It is well known that the Earth is a self heating planet by its physical and chemical processes inside. From physics, it is a geodynamo, and the electric current exists in it. By Joule rule, this current can produce Joule heat for the resistance of the material in it. The Joule heat distribution field on Asthenosphere-Lithosphere Boundary(ALB) has been obtained by using MAGSAT model. The distribution pattern was analyzed, and its environmental significance was discussed. It is found that the distribution of high value centers of Joule heat on ALB have good corresponding to the distributions of global geothermal zones and volcanoes, and the horizontal scale of Joule heat is very comparative to the horizontal scale of geothermal vortex, to the space distance between rainy belts in China, and to the space distance between the high correlation coefficient belts of precipitation and temperature The centers of Joule heat match the maximum annual precipitation centers in globe very well. And it is also found that the highest center of Joule heat in globe locates under Tibetan Plateau. These phenomena are of very important to understand the Earth as a whole, and the interactions between spheres. Finally, the possible relation between geomagnetic field and climate change was discussed.