Over the years after concrete is put into service, it gradually absorbs CO2 from the atmosphere, approaching an asymptote where it eventually takes up about half as much CO2 as it emitted as process emissions from limestone calcination when the cement was made. This effect is significant but is often excluded from emissions inventories.
We should track concrete/cement carbonation uptake of CO2. This requires knowing how much cement is made each year and how much was made in years prior to the start of the model run.
In graphs, these CO2 negative emissions could be credited against the cement industry's emissions, but we would need to make sure all industry emissions graphs disaggregated by industry can handle negative emissions from the cement industry and still look correct. It should be fine, since Todd built support for mixed sign stacked area graphs into the web app. Or alternatively, if we want clarity about how much CO2 the cement industry is still emitting (and to better match emissions inventories), the abatement from cement carbonation could be added to the existing and seldom-used "georngineering" sector, since it is a form of carbon dioxide removal (CDR) that is not based on growing biomass/forests, like Direct Air Capture. Any preferences on these options regarding how to classify the sequestration in our output graphs?
Over the years after concrete is put into service, it gradually absorbs CO2 from the atmosphere, approaching an asymptote where it eventually takes up about half as much CO2 as it emitted as process emissions from limestone calcination when the cement was made. This effect is significant but is often excluded from emissions inventories.
We should track concrete/cement carbonation uptake of CO2. This requires knowing how much cement is made each year and how much was made in years prior to the start of the model run.
In graphs, these CO2 negative emissions could be credited against the cement industry's emissions, but we would need to make sure all industry emissions graphs disaggregated by industry can handle negative emissions from the cement industry and still look correct. It should be fine, since Todd built support for mixed sign stacked area graphs into the web app. Or alternatively, if we want clarity about how much CO2 the cement industry is still emitting (and to better match emissions inventories), the abatement from cement carbonation could be added to the existing and seldom-used "georngineering" sector, since it is a form of carbon dioxide removal (CDR) that is not based on growing biomass/forests, like Direct Air Capture. Any preferences on these options regarding how to classify the sequestration in our output graphs?