There's already a solution in the works...

https://www.smh.com.au/environment/climate-change/flatulent-...

For this to scale properly it would need to rely on creating a new market for seaweed farms with the purpose of sending to feedlots. I have a hard time imagining this actually happening.

Pricing it appropriately would be key, and a price on carbon emissions the obvious solution - and the market should respond.