What can we do?
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| Source: EPA Buildings includes heating buildings, transportation is all transportation, industry includes iron and steel and cement. Heat production can be electrified as can transportation. But that still leaves industry and agriculture. |
Think of the problem as comprising three baskets. They're not the same size in each country, but just for now think of them as 1/3rd of the problem each.
The first basket is electricity generation. We need to get rid of all fossil fuel generation. This is the most important basket because if we convert our system to 100% green electricity we can do most of the things in the other two baskets using carbon-free electricity, and so get to a zero-carbon economy. And this should be by far the easiest to do, because wind and solar are now much cheaper than coal and gas power stations, and in fact in many places, cheaper than the running costs of coal and gas. It might be possible to persuade developed countries to switch to renewables when renewables are more expensive than fossil fuels (ignoring the externalities of deaths and ill-health and rising global temperatures caused by burning fossil fuels) but it's hard to persuade poor countries to do that. But if renewables are cheaper than fossil fuels then poor countries won't reduce their standards of living by choosing renewables. They'll increase them. The task of transitioning electricity generation to renewables just got a lot easier.
However, to provide 100% renewables to the grid, we will need storage. Which brings me to the second basket: land transport. The key here is the cost of batteries. Battery costs are falling by 20% per annum, so it will take 3 years before they are below $100/kWh of storage, which is the level at which EVs have the same sticker price as petrol cars. So, 2021.
But the cost declines won't end in 2021. By 2025, at that rate of decline, batteries will cost $40/kWh. The cost of storage for 24 hours of electricity in the grid will be just $11/MWh, assuming a 10 year life. No one will build a new fossil fuel power plant and no one will use existing ones any more. Similarly, EVs (electric vehicles) will be a lot cheaper than ICEVs (internal combustion engined vehicles). EVs will make up 100% of car and light truck and prolly also bus and heavy truck sales. It will take a decade in developed countries and 15 years in developing countries for the vehicle fleet to transition to 100% electric. But by 2040, ICEVs will be available only in museums and at old-timer rallies.
So by 2040, both those baskets will be 100% green. Good news, even though the world will be o.4 degrees C warmer by then.
That leaves the third basket, which is a hodgepodge of lots of smaller emission sources. The two biggest are forest/bush clearing and burning and agriculture. Forest clearing could surely be stopped right now by appropriate international action, if we wanted it. A man-to-man talk with Brazil, Borneo, Indonesia and Australia would stop this source of emissions. Agriculture is a major source of emissions, but mostly of methane which is a far more potent greenhouse gas than CO2. Apparently cattle produce more methane from their burps than their farts. We could reduce emissions by 10-20% if we stopped eating meat and dairy. Fat chance with that: if we tell people that they have to eat less meat or vat meat and give up cheese, they will fall to the floor and start chewing the carpet. Still, it might have to be done, if we are to stop runaway global warming.
Then there's air transport. Batteries are still too heavy for planes. But meanwhile, we can produce carbon-friendly jetfuel using the Sabatier process. Replacing 5% of fossil fuel jetfuel each year with carbon-friendly jetfuel will lead to a small annual increase in air fares. Same thing with sea transport and diesel.
We're left with cement and iron and steel production. These sectors are harder, because to make iron we have reduce iron ore (i.e., iron oxide) to iron by heating it with coking/metallurgical coal which inevitably produces carbon dioxide. And we make cement by cooking limestone to drive off some of its carbonates, which also inevitably produces carbon dioxide. For these we will need some kind of carbon capture and storage, which turns CO2 into rock or uses it to strengthen cement.
To make changes in the last basket we will mostly likely have to have a carbon fee. The fee would start low and rise each year to minimise economic disruption. Its proceeds would be distributed to the population by way of a monthly "dividend" cheque. For example, a $20/tonne of CO2 emissions in the US or Australia, rising by $5 per year, would generate a "dividend" per person of $300 per annum; per family of 4 $1200 per annum in the first year. To avoid distorting effects on international trade, it would also apply to imports from countries which don't have a similar carbon fee.
I am very confident that by 2030 there will be very few working coal power stations left, and not many gas ones either. By 2040 there will be few ICEVs. But emissions in air travel, sea transport, agriculture and cement and iron and steel will remain unless something is done. And of course, the maths dictates that by then they won't be 20% of emissions but 90% plus. The pressure to do something about them will be intense.
I'm very optimistic that baskets one and two will shift, because of economics. But the contents of basket three will require a carbon tax and tighter regulations. And there, I'm much more pessimistic. Yet the logic is inexorable. We have to get to zero emissions by 2050 or face catastrophe. And that means emissions must fall by a compound 14% per annum. We're nowhere near that; in fact emissions are still rising. Is our species intelligent enough to save itself or not?
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