Ice is very reflective, therefore it reflects far more solar energy back to space than the other types of land area or open water.
ˈaɪs ɪz vˈɛɹi ɹᵻflˈɛktɪv, ðˈɛɹfoːɹ ɪt ɹᵻflˈɛkts fˈɑːɹmˌoːɹ sˈoʊlɚɹ ˈɛnɚdʒi bˈæk tə spˈeɪs ðɐn ðɪ ˈʌðɚ tˈaɪps ʌv lˈænd ˈɛɹiə ɔːɹ ˈoʊpən wˈɔːɾɚ.