Fact 1: Gases released during the use of fossil fuels causes global warming. Fact 2: Global warming causes ice storms. Given the two facts above, what causes ice storms?

Available choices: (I) colder weather; (II) Fossil fuels; (III) heat energy; (IV) a hydraulic system; (V) Water expanding; (VI) salt and water.; (VII) erosion; (VIII) less water;
Answer:
(II)