Control of habitat's carbon dioxide level by biomass burning

Abstract: Consider a free-space settlement with a closed ecosystem. Controlling the habitat's carbon dioxide level is a nontrivial problem because the atmospheric carbon buffer per biosphere area is smaller than on Earth. Here we show that the problem can be solved by burning agricultural waste. Waste biomass is stored and dried, and burned whenever plant growth has lowered the atmospheric carbon dioxide level so that replenishment is needed. The method is robust, low-tech and scalable. The method also leaves the partial pressure of oxygen unchanged. In the initial growth phase of the biosphere, one can obtain the carbon dioxide by burning sugar or carbon, which can be sourced from carbonaceous asteroid materials. This makes it possible to bootstrap the biosphere without massive biomass imports from Earth.