Untrue.
Just letting a forest grow wild is carbon neutral.
The soil reaches a point of saturation. Eventually the dead trees get eaten by detritivores, releasing the captured carbon back into the air.
Keeping it sequestered long term requires burying it deep - the trees would need to be cut down and transported to where bacteria, fungus, and so on can’t eat them.
This.
Also, look at the attic, check for roof leaks and adequate ventilation. Make sure your soffit vents aren’t clogged, and the soffit baffles and ridge vent have actually been installed properly.