Carbon Capture
What is Direct-Air-Capture (DAC)?
It is the process of Capturing atmospheric carbon dioxide using technology
and putting it away for thousands or if possible millions of years or utilize it to produce materials for a greener planet
Why do we need to remove carbon dioxide from the atmosphere?
More than 95% of the carbon dioxide levels that would push the world towards dangerous effects of climate change is already in the atmosphere.
Carbon dioxide is a greenhouse gas and the increase of its concentration in the atmosphere leads to increase in the temperature of the earth.
A warming of even 1.5 degrees over the preindustrial levels will result in large-scale drought, famine, heat stress, species die-off, loss of entire ecosystems, and loss of habitable land, throwing more than 100 million into poverty.
Every year we emit approximately 40 Gigatons of carbon dioxide into the atmosphere and removing hardly any. As per IPCC special report we have to remove 100-1000 Gigatons of Carbon Dioxide form the atmosphere in this century.
To prevent the worst effect of climate change we must not only reduce emissions at the source but also scrub accumulating carbon dioxide from the atmosphere as emissions at the source cannot be reduced to zero due to technological and other limitations. Also, for historic emissions there are no other options other than removing them directly from the atmosphere.
Reduction
Reduction is done at the source. The reporting company can take necessary steps at their end by adopting technological and other measures.
E.g. (1) A company replaces all diesel powered vehicles in the company to electric. (2) A cement manufacturer deploys CCUS to reduce emissions by 15%.
There is a limit to the reduction of emissions from a point source. Emissions for any source cannot be reduced to zero due to technical or other limitations.
Removal
Since emissions cannot be reduced to zero due to technological or other limitations, removal comes into the picture. Without removing emissions from the picture, net-zero is impossible.
Emissions that cannot be reduced at the source, like residual emissions, difficult-to-reduce, unavoidable, and historic emissions, need to be removed. The process requires carbon dioxide to be scrubbed from the atmosphere using technologically or by natural means.
Removal is generally sourced and is independent of the source and its location as it is the same atmosphere everywhere.
Our path to net-zero involves reducing whatever is possible at the source and then removing whatever residual, unavoidable, hard-to-reduce and historic emissions, that could not be reduced at the source.
Why only planting trees will not solve the climate problem?
● Afforestation cannot be scaled indefinitely as it has huge land & water footprint;
● Afforestation will affect arable land & hence food production
● The process is Slow; takes 10 yrs minimum to start & time is not on our side!
● Not Completely Measurable & Certifiable
● No guarantee of permanence
To get an idea about the kind of land footprint required to remove a gigaton of carbon dioxide with afforestation we should be surprised to know that removing 1 Gigaton of CO2 from the atmosphere by planting trees will require an area of twice the size of the State of California in the United States.
Then should we develop and deploy only Carbon Dioxide Removal (CDR) technologies like Direct-Air-Capture (DAC)?
NO is the answer. Why?
It is no more necessary to mention that time is no on our side. We must be quick and that is one of the reason why Direct-Air-Capture (DAC) comes into the picture. But, the key factor limiting DAC deployment is the rate at which it can be scaled up. In the existing scenario, average DACCS scale-up rates of 1.5 GtCO2/yr would require considerable sorbent production and up to 300 EJ/yr of energy input by 2100. 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 0.8 °C. DACCS should therefore be developed and deployed alongside, rather than instead of, other mitigation options [1].
That is why we have created the Novoton!
[1] Realmonte, G., Drouet, L., Gambhir, A. et al. An inter-model assessment of the role of direct air capture in deep mitigation pathways. Nat Commun 10, 3277 (2019).