I think you should look at line 109:
uniforms['texture'].value = THREE.ImageUtils.loadTexture(imgDir+'world3.png');
This is where the background image for the globe is loaded in. You’ll notice in your browser debugging console that world3.png is not loading correctly, because you haven’t included it in the project. You can upload a file make it appear as your base texture.
The globe is a SphereGeometry built with a ShaderMaterial. The earth shader is defined on line 29 and you can edit the fragment shader to change the way the texture appears.