You can plant more trees. You can't un-burn the coal that spins the motor. (I wonder if there's a way of actually comparing the environmental impact, though).
Planting trees sequesters the CO2 that was emitted from the burning of the coal. Cutting trees down and turning them into paper that easily decomposes hastens the release of the previously sequestered CO2 back into the atmosphere, killing us all.
Every time you use a paper towel, you kill a puppy.
Every time you use a paper towel, you kill a puppy.