Storing it safely underground is one approach. What else could be done?
Total global CO2 emissions are currently more than 32 gigatonnes a year. For carbon capture technologies to play a meaningful role in the fight against climate change you need to capture and store, or find innovative ways to use, at least a few gigatonnes each year.
Captured carbon needs to be economically recycled into commercially viable products – such as calcium carbonate for making cement – as an alternative to carbon storage.
The cost of electricity is already 3 cents/kilowatt hour (kWh) in regions with good sun and wind resources, and many people believe costs could fall to 2/kWh in 10-years’ time.
Such cheap electricity opens the possibility of using electrochemistry to recycle the products of fossil fuel combustion – reducing the CO2 into carbon monoxide and hydrogen and splitting the water into hydrogen and oxygen.
Could chemical batteries play a bigger role, such as for storing excess renewable power?
Chemical batteries are still expensive. Prices are coming down dramatically because of mass production, but I don’t see the price of battery storage going significantly below $100/kWh within the next decade, or even longer.
You probably would need something like $10/kWh to make batteries a widespread solution for seasonal storage. Tesla’s new lithium-ion battery in Australia has roughly 100 megawatts (MW) of capacity, making it by far the largest in the world.
But it’s still only a very small fraction of what is needed. For example, in Texas, electricity demand on hot summer days can reach 80,000 MW.
What role could carbon pricing play in reducing emissions? How could governments approach it?
I used to be agnostic on whether we should take the emissions cap-and-trade approach or the carbon tax route, but now I’m more in favour of a carbon tax.
The reason is Europe started and operates a cap-and-trade system but the emissions price collapsed before long, in large part because there were too many credits given out.
Policy makers need great courage to reduce the number of allowances, year by year, because there’s so much pressure from various interested parties.
For carbon-pricing mechanisms to have a significant impact on emissions, governments need some way of arriving at a meaningful cost on carbon. By meaningful, I mean about $60-70/tonne of CO2 within the next couple of decades.
You can’t suddenly do that, but over two decades getting to $70/tonne will give industry plenty of time to prepare.
A carbon tax that rises in a predictable way would give certainty, and businesses always say they want certainty.
Can an effective global mechanism for pricing emissions be developed without US involvement?
I had been hoping that the governments of the USA, China and Europe could work together to co-ordinate their carbon pricing systems.
Carbon pricing is not something that you can negotiate in the United Nations.
It’s something where a bunch of sincere partners get together and the rest of the countries either join in or face carbon-price adjustments at trade borders.
That would prevent the countries who are moving forward on this from being economically penalised.
But now one of the major players, the USA, doesn’t appear to want to do this, certainly for the next few years.
It’s now a question of whether Europe and China can develop effective carbon-pricing mechanisms without the USA.