Response: Technology – capture and store CO2
CO2 pulled from the air – image: Climeworks
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Summary
The IPCC pathways assumed that technology would be invented ‘spontaneously’. The plan by 2050 was to slowly reduce fossil fuel emissions under a carbon budget that was entirely dependent on simultaneously removing 8 billion tons of CO2 every single year. In reality, only about 0.1% is being removed by technologies. To put this in perspective:
In 2022, the world emitted 40.5 billion tonnes of CO2. At that rate, for every year of operation at its full potential, each CDR [carbon dioxide removal] hub would take the atmosphere back in time by almost 13 minutes, but in the time it took to remove those 13 minutes of CO2, the world would have spewed another full year of CO2 into the atmosphere. If everyone on Earth planted a tree—8 billion trees—it would take us back in time by about 43 hours every year, once the trees had matured. Humanity has never removed an atmospheric pollutant at a global, continental or, even, regional scale—we have only ever shut down the source and let nature do the clearing up. – Prof. David Ho 2023
The carbon budget, created and monitored by Global Carbon Budget included how much CO2 was being emitted (‘spent’) and how much the planet was absorbing (‘saved’). The above calculation from David Ho is based on human caused emissions while assuming that the land and ocean would continue to ‘save’ CO2 as a constant rate. But in 2024, the land stopped absorbing about 30% of what previously had done, that was no longer the case due to collapsing ecosystems.
MIT breaks down the technical challenges using direct air capture (DAC) in this November 2024 paper. The other acronyms used are CCS (carbon capture & storage) to store CO2 back underground or in the ocean, permanently. Figure 1 summarises the range of processes.
Disingenuously some companies are capturing but not storing CO2. Instead, they’re selling it as fuel, returning the CO2 back into the atmosphere. Others do pump it underground, but around 70% is injected into depleted oil wells, to squeeze out the last few drops of oil, to keep us addicted to fossil fuels. (Video 1).
Don’t Fall for Big Oil’s Carbon Capture Deceptions: Carbon capture technology is a PR fig leaf designed to help Big Oil delay the phaseout of fossil fuels. – Scientific America 2023
…it can be concluded that less than 10mtpa of CO2 was injected in 2023 – or 0.00026% of global energy-related emissions last year. The promotion of CCS (carbon capture and storage) by the fossil fuel sector aims to maintain business as usual, not to reduce production of oil and gas, meaning emissions of this scale will continue into the future.– 2024 Eefa Institute
The safest way to store CO2 underground is in places where the CO2 is mineralized, that is, it becomes a rock. This is the process used by Carbfix in Iceland for DACC. Considerable research and experimentation is currently underway to find locations and/or other types of minerals that can be used to enhance this process. If places to store CO2 underground can be found close to factories that produce large amounts of CO2, then the cost of storing carbon safely in rock formations will become much more appealing. As with all things, there are likely to be trade-offs. For example, one kind of rock called olivine may help with this mineralisation process:
Our preliminary investigations have shown Mg can also be extracted from basalt; however, we will primarily focus our discussion on two enriched and accessible olivine deposits: the Semail ophiolite (Oman) and the Red Hills Ultramafic Complex (New Zealand) which conservatively contain 1.4 × 105 and 871 billion tonnes of olivine, respectively. – Scott et al (2021)
But Maungakura Red Hills near St Arnaud is part of the Mt Richmond Forest Reserve; it’s surrounded by native ecosystems (Figs. 2a & b). The whitish area in the centre of Fig. 2b is an ephemeral riverbed, not a road.
- CDRXIV is an online repository for preprint articles and datasets on carbon dioxide removal (CDR). It is free to submit content and free to use.
- Carbon Removal Updates provides a weekly summary of science papers and who is doing what in this sector.
- Statista shows the capacity of operational large-scale carbon capture and storage facilities worldwide as of 2024.
- CDR.fiy provides comprehensive analysis of current markets: “Buyers want proof of what they are getting.”
