Figure 5.7 The sulfur cycleWATER CYCLE
The water cycle is powered by energy from the sun. Solar energy evaporates
water from oceans, lakes, rivers, streams, soil, and vegetation. The oceans hold
97% of all water on the planet and are the source of 78% of all global
precipitation. Oceans are also the source of 86% of all global evaporation, with
evaporation from the sea surface keeping Earth from overheating. If there were
no oceans, surface temperatures on land would rise to an average of 153°F
(67°C).