Based on field studies of mounds of Australian termites we estimate that on a global scale termites emit about 12¿1012 g/yr of methane (>20 tg/yr) and about 4¿1015 g CO2/yr (>8 pg/yr). Most of the detailed results are based on studies of the species Coptotermes lacteus. We found that in mid-latitudes the emissions vary seasonally. As much methane is emitted in the summers as in all other seasons combined. The soils a few meters from the mounds consumed methane at an average rate of 40 μg/m2/h. We found no evidence of net emissions of CO and found that H2 is consistently consumed by the mounds and the soils near the mounds. All six species studied produced chloroform. The concentrations of chloroform inside the mounds of C. lacteus were a thousand times greater than ambient levels, but our calculations show that termites are not likely to be a significant global source of chloroform. Finally, we used the results of our study, and others before us, to construct a view of the role of termites in the global carbon cycle.