No doubt, CO2 , a principle gaseous component for global warming, is absorbed through photosynthesis by plants. Simultaneously, the plants too, like any other animals, let out substantial CO2 especially at night.
I believe that global warming can not be solved by reforestation alone. Other human actions are needed, such as reducing the use of fossil fuels and chemical fertilizers.
In addition, depending on the objectives of the reforestation, the carbon and other elements stored in the wood can return to the atmosphere after the burning of charcoal and firewood. Another fact is that forests capture a large amount of carbon in their growth phase, when they reach a more advanced stage this process is reduced, through physiological processes and the decomposition of organic matter in forests, carbon returns to its cycle.