Climate heating caused by fossil fuel pollution supercharged Hurricane Beryl during its unusually early July push from the heart of the tropical Atlantic Ocean to the coast of Texas, scientists said Friday.

Beryl maintained tropical storm force passing into the Gulf of Mexico and was strengthening Sunday as it approached the central Texas coast, with hurricane warnings reaching from High Island to Sabine Pass. The National Hurricane Center forecasts the storm to make landfall late Sunday or early Monday as a Category 1 storm with 85-mph winds. 

Meanwhile, in a rapid attribution study that compared regional climate conditions in the 1979 to 2001 period with conditions in the last two decades, researchers said global warming made Beryl’s wind and rain between 10 and 30 percent more intense.

Tropical storms that form in the region have been “significantly intensified by human-driven climate change,” said climate researcher Tommaso Alberti, with Italy’s National Institute of Geophysics and Vulcanology. “This means that, while we might see similar episodes with the same frequency, their intensity will be stronger, leading to catastrophic consequences for the vulnerable Caribbean islands.”

The study was done by an international research consortium called ClimaMeter, formed to provide a scientific framework for understanding extreme weather events in the context of human-caused warming. The group is funded by the European Union and the French National Centre for Scientific Research.

The research is a “clarion call for urgent adaptation and climate mitigation measures,” said researcher David Faranda, with the French National Centre for Scientific Research. “Intensifying hurricanes, coupled with sea-level rise, are expected to exacerbate the severity and frequency of such disasters in a warming climate.”

Hurricane experts have been warning for months that extremely high sea surface temperatures in the tropical Atlantic could contribute to a hyperactive hurricane season this year. Two days before Beryl formed, forecasters with the National Hurricane Center said environmental conditions were “unusually conducive for late June across the central and western tropical Atlantic.” 

On July 3, just a couple of days after forming, Beryl intensified rapidly to become a Category 4 hurricane, marking by far the earliest formation of a major hurricane in the Atlantic. Rapid hurricane intensification is part of a trend observed in recent climate research and predicted by climate scientists for more than 30 years. 

A 2023 study in Scientific Reports, for example, found tropical cyclone intensification rates were nearly 29 percent greater in the 2001 to 2022 period than in the 1971 to 1990 period. That study also found that the number of tropical storms that intensify from Category 1 to major hurricane status within 36 hours has more than doubled in the last 20 years. 

Reflecting research done in the past few decades, the U.S. National Climate Assessment concludes: “The intensity, frequency, and duration of North Atlantic hurricanes, as well as the frequency of the strongest hurricanes, have all increased since the early 1980s. Hurricane intensity and rainfall are projected to increase as the climate continues to warm.” 

Based on the trends, some researchers advocate for adding a Category 6 to the hurricane intensity scale, or adjusting the scale in other ways to highlight what could be previously unexpected threats. In 2021, the National Hurricane Center moved up the start of its official forecasting season by two weeks and made some changes to the hurricane naming system in response to the onslaught of hurricanes the previous year, which ended with the latest-ever formation of a Category 5 storm in the Atlantic, Iota, in mid-November 2020.

Along with destroying coastal and island communities, stronger storms also threaten ecosystems and biodiversity, including nesting seabird colonies. Before Beryl made landfall in Cancun, volunteers dug up and relocated thousands of sea turtle eggs from local beaches to prevent the nests from being flooded by storm surge. Sea turtles have evolved to adapt to hurricanes, of course, but unusually strong early season storms can wipe out entire generations at affected beaches, and if such storms are more frequent, they would threaten the viability of local populations.

Vulnerable Caribbean Islands

Hurricanes intensified by global warming have hit developing island states in the Caribbean especially hard. Beryl was no exception, leaving a trail of near-total devastation when it hit Carriacou, Grenada, on July 1 with sustained winds of 150 mph. Saint Vincent and the Grenadines as well as Union Island were also hit, and the storm’s winds and flooding had killed at least 22 people and caused $5 billion worth of damage as of July 5.

Beryl “left hundreds of thousands of residents without electrical power and caused extensive damages,” said Faranda. The storm magnified socio-economic disparities in these vulnerable Caribbean communities, “which bear limited responsibility for historical greenhouse gas emissions,” he added.

After crossing the islands, Beryl intensified even more on July 2, reaching Category 5 strength with 165-mph winds as it headed toward Jamaica. That made it the earliest Category 5 hurricane ever recorded in the Atlantic, all the more “remarkable, as it occurred in a region typically not conducive to such early-season hurricanes,” the authors of the new attribution study wrote.

After raking much of Jamaica with large waves and hurricane winds, Beryl weakened when shearing winds partly disrupted the system’s circulation. But it surprised hurricane experts again by unexpectedly resurging to Category 3 strength just before making its next landfall on Mexico’s Yucatán Peninsula, south of Cancun, as a Category 2 storm with 100-mph winds.

Some forecasts show the strongest winds and rain in the Houston region, along with storm surge into Galveston Bay. Both the official NHC forecast discussions and online comments by other hurricane experts warn that Beryl could rapidly intensify in the last few hours before landfall due to very warm ocean surface temperatures along the coast. The NHC specifically warned that “people should be preparing for the possibility of a category 2 hurricane landfall.”

The authors of the attribution study acknowledged that there are some uncertainties in their comparative approach to determining how global warming affected Hurricane Beryl because the storm was so unusual that there is not much to compare it to. 

“For this event, we have low confidence in the robustness of our approach given the available climate data, as the event is largely unique in the data record,” they wrote.

But their findings are consistent with other studies that all point to a rising danger from tropical systems. Even the conservative science assessment from the Intergovernmental Panel on Climate Change says that global warming has “increased observed precipitation, winds, and storm surge associated with some tropical cyclones, and there is evidence for an increase in the annual global proportion of Category 4 or 5 tropical cyclones in recent decades.”

In the Atlantic hurricane region, some studies suggest global warming is shifting large-scale wind patterns to steer more hurricanes toward the Northeast of the United States, raising the risk of catastrophic storms like Irene, in 2011, and Sandy, in 2012. 

Those climate model projections mesh closely with paleoclimate evidence from sediments and cave formations that indicate more prehistoric big tropical storms made landfall at the western edge of the Atlantic in the Northeastern U.S. rather than curving north and then northeast over open water, as many storms currently do. More climate heating means New England, for example, could face the threat of a Category 3 hurricane every decade, rather than once every two or three hundred years, according to the National Science Foundation.

There are also warning signs in the Pacific regions vulnerable to hurricanes and cyclones. Just last summer, millions of people in Southern California watched warily as Category 4 Hurricane Hilary made it nearly to San Diego before weakening over cooler waters prior to landfall. That storm’s size and intensity led the National Weather Service to issue a first-ever tropical storm warning for parts of Southern California.And the Hawaiian Islands could also face more hurricanes in the future, as global warming heats up the surface of the central Pacific Ocean. When Hurricane Lane passed near the islands in 2018, scientists considered it a warning for the region, noting that some studies project a doubling of hurricane activity in that sector by 2100 in a warming climate.