Supposedly; poplar trees are rapidly growing and as such are doing lots of breathing. With the leftist, it is not just CO2, it is also the oil industry...any thing to destroy America. Planting millions of trees means lots of water. The Eastern and Central Time Zones have got lots of trees...and lots of water. Wyoming...sad to say not so much...and therefore with little water; very few trees. The Plants in the lakes and oceans probably do more CO2/oxygen exchanging than do the trees on the surface.
That's because they have been brainwashed to be against CARBON. All forms of CARBON. That's why Al Gore wanted a CARBON TAX.