2. Volcano

From Iceland to Italy, experts take an in-depth look at four imposing volcanoes, each bigger, deadlier and more explosive than the last.

3. Earthquake

Harrowing accounts of earthquakes and tsunamis in Los Angeles and Japan hone in on looming threats in the hotbeds of the earth's seismic activity.

4. Hurricane

A closer look at the ravaging effects of Hurricane Ida in 2021 reveals how rising global temperatures are pushing storms to grow more powerful than ever.