Emissions from Midwest oil refineries are expected to jump by up to 40 percent in the next 10 years, thanks in large part to an industry-wide trend of sourcing crude oil from Canada’s tar sands. The sands produce petroleum of such poor quality that it requires more energy — and thus more pollution — to process it into usable fuel. The trend flies in the face of national and regional efforts to curb greenhouse gases, not to mention oil companies’ lip service to renewable energy and climate-change mitigation. “We take climate change very, very seriously,” says Bill Gerwing of oil giant BP, which is proposing to expand a Chicago-area refinery to process more Canadian crude. How seriously? “We are willing to pay for our emissions with offsets.” Ah. That seriously.