Traditionally, methane (CH 4 ) is anaerobically formed by methanogenic archaea. However, non-microbial CH 4 can also be produced from geologic processes, biomass burning, animals, plants, and recently identified soils. Recognition of non-microbial CH 4 emissions from soils remains inadequate. To better understand this phenomenon, a series of laboratory incubations were conducted to examine effects of temperature, water, and hydrogen peroxide (H 2 O 2 ) on CH 4 emissions under both aerobic and anaerobic conditions using autoclaved (30 min, 121 °C) soils and aggregates (>2000 μm, A1; 2000–250 μm, A2; 250–53 μm, M1; and <53 μm, M2). Results show that applying autoclaving to pre-treat soils is effective to inhibit methanogenic activity, ensuring the CH 4 emitted being non-microbial. Responses of non-microbial CH 4 emissions to temperature, water, and H 2 O 2 were almost identical between aerobic and anaerobic conditions. Increasing temperature, water of proper amount, and H 2 O 2 could significantly enhance CH 4 emissions. However, the emission rates were inhibited and enhanced by anaerobic conditions without and with the existence of H 2 O 2 , respectively. As regards the aggregates, aggregate-based emission presented an order of M1 > A2 > A1 > M2 and C-based emission an order of M2 > M1 > A1 > A2, demonstrating that both organic carbon quantity and property are responsible for CH 4 emissions from soils at the scale of aggregate. Whole soil-based order of A2 > A1 > M1 > M2 suggests that non-microbial CH 4 release from forest soils is majorly contributed by macro-aggregates (i.e., >250 μm). The underlying mechanism is that organic matter through thermal treatment, photolysis, or reactions with free radicals produce CH 4 , which, in essence, is identical with mechanisms of other non-microbial sources, indicating that non-microbial CH 4 production may be a widespread phenomenon in nature. This work further elucidates the importance of non-microbial CH 4 formation which should be distinguished from the well-known microbial CH 4 formation in order to define both roles in the atmospheric CH 4 global budget.