By Maha El Dahan, David Stanway and Valerie Volcovici DUBAI (Reuters) – The COP28 climate summit in Dubai started with all the ingredients for spectacular failure: It proposed an end to the fossil-fuel era at a conference situated in Arab oil country amid overt opposition from the powerful oil-producer group OPEC. Landing a pact that all 196 countries could live with took deft maneuvering by the conference host, the United Arab Emirates, along with back-channel diplomacy from the United States’ and China’s top climate envoys, sources told Reuters. The COP28’s UAE presidency employed a strategy…