Carbon sink

Our Earth’s natural green house effect makes life as we know it possible and carbon dioxide plays an important role in providing the warm temperature that our planet enjoys. When plants grow they take up carbon dioxide from the atmosphere. Some lucky plants get to stay in place to grow and live a long happy life in the ground. When the plant dies and rots down at the end of its life CO² is released back into the atmosphere. This is nature’s way however human (anthropogenic) activity over the past few centuries has increased the amount of carbon dioxide being released into our atmosphere by burning fossil fuels like coal, oil or gas and through deforestation. This recent rise in anthropogenic emissions exceed the amount that can be taken up or balanced out by natural carbon sinks.

A carbon sink is a reservoir that absorbs more carbon than it releases and thereby lowers the concentration of CO² in the atmosphere. Examples include dense forests, soil, the ocean and a hempcrete home!

Hemp grows faster than timber and absorbs CO² quicker creating a hard woody stem of 2-4 meters in only 5 months. The CO² of hemp is ‘locked up’ in the building, acting as a carbon sink. So even accounting for the embodied energy in its production, transport and construction, a hempcrete wall represents negative carbon emissions. Thereby a net reduction rather than net increase in atmospheric CO² (carbon sequestration). Furthermore, the lime binder present in a hempcrete wall performs carbon sequestering by removing CO² from the atmosphere and storing it for the life of the building in a process known as carbonation. Hemp is renowned for being a sturdy and long lasting material, with evidence of hemp being used in buildings that are hundreds of years old.

By utilising hempcrete you are creating a huge positive environmental impact and it is nice to know that as humans we can have a strong contribution to reducing CO² naturally.