This is not true, Brett. It's not even lower than two comparable mines (Kearl and Fort Hills). Teck claimed 40.4 kg CO2e/bbl in their environmental assessment. Kearl is lower (38.1kg/bbl in the EA), and FH was 9% below Kearl last year. EA has Muskeg River at 32.1 kg/bbl.
Would it be lower that imported crude? Likely lower than some imported barrels. Likely higher than others. Here's global crude by emissions intensity. Frontier would likely be +/- Kearl, so in about the top 20% of global barrels by GHG/bbl. 
Why is the @CDNEnergyCentre retweeting claims it knows (or should know) to be false? Teck's own documents say it will be 50th percentile or so of crudes refined in North America. Don't lie.
@CDNEnergyCentre Here's what @TeckResources says about Frontier: about half of the barrels refined in the US will be lower emissions intensity than the barrels it would (hypothetically) produce.
