Fired Bricks: CO₂ Emission and Food Insecurity

Fired bricks are used for construction purposes over the millennia, going back to the Indus Valley Civilization. The traditional brick-making process involves removal of agriculturally productive topsoil rich in clay and soil organic matter contents. In addition to the removal of the fertile topsoil and accelerated degradation by other processes, the traditional clay brick making process also emits CO₂ and other gases into the atmosphere. Therefore, the present study aims to assess the impact of brick making in India on: (i) the magnitude of annual CO₂ emission and (ii) the loss of agricultural production. Currently, 0.7 Mha (million hectare) of agricultural land is under brick kilns that produce ≈250 billion bricks annually. It is estimated that soil organic carbon lost through the firing process of 250 billion bricks is 5.58-6.12 Tg (teragram) (20.48-22.46 Tg CO₂), and in conjunction with clay burning and coal combustion the process releases 40.65-42.64 Tg CO₂ into the atmosphere per annum. Brick kiln also impacts quality of the exposed subsoil, and may also reduce 60-90% agronomic yield. Therefore, brick making from topsoil exacerbates food and nutritional insecurity by degrading soil quality, and increases risks of climate change through increase in gaseous emissions.