Do trees actually help? AFAIK once a forest reaches equilibrium it puts out as much CO2 as it takes in through various decomposition processes.
While a hectare of forest may be "only" CO2-neutral, a hectare of buildings are typically net CO2 emitters.
Of course this strategy does have to go hand-in-hand with drastic emission reductions to prevent use getting back to the same point and having nowhere else to put trees.
In the 2070s things will be very different.
Forests need to be managed to optimize for sequestration; log the right parts at the right time, replant. Also need to invest more in controlling forest fires (hell, use the military if that's the only way to get the budget).
At the other end we need to reduce burning wood for fuel through other renewables and put more lumber into building.