As Hurricane Florence zeroes in on the south eastern US, scientists are warning that climate change is exacerbating the effect of tropical storms.

The powerful Category 4 Atlantic weather-front is slow moving, an increasingly common phenomenon that poses a different manner of threat to states in its path.

In the event that Florence stalls or comes to a halt altogether over land, it has the potential to deposit catastrophic quantities of rainwater, posing a risk of severe flash flooding.

While the high winds and waves generated by faster storms moving inland from the ocean pose a significant danger to human life and property, the effect of heavy rain can be just as devastating, if not more so.

When Hurricane Harvey hit in August 2017, it dropped 60 inches of rain over Houston, Texas, flooding the streets, leaving 93 dead and hundreds more having to be rescued by boat, causing millions of dollars-worth of damage.

James Kossin of the National Oceanic and Atmospheric Administration published a study in the journal Nature in June suggesting that slow-moving tropical cyclones, which would include those like Florence and Harvey, have become more common over the last 70 years, dropping in speed by 10 per cent in that time.

According to Mr Kossin, global warming as a result of man-made air pollution is causing the poles to become warmer, which in turn reduces the difference in temperature between the Arctic and Antarctic and the equator, altering atmospheric pressure and slowing down the whipping currents of wind that pass between them and drive hurricanes.

The weakening of these winds has also been blamed for the stalling that gave rise to this summer’s UK heatwave.

Mr Kossin’s findings echoed those published by the American Meteorological Society a year earlier, studying the passage of 22 hurricanes since 2004 and concluding that future storms would drift more slowly and pose their greatest threat to man from heavy downpours.

Slower storms also mean they are likely to linger for longer, increasing the likelihood of property damage.

“If the wind’s blowing very hard against the structure and it blows a few more hours than it would have, the likelihood of knocking that structure down increases,” Mr Kossim told NPR.

“You get more rainfall, you get more wind damage. You also get more storm surge. Slower storms will have a tendency to push a larger wall of water in front of them. So it’s really a triple threat.”

Warmer air and water as a result of heat being trapped in the atmosphere by greenhouse gases – present as a result of our burning fossil fuels in cars, power plants and aeroplanes – also increases the amount of vapour a storm can carry, meaning even more rain.

This is thought to have fuelled the devastation Harvey caused, said scientists from the National Center for Atmospheric Research (NCAR), who wrote in the journal Earth’s Future in May that the Gulf of Mexico was then experiencing abnormally high ocean temperatures of 30C.

“Record high ocean heat values not only increased the fuel available to sustain and intensify Harvey but also increased its flooding rains on land,” NCAR climate scientist Kevin Trenberth observed.

Hurricane Florence hits the US East Coast Show all 20 1 /20 Hurricane Florence hits the US East Coast Hurricane Florence hits the US East Coast Barmen protect their business from the storm and the opportunists Getty Hurricane Florence hits the US East Coast Many supplies have run out as Hurricane Florence approaches in Nichols, South Carolina AP Hurricane Florence hits the US East Coast Hurricane Florence seen from space on September 12 AP Hurricane Florence hits the US East Coast Students of East Carolina University's Coastal Storms class use anemometers to measure wind speeds at Union Point Park in New Bern, North Carolina AP Hurricane Florence hits the US East Coast Rescue workers are on the scene in James City, North Carolina Getty Hurricane Florence hits the US East Coast Sixteen hours before Florence even hits land, the Neuse River bursts its banks and floods New Bern, North Carolina Alamy Hurricane Florence hits the US East Coast Volunteer rescue workers help three children out of their flooded home in James City, North Carolina Getty Hurricane Florence hits the US East Coast A boardwalk is damaged in Atlantic Beach on North Carolina's coast Getty Hurricane Florence hits the US East Coast Union Point Park in New Bern is closed Reuters Hurricane Florence hits the US East Coast A child sits in Conway High School, which is being used as an evacuation centre in South Carolina AFP/Getty Hurricane Florence hits the US East Coast Locals voice their disapproval of the storm in Atlantic Beach, North Carolina Getty Hurricane Florence hits the US East Coast Volunteer rescue workers help children from their flooded home in James City Getty Hurricane Florence hits the US East Coast A man floats down his street in a metal tub after the Neuse River burst its banks in New Bern, North Carolina Getty Hurricane Florence hits the US East Coast Electric lines are affected in Wilmington, North Carolina Alamy Hurricane Florence hits the US East Coast Floods in New Bern, North Carolina as Florence approaches Alamy Hurricane Florence hits the US East Coast Waves crash over a pier on Atlantic Beach in North Carolina as Hurricane Florence approaches AP Hurricane Florence hits the US East Coast Hurricane Florence is seen from the International Space Station as it churns in the Atlantic Ocean towards the east coast of the US NASA/Reuters Hurricane Florence hits the US East Coast This NOAA/RAMMB satellite image taken on September 10, 2018, shows Hurricane Florence off the US' east coast in the Atantic Ocean AFP/Getty Hurricane Florence hits the US East Coast In this NOAA satellite handout image, Hurricane Florence is shown travelling west and gaining strength in the Atlantic Ocean southeast of Bermuda on September 10, 2018 Getty Hurricane Florence hits the US East Coast Firefighters rescue people by boat in New Bern, North Carolina Getty

Harvey was able to feed off the heat stored in the 930-mile wide basin as it headed north towards Texas, its winds strafing the surface and picking up water through evaporation, a process requiring heat and one therefore encouraged by the unusually warm temperatures of the upper ocean.

“The implication is that the warmer oceans increased the risk of greater hurricane intensity and duration,” Mr Trenberth said.

Whereas climate scientists were once much more reluctant to say for certain that global warming was directly responsible for causing an upsurge in extreme weather events, they have become increasingly emboldened to do so in recent years, under the influence of American geophysicist Michael E Mann and others.