The chart shows what has happened to five lakes covered in ice in North America. If we take a look at Superior lake, we see that in the year of 1973 to 1992 the ice cover was at 26 percent but in the year of 1992 to 2012 the percentage of ice cover decreased by 10.
Michigan lake was 14 percent covered in ice in the year of 1973 to 1992 but went to 9 percent in the year of 1992 to 2012. Huron lake was 27 percent covered in ice in 1973 to 1992 and decreased to 21 percent in 1992 to 2012. Erie lake in 1973 to 1992 had the most ice covering at 30 percent but in 1992 to 2012 decreased to 28 percent. And lastly, Ontario lake had the least ice covering than others. It was 6 percent covered in ice in 1973 to 1992 and went down to 4 percent in 1992 to 2012.
Overall, we realise that due to global warming, all ice covers have decreased in the year of 1992 to 2012. The Earth’s heat is rising as time passes and causing the ice to melt and the weather to become warmer.