@hkuppy so my basic view is that ECO vs non ECO is 30 ton difference fuel per day VLCC. Numbers vary from sources but can be 38 vs 65 (average existing non ECO). The EU way of doing carbon is to hit the top emitting part. I think that is likely in shipping soon.

A carbon tax which even Trafigura says needs to be huge is most effective if it like in EU says it is free to emitt top in class amounts but you have to pay up on the top part.

So the most effective carbon tax would give a 2019 ship zero carbon cost (as it is currently the best on water emitting 38 ton) but hit a 2008 ship with very high tax on everything above 38 ton. The point is that everything I see is a willingness to put these taxes very high.

My thinking is that with 65% of the fleet non ECO and yard capacity of 5%, and not yet identified profitable new techniqe (you need the high carbon taxes first), it will take 13y from 2025 to get rid of non ECO. Post 2030 current eco start to be in the bad situation TNK is about