Will Hurricane Florence be worse than Hurricane Andrew?

It’s hard to tell ahead of time whether one storm will be worse than another, because how bad a storm is really depends on the human impacts. To that point, many experts avoid using the term “natural disaster.” They say that a disaster is what happens when a natural hazard — hurricane, tornado, blizzard — overlaps with a human population. Absent that, it’s just weather .

It also depends on what you mean by worse. Hurricane Andrew was a memorable storm and one of the most costly on record when it hit Florida in 1992. But according to data from the National Oceanic and Atmospheric Administration, in recent years it’s fallen to sixth place in the United States by that measure, as Hurricanes Katrina, Harvey, Maria, Sandy and Irma have supplanted it when adjusted for inflation. Part of that is because more Americans are now living in the path of storms, and part of that is because climate change has played a role in making the effects of storms more severe .

As for fatalities, the deadliest storm on record in the United States happened in 1900, when surging waters killed more than 6,000 people in Galveston, Tex. This was before modern weather forecasting, however, and many people failed to evacuate the area.

How is climate change influencing Hurricane Florence and hurricanes more generally ?

NOAA says to think of warm water as the engine that fuels hurricanes. They only form in ocean waters that are at least 80 degrees Fahrenheit (27 degrees Celsius) to a depth of at least 165 feet, which is why the most intense Atlantic hurricanes tend to happen in late summer and early fall after the ocean has had a summer to warm up.

Because of climate change, the world’s oceans are warmer. Though climate change did not necessarily create Hurricane Harvey last year or Hurricane Florence this month, both of them were fueled by warmer than average waters.

Climate change can also make hurricanes wetter. Air temperatures are warmer, and basic physics tells us that warmer air can hold more moisture, which can translate into more rainfall.

To further exacerbate things, our warming climate seems to be causing hurricanes to stall, or linger longer in place. That’s what happened with Hurricane Harvey, which meandered back out to the Gulf of Mexico after making its first landfall in Texas, and then back in. When a hurricane sticks around, even more rain can fall over a single area, leading to catastrophic flooding. Of the 50 inches of rain that fell over some parts of Houston because of Harvey, 38 percent, according to one study, was attributable to climate change.