Hemp: twice as effective at capturing carbon as trees!

What if hemp could help us in the fight against global warming? Known to mankind for thousands of years and cultivated for everyday use, reintroducing hemp among our favourite crops could have benefits that have not previously been considered: it captures twice as much carbon as trees!

What are the benefits of hemp?

Let’s review the multiple uses of hemp! You probably know that hemp belongs to the same species as cannabis. The variety Cannabis sativa L is specifically referred to as "hemp", which is characterised by a lower THC (tetrahydrocannabinol) content, less than 0.2% per dry extract. It is characterised by fibres that have various purposes. 

• In textiles: it produces soft fabrics, very popular among our ancestors! Other examples include ropes, bags, ship sails, etc. 

• In food: its seeds are edible and have nutritional value. 

• In fuel: the oil produced can be used as fuel for cars.

And the benefits of hemp don’t stop there! Dr Darshil Shah, a researcher at Cambridge University who studies biomaterials and natural fibres with a view to providing alternatives to conventional materials, is particularly interested in hemp. He suggests using it to replace fibreglass composites, aluminium and other materials, particularly those used in building and car construction. We think that the production of materials such as concrete or plastic has a negative impact on the environment, whether due to the exploitation of oil, destruction of coastlines for sand, or limited recycling capacity. Hemp is biodegradable and is, therefore, an interesting alternative.

Hemp: a natural CO2 collector

Let’s get back to carbon capturing! As a reminder, photosynthesis involves leaves absorbing carbon dioxide (CO2) from the air, which is then transformed into oxygen (O2) and released as a waste product. Any plant containing chlorophyll (which gives the leaves their green colour) carries out this process. Dr Shah claims that hemp is twice as effective as trees! He states that 8 to 15 tonnes of CO2 per hectare is captured by hemp, while forests only capture 2 to 6 tonnes. Of course, this rate depends on criteria such as the species of trees in the forest and their size. 

This can be explained by a rather simple phenomenon: plants reach their maximum carbon capture efficiency in the middle of their development and, once at their maximum growth, they release the captured carbon into the air. A forest has plants at various stages of development, but some grow more slowly than others. 

Hemp is a very fast-growing plant and therefore quickly reaches a stage where it captures CO2 at its maximum capacity. Then, as it will be harvested for other uses, it will have hardly any time to release it.

Another factor to consider: organic farming. In fact, in typical cultivation techniques, 30 to 40% of pollution comes from pesticides and fertilisers. Hemp is a hardy plant that grows well in different types of soil. By adding a more environmentally responsible culture, the benefits would easily and naturally add up.

Hemp is therefore:

• a plant with multiple uses that could help to replace some of our consumption of plastic, building materials, wood pulp paper, or other more pollutant textile fibres. 

• a plant which can be used to make supplements that are good for health, 

• a plant used to produce an oil which can be used as a fuel 

• a plant that is even more effective at capturing carbon from the atmosphere than the trees in forests

 We should reassess the uses of hemp plants!