Explainer: How climate change is fueling hurricanes

STORY: Is climate change affecting hurricanes?

According to scientists - yes, climate change is making hurricanes wetter, windier and altogether more intense.

The ocean absorbs a lot of the atmospheric heat, much of it contained near the water’s surface.

This surface heat fuels a storm's intensity and powers stronger winds.

Our planet has already warmed 1.1 degrees Celsius, or 34 degrees Fahrenheit, above the preindustrial average.

Scientists at the U.S. National Oceanic and Atmospheric Administration expect that at 2 degrees Celsius of warming – that’s 36 Fahrenheit – hurricane wind speeds could increase by up to 10%.

They also project the proportion of hurricanes that reach the most intense levels — that’s Category 4 or 5 — could rise by about 10% this century.

A warmer atmosphere can hold more moisture, and water vapor will build up until clouds break, sending down heavy rain.

So, the warming planet is also upping the amount of rainfall delivered by a storm.

During the 2020 Atlantic hurricane season — one of the most active on record — climate change boosted hourly rainfall rates in hurricane-force storms - by up to 11%.

That’s according to an April 2022 study in the journal, Nature Communications.

There’s also evidence it’s also causing storms to travel more slowly, meaning they can dump more water in one place.

Climate change seems to be shifting the hurricane season and how far they go too.

In recent years, hurricanes, which are storms with wind speeds that reach at least 74 miles per hour, are reaching peak intensity - and sweeping farther north than in the past.

Scientists say, that shift may be related to rising global air and ocean temperatures.

This trend is worrying for mid-latitude cities such as New York, Boston, Beijing, and Tokyo, because their infrastructure is not prepared for such storms.

Hurricane Sandy was only a Category 1 storm when it hit the Northeastern Seaboard in 2012.

But it was the fourth costliest U.S. hurricane on record, causing $81 billion in losses.

As for the typical hurricane "season", that’s been changing too, as warming creates conditions conducive to storms in more months of the year.

In North America, the season is largely from June through November, peaking in September.

But a study recently published in Nature Communications showed, the first named storms to make U.S. landfall are nudging into May - more than three weeks earlier than they did in 1900.

The same trend appears to be playing out across the world in Asia's Bay of Bengal.

Since 2013, cyclones there have been forming earlier than usual - in April and May - ahead of the summer monsoon, according to a November 2021 study in Scientific Reports.

Hurricanes are called “cyclones” when they emerge over the Indian Ocean and South Pacific, and “typhoons” when they form over East Asian waters.