Politics and Money

[lesgetrich]

Climate models currently predict that hurricanes will likely increase in intensity and the amount of flooding they cause. They do not predict an increase in frequency. Note that the following article was published before Hurricane Ian hit Florida...

A Force of Nature: Hurricanes in a Changing Climate - June 1, 2022 - By Angela Colbert, Ph.D., NASA’s Jet Propulsion Laboratory

In Brief:
Due to global warming, global climate models predict hurricanes will likely cause more intense rainfall and have an increased coastal flood risk due to higher storm surge caused by rising seas. Additionally, the global frequency of storms may decrease or remain unchanged, but hurricanes that form are more likely to become intense...

...In a hurricane, spiraling winds draw moist air toward the center, fueling the towering thunderstorms that surround it. As the air continues to warm due to climate change, hurricanes can hold more water vapor, producing more intense rainfall rates in a storm.

Moreover, according to Knutson, most models show that climate change brings a slight increase in hurricane wind intensity. This change is likely related to warming ocean temperatures and more moisture in the air, both of which fuel hurricanes. While most models show either no change or a decrease in hurricane frequency in a warmer climate, a greater proportion of the storms that form will reach very intense (Category 4 or 5) levels. In other words, while there may be fewer storms, the ones that form have a greater chance of becoming stronger.

Scientists continue to research these topics along with other important hurricane metrics, including any potential changes in the speed at which hurricanes move across the ocean, how large storms will get, and where hurricanes will go.

What Do Observations Show?

Climate models that help us understand future changes are a key part to the story, but have any changes in hurricane activity already been observed in recent years?

Since the 1980s, the hurricane record has shown a more active period in the North Atlantic Ocean. On average, there have been more storms, stronger hurricanes, and an increase in hurricanes that rapidly intensify. Thus far, most of these increases are from natural climate variations. However, one recent study suggests that the latest increase in the proportion of North Atlantic hurricanes undergoing rapid intensification is a bit too large to be explained by natural variability alone. This could be the beginning of detecting the impact of climate change on hurricanes, the paper states. In contrast, the frequency of hurricanes making U.S. landfall (a subset of North Atlantic hurricanes) has not increased since 1900, despite significant global warming and the heating of the tropical Atlantic Ocean.

One current focus of hurricane research is “sampling hurricanes by flying into them for more accurate data,” says Shirley Murillo, deputy director of NOAA’s Hurricane Research Division. These higher-quality data are important for improving hurricane model forecasts now and in the future. NOAA partners with NASA to collect measurements of various aspects of hurricanes over time. “NASA weather satellites are a powerful tool for observations, as people cannot fly into every storm to gather data,” Murillo says. Satellites help expand the observational record. With a longer, more detailed record, scientists can detect changes in long-term data trends over time.

This partnership is also developing the next generation of satellites to further improve hurricane observations for models. Dr. Marangelly Fuentes, meteorologist and program manager for one of NASA’s Earth research contracts, says researchers “run tests with potential new data to see how they would impact the model’s ability to correctly forecast a hurricane.”

For example, researchers may test to see if more detailed data about the ocean’s surface temperature in front of a storm help to accurately predict its intensity. If they find something useful, they can use this information to inform the design of instruments on future satellites. Then as more data are collected, this will lead to a better understanding of forecasting hurricanes and how they may be impacted by climate change.

What Does That Mean for Me?

Anyone who has experienced a hurricane knows how much damage it can cause to life and property. Flooding remains one of the biggest concerns when a hurricane comes ashore, and climate change will likely make that worse. With impacts from climate change (like sea level rise) already happening, the likelihood of a billion-dollar disaster from a hurricane remains very high.

If you live in hurricane-threatened areas, the best thing you can do is to be prepared. As we collect more data about hurricanes, we’ll better understand whether models correctly predicted hurricane changes from human-caused global warming. Fuentes says, “All of us have to do our part when seeing changes on the Earth, like the recent pattern of stronger hurricanes, to avoid it becoming something permanent.”