But does it help worrying about where we're putting logs while we're burning fossil fuels? We need to plant enough trees to offset all the trees we're burning, but also all the gasoline, oil, and natural gas we're burning as well as all the concrete we're producing. The math seems like it'll never balance.

I did the back of the napkin math below: https://news.ycombinator.com/item?id=42697255

Barring mistakes, it balances if we had avoided reducing the planet's vegetation by 20% since 1900. So much for that.

That's obviously not "the" solution, but it seems like reducing fuel burn while increasing forestation would benefit us beyond what is commonly expected.

Interesting math, so it is mathematically possible. Important to note, 1 billion hectares is just over the size of all of the United States.