The Colorado River, integral to the southwestern United States, finds itself at a very precarious juncture in light of mounting climate challenges. Some recent studies offer mixed forecasts for the future of the river that will likely have significant impacts on regional stability and resource management strategies.
One new, more optimistic study published in the Journal of Climate now estimates a 70% chance that the coming 25 years will be wetter than the past two decades. Based on data gathered from the United Nations’ Intergovernmental Panel on Climate Change, the forecast shows how higher rainfall might offset some of the drying factors exacerbated by higher temperatures. “We want to emphasize that it’s not like, ‘Oh, there’s going to be water around, so let’s go party – we don’t have to do the hard work that needs to be done in terms of conservation and thoughtful management,'” said Balaji Rajagopalan, a water engineering professor and co-author of the study.
This optimistic perspective, however, is tempered by the intrinsic variability of climate models. Indeed, the same study allows for a 4% possibility that river flows will drop 20% over the next quarter-century. “All of our thinking, our acting, our management should be humble and recognize the nature in which we live,” Rajagopalan said.
Contrary to this rosy view, a paper by Bradley Udall of Colorado State University and Jonathan Overpeck of the University of Arizona in Water Resources Research paints a more pessimistic view. Their findings indicate that increased temperatures have cut Colorado River flows significantly. Flows reduced to 81% of the 20th-century average from the period between 2000 and 2014, a reduction of nearly 2.9 million acre-feet of water per year. Based on their assessment, Udall and Overpeck believe that the flow of the river will continue to decline with increasing temperatures in the future—an event that will eventually pose a severe challenge to water managers.
“The future of Colorado River is far less rosy than other recent assessments have portrayed,” said Udall. While this situation calls for planning based on lower river flows by water managers, current climate models project continual warming but uncertain precipitation patterns. We’re the first to make the case that warming alone could cause Colorado River flow declines of 30 percent by midcentury and over 50 percent by the end of the century if greenhouse gas emissions continue unabated,” Overpeck added.
But that’s not all; the megadrought ongoing in Southwestern North America since 2000 is soaking up river flow. This man-made climate change has supercharged the drought, already straining water resources while revealing a region’s vulnerability to protracted dry periods. A 22- to 23-year period starting in 2000 is the driest in the past 1,200 years. This drought is magnified by about 40% due to climate change, according to a new study led by Benjamin Cook of NASA’s Goddard Institute for Space Studies.
These results have huge implications for military and strategic planners. Water scarcity most likely will increase regional tensions, eventually disrupting agricultural production and straining local economies. Effective management and adaptation strategies are critical in mitigating these potential risks to the stability of the region.
Though it is promised faintly that there will be an increase in precipitation in the Colorado River Basin, on top of this, casts a great challenge due to the rise in temperature and prolonged droughts. Strategic planning and an effective, flexible water management policy would be required in an uncertain future for this life-essential resource.