Disaster season is approaching and this year the world could see its first ever city-killing Category Six hurricane.

Thanks to global warming, extreme weather is becoming the norm. Last year was the hottest year on record and the first time ever that the entire year was 1.5C hotter than the pre-industrial temperature baseline set in Paris in 2015. This year is going to be worse.

Recent research has sounded the alarm on the possibility of hurricanes reaching the unprecedented Category Six intensities on the Saffir-Simpson scale.

A category six is the meteorological equivalent of “11” on Spinal Tap’s amplifier. Currently the scale only goes up to five for wind speeds of “70.5m/s or higher”. Storms have been known to touch temporarily on wind speeds of up to 82m/s, but technically these are still Category 5 hurricanes, as those speeds are not sustained. And even those do a lot of damage.

“Category Five: Catastrophic damage will occur. A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months,” according to the definition of a category five storm.

Scientists caution that as climate change accelerates and oceans warm, the conditions for extreme weather events become increasingly favourable. Warm seas feed energy into cyclones originating in Africa as they travel over the Atlantic Ocean before making landfall on the east coast of the Americas with devastating effect.

Last year the tourist resort of Acapulco literally got blown away after it was hit by its first ever Category Five hurricane laying waste to the city. Likewise, the subtropical storm Daniel ripped through Libya in September, killing over 11,000 in less than hour with a total of 34,000 missing. The ferocity of the storms that started in Spain was fuelled by unusually warm water in the Mediterranean Sea as the storm headed to Africa.

A study published in the journal Nature, led by atmospheric scientists at the University of Bristol, delved into the potential for hurricanes to escalate to Category Six this year. The research, utilising climate model simulations, found that hurricanes are becoming more intense and an inaugural Category Six storm is on the cards.

Lead author Dr. Cyril Morcrette said: "Our simulations suggest that hurricane intensities increase roughly by 1 category on the Saffir-Simpson scale for each 1°C increase in global mean surface temperature." The researchers' projections indicate that future storms could attain sustained winds exceeding 78m/s, classing them a Category Six.

Morcrette stressed the urgency of addressing climate change to prevent these city-killer storms appearing: "These numbers are concerning and underline the importance of continued efforts to reduce greenhouse gas [GHG] emissions and mitigate climate change."

The study paints a grim picture of the potential devastation such storms could unleash. Parameters for a Category Six hurricane include sustained wind speeds over 78m/s, central pressure dropping below 900 mbar, catastrophic impacts and complete building structural failures, as well as extreme coastal flooding reaching heights of 8m or more.

While Hurricane Wilma in 2005 holds the record for the strongest storm to date with 82m/s winds, it fell short of meeting the criteria for a Category Six designation. However, as ocean temperatures rise due to climate change, scientists anticipate a greater likelihood of storms reaching unprecedented intensities. Last year also saw the hottest sea temperatures on record, and this year has started with sea temperatures well above those in January of 2023.

“January ends with the highest Global average Sea Surface Temperature in observational history. Prepare for a lot of crazy weather in the pipeline,” tweeted Leon Simons, a climate observer.

January ends with the highest Global average Sea Surface Temperature in observational history

Dr. Savin Chandrasegaran, co-author of the study, underscored the role of warm ocean temperatures in fuelling hurricane intensity. And in the last two years the US East Coast has been hit by a string of increasingly powerful hurricanes during the disaster season.

Bermuda, New England and Atlantic Canada became jittery after a hurricane suddenly intensified last September to a Category Five but turned north and lost its power before it made landfall at the last minute.

"We are already seeing an increase in the proportion of hurricanes reaching Category Four and Five due to warming oceans. Our research suggests we could see unprecedented intensities in the future," he warned.