Hurricanes. Tornadoes. Earthquakes. Floods. Avalanches. Wild fires. These events have been happening for millennia and have affected humans throughout every part of the globe. According to the International Journal of Disaster Risk and Reduction External, natural disasters are defined as "...catastrophic events with atmospheric, geological, and hydrological origins (e.g., droughts, earthquakes, floods, hurricanes, landslides) that can cause fatalities, property damage and social environmental disruption."

Arguably the most famous earthquake in U.S. history is that of San Francisco in 1906. It occurred on April 18 and had an estimated magnitude of 7.9 (estimated because the Richter Scale, which is used to measure the magnitude of earthquakes, was not invented until 1935 by Charles F. Richter). Though it lasted less than a minute, the damage was extensive and the death toll, though uncertain, was up to 3,000. The earthquake and subsequent fires caused by ruptured gas mains, which lasted for four days, destroyed about 80% of city. The earthquake, one of many for this region, occurred due to the tectonic activity along the San Andreas Fault, which forms the boundary between the Pacific and North American plates.

In 1900, a hurricane made landfall near Galveston, Texas. Not only was it the deadliest hurricane in U.S. history, but it was the deadliest natural disaster in U.S. history! This hurricane made landfall on the night of September 8 and was estimated as a category 4 with a storm surge of over 15 feet that devastated the city. There has been speculation on the total number of fatalities, but the most cited number is 8,000, which is a significant portion of the nearly 38,000 in total population at the time.

The 2019-2020 bushfire season in Australia was the worst on record; 46 million acres were burned by hundreds of fires which caused dozens of fatalities. The fires' effect on air quality was demonstrated by the Air Quality Index putting several parts of the country into the hazardous zone, including areas around Sydney. The toll of the fires could also be seen in the wildlife populations. It is estimated that over 1 billion animals died during the course of the fires, including many endangered species.

The resources in this guide provide information on how and why these events occur and what people can do to better prepare for the next occurrence.