"Most of the time, computer models predict that lake levels will drop by a foot or more during the next century because warmer weather will cause more water to evaporate off the Lakes...But a few newer models suggest lake levels could actually increase a little because the climate is likely to get wetter, too...And, it could dim [or brighten] the amount of electricity produced by the region's hydroelectric plants".
Your head is exploding, right? Take a deep breath, look away from the computer, and turn off the news. What things are common to the conflicted outcomes?
Two high level examples: 1.) water resource managment counts in every outcome. Whether its flooding, and the commensurate property and crop damage, versus the opposites of drought, potable water, and agricultural losses, the need for better water resource planning, conservation, control projects, and emergency response is common to all modeled outcomes. 2.) Corollary: extended drought outside the Great Lakes basin will surely bring waves of new migrants to the Great Lakes area: when a crisis comes...we're making an analogy to the mass migrations caused by the Dust Bowl in the early 1930's.. it's going to be faster, easier, and more logical for people to move toward the water, as opposed to trying, in crisis mode, to move Great Lakes water to widely dispersed populations suffering economic decline.
If long term climate shifts continue and expand the already extensive drought problems, 'leading the horse to water' becomes the PE, whether the Great Lakes are "up or down". What's left hanging is who moves to the Lakes first, the wealthy and middle classes, or the poor and alien immigrants.
What's a TreeHugger to do?
Think about the prospects for: locally produced foods; changing uses of parks and recreational lands (hint: tented refugee camps); housing with resource efficient appliances; solar powered wells; biodiesel supply and demand volatility; water saving technologies to invest in, or design; your education or career plans; electoral platforms; States rights v.s. Federalism; and, International water treaties. All flow from the predermined element.
Beat the Pundits at their own game. They cite fantastic or contradictory sounding hypothetical outcomes: you focus on the pre-determined element. A similar process ought to work for whichever region you live in. Look for the climate modeling scenarios.