We focus our efforts on carbon dioxide (CO2), because this greenhouse gas is by far the largest contributor to climate change: it is estimated that CO2 is accounting for almost 66% of the warming effect on the climate. Mainly due to fossil fuel combustion and cement production.
Removing other greenhouse gases, such as methane (CH4), nitrous oxide (N2O) or fluorinated gases would require a fundamentally different technology partially because their concentrations are much lower than the concentration of CO2 in the atmosphere.