Carbon Removal

Carbon removal is the process of drawing carbon dioxide out of the atmosphere so that it can be locked or sequestered into plants, soils, rocks, oceans and the built environment.

The purpose of carbon dioxide removal is to return atmospheric CO2 concentrations to safer levels and avert the worst of a rapidly changing climate. Concentrations are higher today than they have been in millions of years, currently sitting around 420 parts per million, and the risks associated with this are real.

Removing carbon from the atmosphere is crucial for several reasons:

Firstly, despite our best efforts to reduce emissions, there will always be some that are “hard to abate” and cannot be completely eliminated. Carbon removal technologies are essential in offsetting these residual emissions.

Secondly, achieving “net zero” – a state where all carbon emissions are counterbalanced by carbon removal methods – is impossible without these technologies. This is true whether we’re considering a single company, a community, or the entire world.

Lastly, the concentration of CO2 in the atmosphere has reached unprecedented levels. To restore a stable climate, we must not only reduce annual emissions but also lower the total CO2 concentrations in the atmosphere. Only then can we hope to slow and ultimately reverse the effects of climate change.

How can carbon be removed from the atmosphere?

In addition to natural processes that continuously remove some CO2 from the atmosphere, there are interesting options that can help us remove even more:

    • Direct Air Capture technologies use large fans that draw in air, which then undergoes a series of chemical reactions causing CO2 to separate from the rest of the air. The captured CO2 can be permanently stored in deep geological formations.
    • Mineralization or “enhanced weathering” is a method that accelerates the natural processes by which various minerals absorb CO2 from the atmosphere. Certain minerals inside rocks react with atmospheric CO2 to create carbonates, solid minerals that securely remove and sequester CO2.
    • Ocean Alkalinity Enhancement involves adding alkaline substances to seawater to enhance the ocean’s natural carbon sink. By increasing the alkalinity of the ocean, its capacity to absorb and store CO2 from the atmosphere is enhanced.
    • Biochar is a type of processed plant matter that is very rich in carbon. It is created when organic material is heated and pressurized in a zero or very low-oxygen environment. The carbon in the biomass gets converted to a stable form in biochar, which can stay locked in soil for many years. This method not only removes CO2 from the atmosphere but also improves soil health and food security.

Carbon Engineer’s DAC site in British Columbia. Image Source: Carbon Engineering