see offsets for less than $50/ton, proceed with an abundance of caution.

I do think the general state of offsets is improving. There are more high-quality offsets hitting the market every day. They're much too expensive, but I'd rather see "real" offsets at a high price than the complete make-believe we've had up until recently.

[photochemsyn]

The only mechanisms at the CDR Database that look like actual long-term offsets are in the mineralization category, meaning the production of carbonate rocks from atmospheric CO2. The problem is you need the counterion to make these rocks, i.e. calcium or magnesium, and these are often already locked up in rocks. Mine tailings have been proposed as a source, I don't know.

https://en.wikipedia.org/wiki/Carbonate_rock

The sci-fi approach that would be great is pulling atmospheric CO2 out of the air and making diamond from it. The technology is sort of there already but the costs are ludicrous. The pathway is atmospheric CO2 + water -> methane -> synthetic diamond production. That last is a slow energy-intensive process, but such diamonds would be easily distinguishable from the 'real' geologic diamonds (as they'd have the same amount of carbon-14 as the atmospheric CO2 does). Worth someone writing a business plan I think.

[etrautmann]

Can you provide links? I’m very curious to learn more about real offsets even if expensive.

[alexose]

Sure! I usually point people at Carbonplan's CDR database: https://carbonplan.org/research/cdr-database

[mistrial9]

good on them to provide reproducible parts here; interesting to see the research trends of [json|csv] , [python|R] consistently..

[etrautmann]

Thanks! +1 to Carbonplan

[danielfoster]

Not sure what airlines are offering now, but when I checked in 2019, United’s offset scheme included funding for sustainable tourism and education in developing countries. Great causes, but not an offset.