Carbon Capture and Storage (CCS) for Climate Mitigation?

04 Aug 2019

Read on Twitter:

CCS not viable to solve climate change

#CCS is not viable to solve climate change.

The letter of in @FT argues it would nevertheless, because:

“the current policy pathway — maximising the development of renewable electricity — is unlikely to get us to net zero by 2050”


Why is this false?

“The energy needed to run direct air capture machines in 2100 is up to 300 EJ each year. This is more than half of overall global demand today, from all sources, and despite rising demand this century, it would still be 1/4 of expected demand in 2100.”

So, this is a double lock-in. No need to dig further into complicated integrated assessment, we need to decarbonise our industrial system as fast as possible first.

No surprise @snam, @exxonmobil, @Shell and others still try to make policymakers believe it would be of help.

@snam @exxonmobil @Shell Two recent articles go further in depth:

@SimonLLewis article in the @guardian

“We might think that negative emissions means that climate change can be tackled. But evidence that these technologies can work at a small demonstration scale is causing the opposite”

“Negative emissions are treated as a “get out of jail free” card – a licence to keep emitting and clean up the mess later with new technologies. Politicians and their advisers love them, because they can announce a target such as 1.5C while planning to exceed it”

“A future where carbon is scrubbed from the atmosphere is also manna from heaven for the enemies of a rapid transition away from fossil fuels. The greater the negative emissions, the less decarbonisation is needed.”

“@shell, for example, is rolling out a scheme this autumn for UK drivers to pay an extra 1p per litre on their petrol to have this global corporation plant a tree to convince motorists that they can “drive neutral” using “natural climate solutions”. “

“Scrutinise the pathways in the recent @IPCC_CH IPCC report consistent with the 1.5C target and the stated amount of negative emissions envisaged is incredible. Most scenarios have more than 730bn tonnes of carbon dioxide sequestered as negative emissions this century.”

“That is equivalent to all the carbon dioxide emitted since the industrial revolution by the US, the UK, Germany and China combined. There just isn’t enough land to suck up that much carbon into new forests.”

More on that:

“Using BECCS to remove this much carbon, as most scenarios assume, would require an area of new cropland larger than India, plus building a facility to store 1m tonnes of carbon a year every single day from 2025 to 2050. Negative emissions at this scale are the stuff of fantasy.”

@DrSimEvans article in @CarbonBrief on recent direct air capture and storage study

“Policymakers should not see direct air capture and storage (DACCS) as a “panacea” that can replace immediate efforts to cut emissions. “The risks of that are too high.” “

It distinguishes between bioenergy with carbon capture and storage (BECCS) - biomass, such as wood pellets, is burned to generate electricity and the resulting CO2 is captured and stored - and direct air carbon capture and storage (DACCS).

Bioenergy with carbon capture and storage (BECCS)

BECCS : ‘land areas up to five times the size of India devoted to growing the biomass needed in some model pathways’

Direct air capture and storage (DACCS)

“Committing to ramping up DAC rather than cutting emissions could mean locking the energy system into fossil fuels, the authors warn. This could risk breaching the Paris temperature limits”

“The risk of assuming that DACCS can be deployed at scale, and finding it to be subsequently unavailable, leads to a global temperature overshoot of up to 0.8C.”

“Inappropriate interpretations would be that DAC is a panacea and that we should ease near-term mitigation efforts”

“The global carbon cycle poses one final – and underappreciated – challenge to the large-scale use of negative emissions technologies such as DAC: ocean rebound. This is because the amount of CO2 in the world’s oceans and atmosphere is in a dynamic and constantly shifting equil.’

“At present, oceans absorb a significant proportion of human-caused CO2 emissions each year, reducing the amount staying in the atmosphere. If DAC is used to turn global emissions net-negative, as in today’s study, then that equilibrium will also go into reverse.”

“As much as a fifth of the CO2 removed using DAC or other negative emissions technologies could be offset by the oceans releasing CO2 back into the atmosphere, reducing their supposed efficacy.”