By IAN AUSTEN
OTTAWA — Environmental concerns over Canada’s oil sands have driven a debate over the process that has lasted for years. Now, some in Canada are trying to change the conversation. Advocates of oil sand production are arguing that the human rights record of Saudi Arabia and other Middle Eastern oil exporters makes oil sands a more ethical energy source, particularly for the United States. How successful they will be with Americans remains to be seen. But their argument has clearly caught the attention of the government of Saudi Arabia. Canada’s largest private broadcaster, CTV, has refused to show a