Two Great Lakes hit record low levels: Climate crisis or natural cycle?
Lake Huron and Lake Michigan are at their lowest levels since record keeping began a century ago, but experts say it's too soon to tell exactly what combination of issues is causing the drop.
(Page 2 of 2)
Researchers blame excessive dredging, both by the Chicago River system, which diverts water to the South, and the St. Clair River, which diverts water to deepen navigational channels to Lake Erie, Lake Ontario, and eventually the Atlantic Ocean. The International Joint Commission, a Canadian-US organization that looks for solutions to waterway issues, said it will release a report next month that examines the effect of dredging, among other factors, on water levels in the Great Lakes.Skip to next paragraph
Subscribe Today to the Monitor
David Allan, a professor in the School of Natural Resources and the Environment at the University of Michigan in Ann Arbor, says that, while the water drop is indeed historic, data shows that it follows a somewhat cyclical pattern. The current level, for instance, is just short of previous low points in the 1930s and '60s.
Whether or not water levels will continue to drop is uncertain, he says, as is whether or not climate change is entirely responsible. He says that factors such as warming temperatures and decreased precipitation are present, but suggests that others could be at play as well, such as dredging and natural fluctuations in water levels.
“The science is maybe a little early to fully understand fluctuations in order to fully identify climate change as a driver of this drop, but there is evidence of climate change over the last 30 or 40 years that would lead you to expect these water level drops to occur,” Dr. Allan says.
Because not enough is known to predict where water levels will go from here, the Corps has not yet taken action to stop them from dropping. Mr. Kompoltowicz of the Corps told AP that funding was limited and that nothing would be considered until 2015. Allan says it is unlikely the Corps will launch an expensive and long-term project without the certainty of a forecast.
“You could put in water-control structures at the St. Clair and hold back more water for Michigan and Huron, but there are downstream consequences if the water level drop is a natural one and water gets back up four or five feet higher than it is now,” Allan said. “So if you can’t conclude water levels are going to be low forever, you’re not going to put in an expensive engineering project that would take a very long time.”
RECOMMENDED: Are you scientifically literate? Take our quiz