The study evaluated greenhouse gas emissions from lumber products at sawmills in Mie Prefecture, Japan. Using a life cycle assessment method, the average emissions per cubic meter of lumber were found to be 153kg-CO2e/m3. The emissions varied greatly among sawmills, with a range from 54kg-CO2e/m3 to 473kg-CO2e/m3. Factors like finishing processes for products and the type of heat source for artificial drying significantly influenced emissions. Interestingly, even if fossil fuels were used as a heat source, emissions could be reduced by scheduling artificial drying during hot summer months.