True, that could happen. But if these people are planting gardens and food forests to literally provide food for their families, the interests align to keep those trees growing (and replanting any that die off for any reason). That, along with the longevity of the non-profit, makes it a reasonable-enough risk for me.
It would be cool if there were an organization (non- or for-profit) that would get you annual (or quarterly) reports on how their carbon capture is going. Perhaps through drone fly-overs, with software to capture the 3D image changes and then calculate/estimate the carbon mass storage increase/decrease.
It seems like a “debt” you take on. Today I will produce N carbon and plant enough trees to consume N carbon over 10 years. However, you aren’t actually watching the carbon repayment over 10 years. You’re trusting someone to do it for you. It seems like an easy swindle with how little regulations there are in this space.