Reuters: Germany's clean energy drive earned it a reputation as a green leader but a domestic row over coal has highlighted the challenge of balancing economic and environmental demands and threatens its ability to lead by example. Angela Merkel, once dubbed the "climate chancellor", hopes to encourage the Group of Seven industrial nations to commit to tough goals to cut greenhouse gases at a June 7-8 summit in Bavaria before a larger year-end United Nations climate meeting in Paris. In charge of Europe's...