Soils enriched with calcium could aid in the reduction of carbon gases through the “stimulation of plants’ natural carbon fixation process” ;

In most soils, that carbon returns to the atmosphere. But in calcium-rich soil, the acid, which contains carbon, reacts with the calcium by forming calcium carbonate deposits around the roots. Isotopic analyses have shown that this carbon-trapping is significant: it could reach 150 kg [330 lbs.] per year per hectare in a field of wheat.

The carbonates in the soil remain stable for very long periods and consequently constitute a virtually permanent geological carbon sink. “They could be used passively, the same way reed beds are used in lagoons to grab heavy metals out of polluted water,” according to David Manning, professor of geology at Newcastle University (United Kingdom).

Source:

• Le Monde Article by: Hervé Kempf, (translated to english)

If that does not work there is always the option of “genetically engineered carbon-eating trees.“