Plant-based CO2 drawdown and storage as SiC

Abstract

Since the 1950's the Earth's natural carbon cycle has not sufficiently sequestrated excess atmospheric CO₂ contributed by human activities. CO₂ levels rose above 400 ppm in 2013 and are forecasted to exceed 500 ppm by 2070, a level last experienced during the Paleogene period 25–65 MYA. While humanity benefits from the extraction and combustion of carbon from Earth's crust, we have overlooked the impact on global climate change. Here, we present a strategy to mine atmospheric carbon to mitigate CO₂ emissions and create economically lucrative green products. We employ an artificial carbon cycle where agricultural plants capture CO₂ and the carbon is transformed into silicon carbide (SiC), a valuable commercial material. By carefully quantifying the process we show that 14% of plant-sequestered carbon is stored as SiC and estimate the scale needed for this process to have a global impact.