Tropical cyclones, the more general term for hurricanes and tropical storms, get their energy from the warm ocean water. 90 percent of the additional heat entering the Earth is going into the oceans, and some regions of the ocean are now 3-4°F warmer compared to the start of the 20th century. While the number of tropical storms and hurricanes (also known as typhoons or cyclones in other ocean basins around the world) is not necessarily increasing, the ones that do form can become more destructive due to the higher water temperature. Early research also suggests that warming water may lead to more rapid intensification of hurricanes.
Heavier rain from landfalling hurricanes produces more flooding of streams and rivers away from the coastline. Also, storm surge is more damaging as rising sea levels push water higher and farther inland.
Resources for covering tropical weather:
Click on the graphic for the full release