Usually a word or concept can be defined in just one sentence. A definition essay, however, needs to be several paragraphs. Therefore, the definition must be extended to include examples, details, personal experience, description, causes, effects, analysis, etc.
Global Warming Causes More Hurricanes. It could be that the tropical oceans will become warmer with a simultaneous decrease in upper atmosphere temperature, which will cause stronger convection, which will help tropical storms to become more organized and stronger so there will be stronger hurricanes.
Hurricanes do an important job for the Earth. They help move heat from warm tropical places to the cooler temperate zone. They form in the tropics just north and south of the equator where winds to turn as they blow because Earth rotates and where the ocean water is warm.