Monday, January 6, 2020

Zero carbon by 2050

If we want to stop catastrophic climate change and global heating, we need to cut emissions of CO2 and methane to zero by 2050.  Let's split those 30 years up into decades, aiming to cut emissions by 1/3rd of the 2019 level each decade.

2020-2030

This will be the decade where we have to close down as many coal power stations as we can.  The good news is that in most countries, wind or solar or both are now cheaper than (new) coal.  In developed countries, most coal power stations are old, and will soon have to be retired.  When they are, they will be replaced by wind and solar.  Even with 10 hours of storage, wind and solar are the cheapest power source in the USA, except for existing coal power stations which have been fully depreciated and have had their debt paid off.  But of course, they are precisely the power stations which will need to be retired over the next decade.

Even in China, where coal is cheap, large-scale solar will this year reach grid parity, meaning it can compete with the wholesale price of electricity, which is determined by China's massive coal fleet.  China produces 35% or world CO2 emissions, and is the largest consumer of coal.   A change here will be very important for world emissions and the global climate.

So the target is that by 2030, the number of coal power stations still operating will be small.  They'll simply be too costly to keep going.  This is much faster then even the relatively optimistic BNEF forecasts (they forecast just 25% from renewables by 2030).  Nevertheless, the cost curves as well as the increasing global panic about catastrophic climate change suggest this will be likely.

During this decade, we should also try to switch heating from gas/oil to electric, and we will start the switch to electric transport.  Of which more below.   Electricity and heat production contributes 25% of global CO2 emissions, so we'll need to find more areas to cut emissions by 1/3rd by 2030.



2030-2040

This will be the decade where we electrify transport.  Battery costs are falling by 20% compound per annum.  This means that we should cross the $100/kWh battery pack cost line by 2023, which will mean that the "sticker price" of EVs will be comparable to ICEVs.  Already, in China and India (where it is very important that the growth in demand for personal transport isn't satisfied by petrol cars) small, cheap EVs are available.   Once again, the twin pincers of public anxiety about climate change and the plunging cost of EVs will rapidly squeeze fossil fuels out of the market. Assuming EVs reach 100% of new car sales by 2030, then by 2040, almost all the emissions from road transport will have stopped, assuming a 10 year vehicle life, which is lower than what it is now, but government will likely want to accelerate the transition by banning polluting cars and lorries from town centres as well as buying back aging fossil fuel clunkers.

In developed countries, these emissions are about 1/3rd of total emissions.  In developing countries, they make up a smaller proportion on average, though the percentages vary widely.  But demand for cars is growing fast in developing countries, so a transition to EVs will prevent big rises in emissions from this sector.

It will also be the decade when we make cement production and iron & steel carbon-neutral.  We have the technologies to do this now, but these processes are still more expensive than making them the old way.  Expect carbon taxes or regulations, to force a shift.

Battery technology may well have advanced far enough that we will be able to fly long distance without using jetfuel.  Or we will have shifted to carbon-friendly jetfuel.  Or we'll be flying long distance by SpaceX's suborbital shuttle, fuelled by green methane, and short distance by electric planes.  Once again, carbon taxes will help shift air travel towards zero-carbon alternatives. 

Emissions from transport and industry (iron & steel, cement, chemicals, mostly) make up another third of global emissions.  By 2040, these will have stopped.  They'll have to.  Together with what will have been done in the 2020s, total emissions will have fallen by roughly 2/3rds, a compound rate of decline of 5.5% per annum.


2015.  Source: EPA


2040-2050

By 2040, emissions from electricity generation, transport, and industry will have fallen dramatically.  But there will remain some emissions, by far the most important being agriculture, land-use, land-clearing, etc.  There's no particular reason to wait until 2040 to deal with these.  We could start transitioning now.  After all, we have alternatives to meat.  And perhaps by 2030 or so, most ppl will be terrified enough of climate change to change their personal lifestyles.  But change here will be hard.  With electricity generation, the future is already happening now.  Renewables are simply cheaper.   With EVs that will soon be the case.  But with meat, we're asking people to change life-long habits.  It'll have to be done, it's just that politicians will postpone action as long as they can get away with it.  Once again, a carbon tax would help the shift.   If you think that the outrage generated by trying to get our economy to switch to green electricity was over the top, wait till you tell people they must eat less meat.  Yet, I have hope.  Synthetic meats are taking off.  Vegetarianism and veganism are rising trends.   And if meat substitutes taste just like the real thing but don't inflict dreadful cruelty on animals and have a huge negative effect on the environment, then why not?

2020-2050

In each decade, the necessary year-on-year percentage decline will increase, even though as a percent of the starting point, the decadal declines will be roughly the same.   If we cut emissions 1/3rd by 2030, then we have to cut emissions by 1/2 from 2030 to 2040.  And from 2040 to 2050 by 100%.  These seem to be large percentages, but they will only look like that because of previous successes.

Many of the shifts will begin before the decade I've selected for each of them, though I expect my selected decade will be when they reach their culmination.  If the transitions are sped up, maybe we can reach near-zero emissions by 2040, if we move in all sectors.  And if we start massive re-afforestation we might achieve negative emissions, and will for the first time in the last 200 years see falling atmospheric concentrations of greenhouse gases.  We must surely hope so.

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