Producing a barrel of oil from the oil sands produces 3.2 to 4.5 times more greenhouse gases than conventional oil produced in Canada or the United States .
Extracting crude from the oil sands is incredibly energy intensive and consumes significant quantities of natural gas, electricity and diesel. This means that producing crude from the oil sands releases much more greenhouse gas emissions than crude from conventional sources.
Because of this, a Honda Accord burning tar sands gas has the same climate impact as driving a Chevy Suburban using conventional gas.
Or to put it another way, fuelling ten percent of USA transportation with oil sands oil increases the climate impact by nearly 40 megatonne equivalent of Carbon dioxide (MtCO2) - That’s equal to adding 8 million cars to US roads!
Defining “conventional” – There are many variances between different types of crude and different methods of oil sands extraction. Naturally, if one were to cherry-pick the highest greenhouse gas emitting conventional crude project and compare it to the lowest greenhouse gas emitting oil sands project (or vise versa), you would get very different numbers. To be consistent, many studies refer to the 2005 U.S. baseline (the average of all fuels consumed in the U.S. that year, calculated by the Environmental Protection Agency).
Production versus “wells-to-wheels” lifecycle
“Production” refers to the extraction of the oil through either in situ or mining methods and the upgrading process. The major difference between oil sands crude and conventional oil greenhouse gas emissions can be seen in this stage.
This looks at the entire lifecycle of the product, from it being extracted, upgraded, refined, transported (pipeline, tanker) to combustion (in your gas tank). The biggest difference in emissions between conventional crude and oil sands crude occur at the extraction/upgrading stage, but even then, the full “wells-to-wheels” lifecycle of oil sands crude is still 22% more climate damaging than conventional oils .
Ten Percent of USA transportations emissions calculations:
Ten percent of USA transportation emissions in 2010 equalled 175 million tonnes of CO2 (MtCO2) . Adding 22% to that adds 39 MtCO2. The average car in USA emits 4.8 tCO2 per year . Eight million cars at 4.8 tCO2 each yields 38.4 MtCO2.
Honda Accord/Chevy Suburban Calculations:
The average passenger vehicle in the USA got 21.6 miles per US Gallon in 2010  and lasted for 212,000 miles . This requires burning 9,722 gallons of gasoline per vehicle, which will produce 87 tonnes of CO2 (tCO2). Gasoline produces 8.92 kgCO2/USGallon . Using oil sands gasoline increases wells-to-wheels emissions by 22% leading to an extra 19 tCO2 for an average vehicle.
The US EPA lists 2012 Honda Accord Coupe at 21 mpg and 2012 Chevrolet Suburban 1500 2WD at 17 mpg . The Accord will drive 2,100 miles on 100 gallons of gas. With oil sands gasoline the “wells-to-wheels” climate impact will be 22% more — equal to burning 122 gallons. The Suburban needs 123 gallons to go the same distance.
National Energy Technology Laboratory, Development of Baseline Data and Analysis of Life Cycle Greenhouse Gas Emissions of Petroleum-Based Fuels, DOE/NETL-2009/1346 (2008), 12.