[moneytide1]

Perhaps your website could provide coordination with land owners to show which areas are eligible for tree planting. People could even use an app to designate which areas they intend to plant on, and mark as complete. New areas would be opened up as more municipalities (or private land owners) jump on board. There is already a federal effort for tree planting, as my family owns some hunting land that they are paid to keep trees growing (likely for local soil/water retention efforts)

This wouldn't be the first time people have banded together for "Emergency Conservation Work" (FDR administration 5 billion trees):

https://treesource.org/news/lands/ccc-tree-planting/

I've had decent success planting things after amending the soil where the rootball is expected to be. This involves removing some of the clay-like soil and replacing with both seasoned and fresh compost. Planting a trillion trees within a rather urgent window of time may not be eligible for this sort of micromanagement (plus the root system of a tree will be quite large), but I still like the idea of spending free time doing this sort of thing.