<p>Trade in services is an effective booster for realizing green trade among economies. We collect panel data of 178 economies around the world from 2005 to 2020, and analyze the effect of service trade openness on CO2 emissions of export and its channels. The empirical results show that services trade openness and CO2 emissions of export have an inverted U-shaped relationship. The moderating effects analysis verifies that spillover effect of technological progress enhances the green effect of service trade openness and paves the way for CO2 emissions reduction while the scale effect of manufacturing development weakens the green effect and hinders the way for CO2 emissions reduction. The green effect of service trade varies by economic development level and geographical location. It is more obvious in economies with high economic development levels and better played in Europe and the U.S. In addition, membership in the OECD may reinforce the green effects of trade in services due to the strict environmental requirements at the entrance. Quantile analyses find that the higher the degree of service trade openness, the more obvious the green effect of service trade, encouraging economies to open up trade in services. Our study unveils that proper participation in world economic organizations and greater openness in service trade are beneficial to green development of the economy.</p>