The anthropogenic emissions of greenhouse gases (GHG) are widely realized as the predominant drivers of global warming, but the huge and increasing anthropogenic direct heat emissions (AHE) has not gained enough attention in terms of its role in the warming of the climate system. Based on two reasonable assumptions of (1) AHE eventually transfers to the Earth energy system and (2) the net warming is only driven by the net radioactive forcing (RF) from either GHG or other causes, we analyzed the role of AHE in global warming. The mean annual total AHE of the four main sources including energy consumption, residual heat of electricity generation, biomass decomposition by land use and cover change (LUCC) and food consumption was estimated to be 4.41x10 20 J in 1970-2010, accounting for 6.23% of the net annual heat increase of the Earth reported by IPCC AR5 for the period. The mean annual radioactive forcing (RF) by AHE was up to 29.94 mW/m 2 globally in 1981-2010, less than the annual net increase of total GHG (34.80 mW/m 2 ) but more that of CO2 (24.43 mW/m 2 ). The results suggested that AHE played a great role in global warming, urging us to pay more attention to DHE for a better evaluation of RF and more reasonable energy policy including non-GHG energy in the future. Warming of the climate system is unequivocal and the anthropogenic emissions of greenhouse gases (GHG) are currently considered as the predominant drivers. 1 The role of the huge and increasing amount of anthropogenic heat emissions (AHE), different from the yearly-fluctuating solar-Earth-energy system in terms of energy source and/or timescale, 2, 3 plays in global warming was rarely evaluated by previous studies on climate system such as IPCC AR5. 1,2,3,4 However, AHE, along with processes of CO2 emission in most cases, can actually influence the heat balance of the Earth, possibly affecting the trajectory of global climate change significantly. There was therefore a need to explore the importance of AHE in the climate warming, especially compared to that of GHG. Energy consumption, residual heat of electricity generation, biomass decomposition and food consumption are the major sources of AHE. We thus estimated AHE induced by these four anthropogenic activities and discussed their contribution to climate warming in 1971-2010 at a global scale based on two reasonable assumptions of (1) AHE eventually transfers to the Earth energy system and (2) the net warming is only driven by the net radioactive forcing (RF) from either GHG or other sources. As shown in Table 1, (1) AHE caused by energy consumption was estimated with assuming 10.0% of world's primary energy consumption 5 was released in the forms of motion, light and sound etc. rather than AHE (A reported ratio of un-heating energy consumption was 6.7%) 2 . ( 2) Residual heat of electricity generation (nuclear, hydroelectricity and renewables), which was not included in energy consumption above was derived based on a thermal equivalence with assuming a 62% of heat lost in modern thermal power stations. 5 (3) AHE from biomass decomposition with land use and cover change (LUCC) was combined with biomass composition based on the CO2 released from LUCC. 6 c : The heat released from biomass decomposition assuming a rate of 37000 j/(g carbon), while the less solar energy fixed by plant and evapotranspiration induced by LUCC were excluded. d : The shares of animal and plant foodstuff and the heat for animal foodstuff production converted via feed conversion ratio were not considered. e : Like IPCC's relative to 1750, annual net increase of RF from total GHG and CO2 was abstracted as a year-by-year relative. 5 3 / 4 The mean annual total AHE was 4.41x10 20 J in 1970-2010, and it was mainly contributed by energy consumption . As reported by IPCC AR5, "more than 60% of the net energy increase in the climate system is stored in the upper ocean (0-700 m)" and "the increase in upper ocean heat content during this time period estimated from a linear trend is likely 17x10 22 J", 1 the whole net heat increase of the Earth was no more than 28.3x10 22 J (e.g. 26.1x10 22 J when 65% employed), equivalent to an average annual heat increase of 70.75x10 20 J, in 1971-2010. Thus, AHE accounted for 6.23% of the net annual heat increase of the Earth in 1971-2010. Because we did not consider the AHE from many other sources (see footnotes of Table 1) and a high value of the net heat increase in the Earth (28.3x10 22 J) was used in our calculation, the contribution of AHE estimated here was likely to be an underestimate. The work was partially 41171420), the Key Research Program of the Chinese Academy of Sciences ( KZZD-EW-04), the of China ( 2014FY210100) and the West Light Foundation of the Chinese Academy of Sciences. The work was partially 41171420), the Key Research Program of the Chinese Academy of Sciences ( KZZD-EW-04), the of China ( 2014FY210100) and the West Light Foundation of the Chinese Academy of Sciences.