It would've made sense if it was a true offset, i.e. carbon capture in various forms. But "offsetting" carbon-positive activity with carbon-neutral is just bizarre. Where is my money for sitting on a couch instead of taking a plane to Australia?
That would be hard to sell. Trees actually pull CO2 out of the air and lock it away in wood fibers. That produces an actual (albeit infinitesimal) reduction in the net atmospheric CO2.
Choosing to not take a flight to Australia, on the other hand, is just deciding to produce CO2, just less. That makes it categorically different, as it can't negate any amount of CO2 production.
Also, the supply of "not flying to Australia" is unbounded, and without scarcity, the price will naturally go to $0. If you only focus on potential fliers, that would have the perverse effect of incentivizing people to take actions intended to convince the regulators of this market that they were planning on flying to Australia, which would likely result in empty seats on flights to Australia and a net increase in the number of chartered flights to Australia.
In addition to mature forests being carbon neutral, not negative, the scheme in question has exactly the same problem you described - the supply of "not cutting trees" is huge if not unbounded, and it has very little to do with CO2 in the atmosphere.
trees pull CO2 out of the air, so planting more trees is carbon-negative. but how is just allowing the trees that are already there to continue existing carbon-negative? it can't be less CO2 that the status quo if it's literally the status quo.
Perhaps there are methods to maximize forest yield, it would probably be appropriate to bake that into the value I would think. I think forests that burn may leave behind char in the soil layers and on small time scales it would be insignificant but maybe it becomes significant over millennia?
