Climate Change

What are hurricanes?

Hurricanes are atmospheric phenomena that are formed in tropical oceans where temperatures are relatively high, around 140°F – 180°F (60°C – 80°C).

These are caused by pressure changes and temperature differences, generating strong wind currents loaded with vaporized water. Tropical storms are formed first, however, when these winds rotate around a point or eye at speeds in excess of 73 mph, these are said to be hurricanes.

In recent years, some hurricanes have made landfall on U.S. shores, such as Hurricanes Ida and Ian, which reached the United States in 2021 and 2022, respectively.

Ida reached the United States in August 2021, as a category 4 with winds exceeding 150 miles per hour, one of the most severe atmospheric phenomena to hit the country since HurricaneKatrina (2004), leaving economic damages of around $75.25 billion.

The damage was caused mainly because Ida slowed as it reached the U.S. coast, moving northwestward at speeds of 10 miles per hour, according to the National Hurricane Center. This caused an increased impact in specific areas such as Louisiana, New York, Mississippi, New York, and New Jersey.

This behavior is not a common occurrence in hurricanes, however, over the last few decades, it has become a trend with most hurricanes, which is a concern for countries that are regularly affected by such atmospheric phenomena.

The aggravating factor of hurricanes: Climate change

Although the United States has experienced a number of hurricanes in recent years, this is not a trend that is considered normal. This is due to human causes: climate change.

Some scientists relate it directly to global warming generated by the emission of greenhouse gases that are causing an increase in the temperature of the seas and oceans. Despite constant progress in the area, there is no definite proof that changes in hurricane behavior are caused by global warming.

However, it is clear that changes in pre-existing patterns, such as frequency and intensity, have been caused by this increase in the temperature of planet Earth.

Recent research shows an increase in the number of hurricanes that tend to stall and slow down, a pattern different from what we have been seeing, causing severe rainfall damage and subsequent flooding, resulting in loss of life and economic loss during their passage.

How exactly are hurricanes changing?

Hurricanes have certain characteristics that differentiate one from another and that are important to take into account, such as their wind speed, the amount of water they hold, their precipitation, and the speed at which they move.

Among the main changes that we can register in the behavior of hurricanes during the last decades, we can note the following:

Increase in Wind Speed

Hurricanes have become more dangerous and a key factoraffecting their danger is the speed of their winds. This is mainly due to the increased evaporation of water. The greater the temperature difference in the atmosphere, the more energy hurricanes absorb, which in turn increases their wind speed.

Increase in Rain Fall

Due to the higher temperatures of the oceans, water evaporates in greater quantities. This water ends up generating hurricanes with more water being absorbed. Every degree increase in temperature allows the air to contain at least 7% more water.

In addition to winds, this is the most aggravating feature of hurricanes, as floods cause the most property damage and deaths, even more than strong winds.

All of this means that hurricanes and storms generate much more rain, which leads to greater flood damage. A clear example of this is the case of Ian, the hurricane

that hit the Florida coast in September 2022, causing catastrophic damage that made it the deadliest hurricane since the Labor Day hurricane of 1935. This is all due to the high amount of water it possessed.

Decrease in hurricane movement velocity

At the moment, scientists do not know the exact reason why hurricanes are moving at lower speeds. This, coupled with the large amount of water hurricanes hold, increases rainfall and flood damage.

Over the past few years, hurricane rainfall has increased as hurricanes have made landfall and their forward speeds have been reduced by about 17% compared to previous hurricanes.

Longer storm duration

A few years ago, hurricanes tended to lose intensity and degrade into storms or depressions, causing rain and winds that posed less of a threat. However, this factor has changed due also to rising ocean temperatures, which act as a fuel to increase the lifespan of hurricanes.

Increased likelihood of hurricanes and shortened intensification times

Hurricanes emerge from tropical storms when they intensify. Today, not only are depressions and storms more likely to develop into hurricanes, but the period in which this happens is shortening. Hurricanes are forming in a short period of time.

Hurricanes tend to intensify in warmer climates, which makes rising temperatures due to climate change an ideal situation for hurricane generation.

This increase in intensity could be defined by increases in speeds of more than 35 miles per hour in less than 24 hours. This may leave authorities helpless due to the reduced intensification time.

These shortened intensification times are a new feature of hurricane behavior but are becoming a common feature at least once per hurricane season.

Although it is not a certainty that there will be an increase in the number of hurricanes per season, it is crucial for governments to be prepared for any eventuality, as global warming has added uncertainty that could cause catastrophic damage by catching cities and towns unawares.