3 ms·

I thought iron and possibly phosphorus were already known to be very promising for this idea?

• neltnerb 5y ago
  I can't tell you whether the below is accurate, but this was why they said it is novel. ‘Tephra is cheap, not limiting, and all the required tech already exists. Bentonites – altered tephra – are already regularly mined, so we don’t need to develop new approaches,’ Longman says, adding that tephra would only require sieving in preparation for use. This, he added, ‘is unlike other ocean fertilisation approaches, which use processed iron oxide liquids.’
• blacksqr 5y ago
  The chief problem with iron seeding is that it is one of many nutrients required. It may be the one most needed, but stimulating growth by supplying just iron depletes the ocean of the other needed nutrients, so you stimulate growth in the seeded area and depress it elsewhere. Seeding with volcanic ash provides a fuller range of required nutrients.