In Alberta, Canada, amongst its mixture of sand, clay, water and other minerals, the tar sand’s heavy and viscous component bitumen, a thick, sticky form of crude oil is extracted through two methods; open-pit mining for shallower deposits (<75 m), and in situ for deeper deposits (>75 m). This degree project consists of a comparison between these two extraction methods impact on air, nature and water, which all have been evaluated by reviewing and analyzing literature. Studies showed that in situ methods cause a higher impact on air than open-pit mining, through higher emissions of greenhouse gases and sulfur dioxide (SO2), and will surpass the carbon dioxide (CO2) emissions caused by the open-pit mines when the shallower, more accessible tar sands dwindle. Open-pit mining causes a higher impact on water due to its large tailing ponds that causes leakage of processing water and fine tailings, polyaromatic hydrocarbons (PAH: s) and these 13 following elements considered priority pollutants (PPE) by the US Environmental Protection Agency (EPA); antimony (Sb), arsenic (As), beryllium (Be), lead (Pb), cadmium (Cd), copper (Cu), chromium (Cr), mercury (Hg), nickel (Ni), selenium (Se), silver (Ag), thallium (Tl) and zinc (Zn). However studies remain unclear whether or not in situ methods are worse due to underground tailing ponds. Finally, when it comes to nature, open-pit mining causes a more direct environmental impact through deforestation, drainage of peat and wetland, and blasting of rock. In situ methods however, seem to cause more of a long term environmental impact through fragmentation. Dividing the landscape into smaller units through roads, wells, pipelines and seismic lines, leads to domestic biodiversity and homogenization of flora and fauna as unfavorable conditions is created for the nature’s wildlife. In conclusion, in situ methods causes a bigger impact on air than open-pit mining, while open-pit mining causes a bigger impact on water. Due to lack of time and resources, more research about the direct impact on nature is needed to fully evaluate which of the two extraction methods causes the least environmental impact.