Large-scale tree planting can remove some CO2 from the atmosphere, but nowhere near as much as humans add by extracting and burning fossil fuels. See https://skepticalscience.com/1-trillion-trees-impact.html for a detailed assessment of what this looks like.
The IPCC has a chart showing what actions need to be taken over the next few years. Afforestation is one piece of many things, all of which we need to do.
It would take much longer for the trees to become effective carbon capture utilities than the destruction caused by coal mines and fossil fuels the Rs would likely push alongside their newfound climate wisdom.
Hybrid willows and poplars grow about 8ft per year in ideal conditions.