[en] The use of biomass for energy accounts for 127 TWh (457 PJ) in the Nordic countries Denmark, Finland, Norway and Sweden which is 9% of the total energy consumption. Combustion of biomass is CO₂-neutral in the greenhouse effect balance. However, emissions of NO_x, N₂O, CO and CH₄ contribute either direct or indirect to the greenhouse effect. Experiments have been performed in three different wood stove units, a traditional stove and two new stoves. The two new stoves consist of a staged combustion unit and a catalytic stove. The emissions of NO_x, N₂, CO and unburnt hydrocarbons (UHC) in addition to O₂ and CO₂ are measured with continuous analyzers. The emissions of NO_x tend to decrease (in ppm) during the combustion cycle, while the emissions during the combustion cycle in g/kg wood increase in the charcoal phase compared to the pyrolysis phase. The average NO_x emissions are higher for the catalytic stove than for the staged stove, but the average CO and UHC emissions are lower. The emissions of N₂O are in general low, below 10 ppm. The total emissions of greenhouse gases for different wood stoves are calculated and compared to oil combustion. 9 refs., 12 figs., 1 tab