A group of scientists is calling for a moratorium on the development of tar sands and oil shale in North America. The Colorado River Basin contains the largest untapped deposits of oil shale in the world.
More than 100 scientists have asked policy leaders to consider the potential global impacts of developing tar sands and oil shale. They say the carbon-intensive extraction process is incompatible with limiting climate change.
Thomas Sisk, an ecology professor at Northern Arizona University, is one of the lead authors.