Climate change has emerged as one of the foremost threatening facts for life on earth. Construction of buildings and roads consumes nearly half of the raw material and energy across the world. Inside utility services like lighting, heating and air conditioning emit almost 47% of CO2 in the United Kingdom (UK), for example. Thus it can be concluded this sector is a major contributor to world climate change and requires intensive focus for review of materials, sourcing and building design as green building for reducing greenhouse gas emissions. Cannabis sativa L. (hemp) has received a lot of attention because of its multipurpose useability, short production cycle, low capital demand in cultivation, possibility of carbon-negative transformation and easy carbon sequestering.
Hemp can capture atmospheric carbon twice as effectively as forests while providing carbon-negative biomaterials. “Numerous studies estimate that hemp is one of the best CO2-to-biomass converters” said a senior researcher at the Centre for Natural Material Innovation, University of Cambridge, UK. “It’s even more effective than trees. Industrial hemp absorbs between 8 to 15 tonnes of CO2 per hectare of cultivation. In comparison, forests typically capture 2 to 6 tonnes of CO2 per hectare per year depending on the number of years growth, climatic region, type of trees etc”. Carbon-negative bioplastics and construction materials made from the plant can be used to “replace fibreglass composites, aluminium and other materials in a range of applications”.
The strong, stiff fibres that form the outside of the stem can be used to produce bioplastic products including automotive parts, wind-turbine blades and cladding panels. “With the hemp bioplastic cladding panels, we find that they are a suitable alternative to aluminium, bitumen-plastic and galvanised steel panels, requiring only 15 to 60% of the energy in its production”. In contrast to conventional agriculture, which emits large amounts of carbon, hemp farms do the opposite. “Agricultural land in the UK, on average, emits around 3 tonnes of CO2 per hectare per year. Hemp offers an incredible scope to grow a better future”. In addition, hemp produces more useable fibres per hectare than forestry.