Read here. AGW promoters predict that the unrelenting human CO2-induced global warming will cause ecosystems to change. In the case of the North American Great Lakes ecosystem, this would mean that winter temperatures would continually rise and winter ice coverage would no longer exist. As the the below graph of the scientists' research shows, both temperatures and ice coverage have been highly variable across the Great Lakes for several decades, which is consistent with natural climate variability, and not at all consistent with global warming alarmist predictions. (click on image to enlarge)
"Wang et al. conclude that "natural variability dominates Great Lakes ice cover," and that any trend in the data -- of which there are some of a few years and one that is more lengthy -- "is only useful for the period studied." Hence, there is no reason to attribute any change in the annual average ice area of the North American Great Lakes to anthropogenic global warming, especially when one considers the fact that there was no net warming over the period of time Wang et al. investigated. If anything, there was a slight cooling."