CO₂ May Curb North Atlantic Hurricanes, Study Reveals

A new study from researchers at Princeton University suggests that future warming patterns and rising carbon dioxide levels could lead to a decline in the number of hurricanes in the North Atlantic by the end of the century.

The findings challenge some previous assumptions about how average tropical temperatures affect storm frequency and highlight the importance of focusing on the warmest tropical waters when predicting hurricane activity.

The study, led by scientists from Princeton’s Department of Atmospheric and Oceanic Sciences, used thousands of years’ worth of high-resolution climate model simulations to investigate how changes in sea surface temperatures (SSTs) and CO₂ levels influence the number of hurricanes that form in the North Atlantic each year.

Traditionally, scientists have used tropical average SSTs as a key predictor of hurricane frequency. Warmer oceans generally provide more fuel for storm formation, and models have often linked increased storm activity with higher tropical SSTs. However, this new research shows that focusing on the warmest areas of the tropical ocean provides a more accurate picture.

According to the researchers, these warmest SSTs have a strong influence on atmospheric temperatures in the free troposphere—the layer of the atmosphere where hurricanes form and intensify. Through deep convection, which occurs only in the hottest tropical zones, these temperatures can shape the conditions that either support or suppress hurricane formation.

The team developed a new index based on these warmest SSTs and found that it consistently outperformed models that rely on tropical averages. Not only did it better explain hurricane activity in current and past climate simulations, but it also provided more reliable projections under future warming scenarios.

One of the key insights is that when warming is uneven—what scientists call “patterned warming”—the areas with the hottest SSTs are expected to warm more than the broader tropical region. This disproportionate warming leads to a more stable atmosphere, which can reduce hurricane frequency in the North Atlantic.

In addition, the study found that higher levels of atmospheric CO₂ appear to suppress hurricane formation, even when sea surface temperatures remain constant. This CO₂ effect adds another layer of complexity to how storm activity may change with climate.

Using sea surface temperature projections from the latest generation of climate models (CMIP6), the Princeton researchers applied their statistical model to forecast hurricane activity through the year 2100. The result is a consistent downward trend in the number of North Atlantic hurricanes, a finding that contrasts with some earlier studies that predicted increases or greater uncertainty.

The authors stress that the accuracy of these projections hinges on using the correct indicators. Models that rely on tropical average SSTs, they note, not only perform poorly under future warming scenarios but sometimes even predict the wrong direction of change in storm frequency.