Wood pellets are considered an environment-friendly biofuel. Forests can be managed so that trees become a steady, renewable source of energy unlike petroleum, which is a finite resource. In the end, carbon dioxide (CO2) emissions are lower, a key reason for the eco-friendly label.

In recent years, with the price of timber at a low and the aging of forestry workers in Japan, the number of cultivated forests that have become unmanageable has been on the rise. To maintain the health of conifer forests such as Cryptomeria or Hinoki cypress, and to allow trees to grow straight, bent or weak trees need to be culled to leave space between trees and allow light in to the forest. How to effectively use the timber felled in the thinning process is a critical issue. Creating wood pellets is an important solution. Also, forests can be replanted to ensure that they remain viable, continuing on as renewable resources.
Wood pellets are thus a renewable fuel and source of energy that protects the health of forests.

Have you ever heard of "carbon offsets"? When CO2 emissions are offset by an equivalent amount sequestered, resulting in a net zero carbon footprint, that is carbon neutrality.
With petroleum and other fossil fuels, the more that is used, the more CO2 is released into the atmosphere. Burning wood pellets also releases CO2, but as a biomass fuel the source is plant-based and renewable, which means that when trees are growing they sequester CO2 through photosynthesis, so the total amount of CO2 does not increase.
Also, if wood from the thinning of forests is used locally, CO2 emissions in transportation are also reduced.