Peter Yeung: … Though public awareness is low, some scientists believe “biochar” is quietly becoming the world’s first major carbon removal success story … A kind of black powder, it is made by heating up organic matter such as wood chips, manure, leaves, or indeed coffee husks, in the absence of oxygen (to prevent its combustion, which would emit CO2) in a process known as pyrolysis. The creation of biochar removes CO2 from the atmosphere, and in doing so, turns the natural decay of organic matter into a carbon-negative process  Read here …