But even just considering carbon emissions, which have reduced in intensity
Anyone have a source to support that claim? It sounds like something that could be true on a per-capita basis, at least in “developed countries” over a cherry-picked time interval.
Properly scaled up, this type of community reforestation effort could work.
Lychee can grow at tropical latitudes, but it needs hot (rainier) summers and (drier) winters w/ 50-150 hours at 0-12°C in order to fruit well, so it’s more of a subtropical fruit.