After boiling and simmering water for 30 minutes on five different stoves, researchers measured total greenhouse-gas emissions (normalized here to grams CO2 equivalent).
Source: MacCarty, N. et al. 2008. A laboratory comparison of the global warming impact of five major types of biomass cooking stoves. Energy and Sustainable Development doi:10.1016/S0973-0826(08)60429-9.
Photos by Nordica MacCarty