By 2050, some 50% of the world’s population will live in the tropics (State of the Tropics, 2020). Tropical Low-to Middle-Income Countries (LMIC’s) have a shortage of housing which lacks structural quality and durability (UN-Habitat, 2016) yet have a latent opportunity to utilise locally sourced bamboo (Lobovikov, Paudel, Piazza, Ren, & Wu, 2007).
Right now, our global construction industry has a decisive role to play in climate-change mitigation. Each year, more than 4 billion tonnes of cement are produced (Lehne & Preston, 2018), and cement alone accounts for 7-8% of all human (anthropogenic) CO2 emissions (Andrew, 2018). In order to meet our Paris Agreement climate targets, we will need to reduce current production, however, the increasing levels of urbanisation in tropical developing economies (Nations, 2018), paired with the levels of construction required to meet Sustainable Development Goal 11 suggest cement production could increase by as much as 23% by 2050 (Harvey, 2018).
Alternative building materials are clearly needed if the Paris Agreement climate targets are to be met. By increasing the use of bamboo, a lightweight, sustainable natural material that absorbs CO2 during its growth, we will potentially be able to lower our current dependence on steel and concrete, which produce CO2 during their manufacture.
Replacing conventional materials with bio-based materials that store carbon can be one solution to help us reduce our overconsumption of materials like concrete and sand (Pomponi, Hart, Arehart, & D’Amico, 2020; UNEP, 2019; van der Lugt, 2017). But what are the issues with sand and gravel?
Sand and gravel are a challenge to trace to their source and monitoring of global sand resources is lacking (UNEP, 2019). Extraction rates are exceeding natural sand replenishment rates, and sand and gravel resources are the second largest resource extracted and traded by volume after water (UNEP, 2019).
The scale of the challenge inherent in sand and gravels extraction makes it one of the major sustainability challenges of the 21st century (UNEP, 2019). Are use of concrete has meant that it has become the most widely used building material on Earth; we use twice as much concrete every year as steel, aluminium, plastic, and wood combined (Beiser, 2018, p. 219).
Physical impacts of sand mining include reduction of water quality and destabilization of the stream bed and banks. Mining can also disrupts sediment supply of habitats downstream (Ashraf, Maah, Yusoff, Wajid, & Mahmood, 2011).
In many regions of the world, timber will most likely never be able to provide the sustainable alternative we need. Given the speed of growth and quantity required, extraction could have a deleterious effect on ecosystems (Pomponi et al., 2020).
Sustainable development is the idea that the future should be a better, heathier place than the present and the past (Blewitt, 2017). Therefore we need to develop the use of high yield cultivated construction materials such as bamboo (van der Lugt, 2017). Bamboo can absorb carbon dioxide and stabilise slopes to tackle the effects of deforestation (Tardio, Mickovski, Stokes, & Devkota, 2017).
In tropical developing economies, it is a reality that the architect will not design the majority of housing (Hardoy, 1989). The minimum construction materials are purchased, and design and engineering input is often unaffordable.
Architects can however be active in reducing the cost of design and raise awareness of good practices promoting open source designs of adequate housing which ensure structural and aesthetic integrity (Seksan, 2019).
At the AA-ITB BambooLab programme, we want to look at the role of bamboo as a practical solution to our over consumption of concrete and manmade materials and through our design work produce an activist portfolio using pioneering design methods and tools, to provide a glimpse for how a global, sustainable construction industry could look. From one based on extraction, to one based on restoring ecologies, reducing CO2 emissions, and providing new skills, economies and resilient buildings.