Agence France-Presse: The era of oil gushing from ground wells is over and can only be replaced by costly and complex refining of deposits such as Canada’s oil sands to satisfy rising global energy needs, said a senior oil executive. Pressed about the high cost of oil sands extraction and attacks by environmentalists worried about its contribution to global warming, Jean-Michel Gires, president of French-based Total’s Canadian subsidiary, told AFP he is optimistic specifically about the future of Canada’s …