Canada won’t impose new carbon-emission rules on its oil and gas sector given the current turbulence in the industry, Prime Minister Stephen Harper said Tuesday.  “Frankly, under the current circumstances in the oil and gas sector, it would be crazy economic policy to do unilateral penalties on that sector. We are clearly not going to do that,” Mr. Harper said Tuesday in Canada’s legislature, in response to a lawmaker’s query about the lack of environmental rules for the energy sector.  “We are not going to kill jobs,” Mr. Harper said.  Canada’s important energy sector has been hard hit by the recent collapse of world oil prices, and a number of Canadian producers have announced plans to scale back spending and cut dividends as crude oil nears a five-year low.