“For decades, the mathematics of waterborne transport here were simple. For every 10 to 11 metric tons of cargo that moved into and out of the Toledo port, about one metric ton of sediment left the channel. (Last year, 10.4 million metric tons of cargo were handled at the port.)

But with climate change, the equation is almost certain to get more complex and more expensive, say scientists and port managers. More mid-winter snow melts and rainstorms — and more frequent heavy rainfalls, especially in spring — may lead to higher soil-erosion rates, meaning that Great Lakes rivers are likely to carry more soil into harbors. Higher air temperatures already are warming the Great Lakes, blocking ice from forming, and increasing rates of evaporation that may lead to lower lake levels.”