Using Earth's Geology
Geologic storage of carbon dioxide is a critical component of negative emissions technologies. Underground geologic formations offer immense capacity for permanent storage of CO2. Natural interactions between the atmosphere and the Earth's surface also provide promising approaches to durable, large-scale carbon storage.
Enhancing Natural Processes
When CO2 interacts with rocks rich in calcium, iron, or magnesium, it can turn into rock through mineralization. Alternatively, CO2 can break up the surface metals and form a stable bicarbonate ion (HCO3-) in a process known as weathering. In either case, the CO2 is stored for tens of thousands of years, or even longer. Geologic processes like weathering and mineralization already draw down an estimated 1.1 billion MTCO2 a year. Under the right conditions, we can accelerate and scale these reactions to store additional gigatons of CO2.