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.
Global warming is already having significant and harmful effects on our communities, our health, and our climate. Sea level rise is accelerating. The number of large wildfires is growing. Dangerous heat waves are becoming more common. Extreme storm events are increasing in many areas.