Well it is a hypothesis that needs testing…

You are asking two how to questions “combat climate change” and “reduce emissions”

To realistically combat climate change:

• Admit that we need to try geoengineering (we are already doing this with all the CO₂ and CH₄ going into the atmosphere)
• Weather it is SO₂ injection or cloud seeding to artificially increase the albido; we need to reduce incident solar radiation to give us a few more decades to actually reduce emissions

To reduce emissions:

• Tackle the biggest emissions first.
• Electrification of the passenger fleet; that means batteries. Keep fuel cells for heavy transport (maybe)
• Encourage electric biking. And other micro-mobility. Along with better public transport.
• Normalise a historical style diet, meat is a treat only once or twice a week.
• Reduce concrete construction; keep it for the important things like the foundations.
• Reduce the practice of packaging everything in plastic; again keep it for the important things only like electrical insulation.
• Massive ramp up of solar and wind around the world.
• Where we use fossil fuels, ask is this important enough to use FF here?

Carbon taxes:

• Tax CO₂e (carbon dioxide equivalent) at a reasonable rate to encourage all of the reduction measures.
• At less than $65NZD/T the cost is too low to encourage significant movement on the issues.
• Have a ratcheting scheme in the CO₂ market, i.e. add $5-8/yr/T for CO₂e; in 10 years the price will be between $110-140/T. At the 10yr mark, make the ratchet $10-15/yr/T.
• Add a carbon tariff; basically make it more expensive to buy from countries that are not pulling their weight.
• Be careful not to double tax, this is important for buy in from the public. i.e. the carbon tax on fuel should be exempt from sales tax, taxing a tax is a great way to alienate people.