By Valerie Cleland and Ian Hanna, graduate students at the University of Washington School of Marine and Environmental Affairs
You could call it a black gold rush. Technological advances like hydraulic fracking have made harvesting oil profitable in the U.S. again and changed the global petroleum market. For decades, the U.S. was dependent on oil imports and banned crude oil exports to protect domestic reserves. This changed in 2015, when the U.S. lifted the 40-year export embargo on crude oil and gave the oil industry access to the global crude oil market.