The options include restricting the amount of emissions units available; increasing the demand for units by allowing the government or foreigners to buy credits; creating two prices, one for reducing emissions and one for greenhouse gas removals like tree planting; or creating a whole new ETS market with separate incentives.
This is a companion discussion topic for the original entry at https://www.sciencemediacentre.co.nz/2023/06/19/reworking-the-emissions-trading-scheme-expert-reaction/