Hurricane Irma: why have there been so many destructive hurricanes and will there be more in the future? We asked the experts

What is causing these large hurricanes?

Julian Heming, the Met Office's tropical prediction scientist, told The Telegraph about the reasons Irma is such a large hurricane.

"Irma is a powerful hurricane because all the characteristics required to produce an intense hurricane in the Atlantic are coinciding:

• Sea surface temperatures under Irma are 1 to 1.5°C higher than the average for this time of year providing abundant moisture and warmth.
• The wind shear (change in wind with height) is low, meaning air can flow in up and out of the hurricane very efficiently, thus promoting intensification.
• There are no drying influences at present, such as pockets of Saharan dust which sometimes drift out over the Atlantic.
• Irma is moving fast enough to prevent cool water up-welled under the hurricane from having any impact on the continued feed of warm, moist air into the hurricane.
• Up until now there has been no interaction with large land masses that might disrupt intensification due to cutting off the moisture supply."

Why is it happening now?

The Met Office said that this is not totally unexpected and we have seen hurricanes of this magnitude in the past.

Mr Heming said: "It is worth pointing out that it is the peak of the hurricane season, so having hurricanes in this region now is not unexpected.

"Having three simultaneous hurricanes in the Atlantic region does not happen every year, but has been recorded several times before in the last 50 years: 1967, 1980, 1995, 1998, 2010.

"The North Atlantic hurricane season runs from June-November, with peak activity during August-October. During peak season around 96% of all Atlantic major hurricanes (categories 3, 4 and 5 on the Saffir-Simpson Hurricane wind scale) occur."

Is it because of climate change?

Richard Allan, the Professor of Climate Science at the University of Reading, told The Telegraph he believes the hurricanes we have seen are made worse by climate change.

He said that particularly strong seasonal warming this year has made conditions ripe for a hurricane: "Hurricanes, or tropical cyclones, require a set of atmospheric ingredients to form. Warm upper ocean water provides the most vital hurricane fodder - energy and water. But changes in wind and moisture with altitude are also key and the rotation of the Earth increasingly spins these storms up as they travel away from the equator. Especially strong seasonal warming this year combined with the other factors mentioned, partly relating to natural ocean fluctuations, have made conditions ripe for tropical cyclones to form in the Atlantic."

Dr Allan then explained that climate change can exacerbate this: "While weather explains the formation and track of these tropical beasts, additional heating due to emissions of greenhouse gases from human activities will inevitably make them more deadly. Extra energy from warmer waters increases the intensity of the winds in the strongest cyclones while a warmer atmosphere is able to suck in greater quantities of moisture which is dumped as more intense rainfall.

"Rising sea level due to oceans expanding as they warm and more ice melt from glaciers and ice sheets on land add to the size of ocean storm surges which can devastate coastal regions, including low lying islands. So while the fickle nature of the atmosphere and ocean have generated deadly storms this year, their impacts have been amplified by human-caused climate change."

Dr Sally Brown, Senior Research Fellow at the University of Southampton, said we can't be sure how much of an effect climate change is having on hurricanes.

She said; "How much climate change is involved in these hurricanes and their impacts is uncertain and requires study. Repeated studies to date have indicated that small islands are likely to have high levels of vulnerability to extreme events, such as Hurricane Irma, and suffer most in the aftermath. Apart from the immediate damage, flooding can have long-term effects, such as on water resources, soil salinisation affecting crops, or longer term stress related health effects on the population."

Professor Myles Allen, Professor of Geosystem Science at the University of Oxford, said he believes this is almost definitely due to climate change.

He explained:“As yet another hurricane barrels into the Caribbean, with extreme precipitation and the impacts of storm surges both exacerbated by past greenhouse gas emissions, we must begin to ask ‘how long can we expect taxpayers and those in the path of the storms to foot the entire bill for the impacts of climate change?’

“In a paper published today in the journal Climatic Change, we show that nearly 30% of global sea level rise from 1880 to 2010 can be traced to products sold by just 90 large corporations. We need to start a conversation about whether it makes sense to exempt companies selling products that cause greenhouse gas emissions from all liability for the consequences of their use. As we found in 2008, giving companies unlimited license to make private profits while society underwrites the risk ends badly for everyone.”

Is it likely to happen more frequently in the future?

The Met Office said it is uncertain whether this will happen more frequently, and that models give conflicting answers.

Mr Heming said: "There is much debate about the influence of climate change on hurricanes in the Atlantic. The latest research suggests that there may be an increase in tropical cyclone intensity in the future, under continued global warming. However, the models also indicate that tropical cyclone frequency will either remain unchanged or decrease."

Dr Allan predicted that warm coastal areas can expect more of these in the future, due to climate change.

He said: "There will be a continued threat to warm, tropical coasts from these events in the future. While there is not clear evidence to suggest an increase in the frequency of all tropical cyclones in the future, warming of the planet will generate more intense rainfall, stronger winds and more massive storm surges when intense tropical cyclones form and it is expected that there will be more super-charged tropical cyclones or Hurricanes as the planet continues to heat up."

Dr James Baldini, Reader in Earth Sciences at Durham University, said these hurricanes could give us a worrying glimpse into the future of weather.

He said: “Just like one blizzard does not discount the reality of global warming, one extremely powerful hurricane does not define a trend towards more powerful storms. However, Hurricane Irma and Hurricane Harvey fit within the long-term trend toward fewer but increasingly powerful hurricanes, a direct result of rising North Atlantic sea surface temperatures under global warming. It is worrying to consider that unless greenhouse gas emissions are actively curbed, these types of storms may represent the new ‘normal’ in the future.”