Increasing emission of greenhouse gases, mainly carbon dioxide, and reduced capacity of carbon sequestration due to excessive deforestation are the dominant reasons for the observed climate warming. Wood and wood products are inherent parts of the overall carbon “jigsaw puzzle”. Wood products require much lower process energy and result in lower carbon emission than non-wood products. Therefore, the prolonging lifespan of wood products seems to be a good economical and environmentally friendly solution. The aim of the research was to determine the effectiveness of wood treatment with aminosilane, caffeine and the mixture thereof to enhance its durability. Thereby, their potential impact on the environment was intended to be checked by allowing for carbon storage in treated wood for a longer period of time. Pine wood samples were vacuum-treated with three formulations: aminosilane, alkaloid and the mixture thereof. Resistance of wood against brown-rot fungus was assessed. Carbon content and carbon emission from wood samples were determined. The best results in wood protection against biodegradation and the highest carbon sequestration effectiveness were achieved for the two-component mixture. Interactions between these chemicals and wood prevented their leachability. This resulted in increased durability of the treated wood samples, sequestering carbon for a longer period of time and limiting its emission from wood to the atmosphere while exposed outside.