The correct answer to this open question is the following.
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If you look at a graphical representation of at least a 50-year period between 1920 and 2014, you would see "increasing global temperatures, melting ice caps and glaciers, and rising sea levels."
Climate change or global warming is not new for planet earth. It is a phenomenon that has happened in the past according to scientists and national agencies. It is believed that global warming had caused natural disasters such as the melting of ice caps and the flooding of many lands on Earth, destroying life forms.
That is why right now, many agencies are closely researching climate change. Among those institutions are the US National Academy of Sciences, the Geological Society of America, the American Meteorological Society, and the National Aeronautics and Space Administration.