Recent US research suggests that the number of hurricanes and tropical cyclones experienced in the Atlantic and Pacific oceans will decrease as a result of global warming. At the same time there will be a slight increase in the intensity of these storms.

So fewer hurricanes but more severe when they appear.

These findings appear to be completely at odds with many other studies done on this topic, which, so far, have always indicated more storms in a warmer climate. So will man-made global warming really have a big impact on hurricane season? (Is there really man-made global warming?)

The obvious answer is that if the heat entering the global climate system increases, there will be more energy in the atmosphere, causing more evaporation from the oceans leading to heavy rain and stronger winds. However, if we have learned anything throughout the earth’s long history, it is that weather is predictably unpredictable.

Although the study projected that there would be fewer extreme weather events in the future, these storms are likely to be more powerful. So fewer hurricanes, but with a much bigger impact. A previous study by scientists showed a 4% increase in storm intensity for every 1°C (1.8°F) increase in sea surface temperature. But this most recent study suggests only a 1-2% increase.

One of the key components for hurricane formation is a sea surface temperature of 26.5 °C (79.7 °F) or higher. This allows a hurricane to form and feed much more easily. This is why hurricanes typically increase in intensity after moving from the slightly cooler waters of the Atlantic over the Florida Panhandle to the warmer waters of the Gulf of Mexico. Hurricane Katrina is a perfect example of a hurricane that increased in intensity as it passed over the Gulf, feeding on the warm ocean, before making landfall with a devastating impact on New Orleans.

In recent decades there has been an increase in the surface temperature of the tropical oceans of 0.5C (0.9F). This is believed to have been caused by the increase in global concentrations of greenhouse gases in the atmosphere.

Is all this man-made? Possibly, but a definitive answer cannot really be given as there is evidence both for and against man’s impact on the climate. One thing is for sure, man-made global warming has now become big global business! This has made me somewhat skeptical, although there is definitely a warming trend in the weather right now. However, whether this is anthropogenic in origin or stems from a different dynamic, eg solar production, is still up for debate. Natural weather variations, such as El Niño and La Niña, also have a large short-term impact on the earth’s weather and storm systems.

In the coming years there will be more and more models, studies and hypotheses about the climate, each one will be slightly different, some will be completely opposite to others! Only time will tell us the real answer, but in the meantime it won’t hurt all of us to reduce pollution on our planet, global warming or not, it’s not a good thing.