Doesn't the same amount of carbon stays locked the same in a tree in the ground? I don't understand why building with wood helps in this case. There's plenty of space to grow more trees...
There's not an infinite amount of space to grow trees actually. A decent forest needs the right climate, water. Economically forestry must compete with other land uses such as grazing, orchardry, etc.
It takes pinus radiata about 25 years to reach maturity. Then it can be turned into buildings/ houses, and the carbon locked up in that structure, which can be e.g in the city or suburbs- somewhere there will never be suitable for forestry.
And then the forest can be replanted and the virtuous cycle begins again.
tldr; locking carbon up in timber gives more flexibility than just relying on standing forests.
