[simonebrunozzi]

You're missing an important detail: forests don't capture CO2 just once (in the form of organic matter, e.g. wood); they also capture it continuously... Slowly turning CO2 into coal/oil over millions of years, which is not included in the count for CO2 in forests.

It's instead like a slow by-product of it; as if we had "fossil forests" underneath live ones, which several gigatons of additional sequestered carbon.

Doubling the size of forests on Earth would provide benefits that go beyond the simple, one-time CO2 capture you refer to.