In the hottest year on record, the fingerprints of a changing climate in a warming world occurred in dozens of extreme weather events.
There would be no time without heat; heat is energy, and climate is an expression of that energy, of an atmosphere trying to balance itself.
But too much heat in the system pushes the limits of what's possible in the climate and pushes it toward extremes.
So perhaps it's no surprise that this year's record heat has been a “through line” into many of 2023's most brutal weather events, Kristina Dahl, a climate scientist at the Union of Concerned Scientists, told CNN .
“Climate change influences our climate on Earth every day,” Dahl said. “In my opinion, the burden of proof now is to show that climate change did not influence an event, because it clearly influences everything around us.”
This year's extreme weather events are not unique – but a sign of things to come.
“These types of events will continue to become more frequent and more severe if we continue to warm the planet,” explained Dahl.
These are just a few of 2023's most notable examples of what extreme weather on a warming planet could look like.
Unusual rapid intensification
The record heat was not just in the air, but also in the oceans, which absorb most of Earth's excess heat.
“Sea surface temperatures were much warmer than in any previous year on record,” Dahl cited.
Warm water acts as food for storms, and the unusually warm ocean water in 2023 not only created more storms in the Atlantic, counteracting the storm-dampening effects of an intensified El Niño, but also fueled the explosive strengthening of storms that formed in Worldwide.
This explosive strengthening, known as rapid intensification, is becoming more likely as the atmosphere warms.
A cluster of 12 tropical cyclones in the Atlantic and Eastern Pacific ocean basins rapidly intensified in 2023.
Lee was the strongest Atlantic hurricane this season and peaked as a rare open-ocean Category 5 hurricane in September after its winds were strengthened to an incredible 136 km/h in 24 hours.
The explosion made Lee the third-fastest intensifying storm ever recorded in the Atlantic.
Idalia, the only hurricane to make landfall in the US this year, was yet another example of the more frequent rapid intensification of storms.
The storm briefly reached Category 4 status before making landfall in Florida's Big Bend region as a Category 3 hurricane — the strongest storm to hit the area in more than 125 years.
Eastern Pacific Hurricane Otis was the most extreme example of rapid strengthening in any of the basins this year.
Otis's winds surprisingly increased to 185 km/h in the 24 hours before its devastating Category 5 arrival in Acapulco, Mexico, in October.
Otis was the strongest Pacific storm to hit Mexico and came just two weeks after Category 4 Hurricane Lidia — also a rapid intensifier — made landfall just south of Puerto Vallarta as another of the Pacific's strongest storms.
Rapid intensification also helped Hurricane Hilary maintain enough strength to move across California as a tropical storm – the state's first since 1997.
Hilary unleashed a deluge that interrupted the tropical rains recorded in some states and that caused extreme flooding that remained for months in one of the driest places on Earth.
A historic tragedy in a year of unusual wildfire behavior
Unusual wildfire behavior marked the year, both where fires started and where they didn't.
Wildfires typically burn 7 to 8 million acres of land each year in the U.S., but have only charred 2.6 million acres in 2023, statistics from the National Interagency Fire Center show.
That's partly due to a soggy start to the year in the typically scorching West, which has kept wildfires to a minimum after years of destruction.
One season doesn't create a trend, and as the world warms, wildfires become more frequent and severe — particularly in the West, the latest National Climate Assessment notes.
Still, the season proved deadly and destructive, as intense heat combined with a lack of rain dried out the soil and left typically humid parts of the U.S. and much of Canada vulnerable to fires.
The tragedy hit the island of Maui, Hawaii, in August.
The wind-driven flames surged so quickly through drought-parched invasive grasses, swallowing everything in their path, that some people fleeing for their lives had no choice but to jump into the Pacific Ocean.
Many were unable to escape and the Lahaina fire became the deadliest on North American soil in more than 100 years.
Louisiana is one of the rainiest states in the US, but after a summer of endless heat, no tropical systems and little rain, the soil turned to flammable material.
The peak was reached in November, when 75% of the state was in exceptional drought – the largest such area in state history.
As a result, the state suffered one of its worst fire seasons in decades, according to data provided to CNN by the Louisiana Department of Agriculture and Forestry.
Fires in the southern half of the state continued into the fall, and their smoke fueled the “super haze” that caused a deadly pileup near New Orleans.
Fires also affected much of the US, even when it wasn't hot there.
Canada's worst wildfire season on record has burned an area roughly the size of North Dakota and sent clouds of toxic smoke from its numerous massive fires across the U.S. and even Europe.
Smoke blocked out the sun and caused air quality levels to plummet in June across the Northeast of the country.
Apocalyptic, orange skies swallowed New York City as the city briefly had the worst air pollution levels in the world.
Hottest month for any US city in “heat hell” summer
Heat records were broken this summer in the Northern Hemisphere. In the US, heat reached the south and central parts of the country.
The heat index exceeded 54ºC in Kansas, New Orleans and reached the highest temperature recorded – 40ºC – with much of Texas and Florida experiencing exceptionally prolonged extreme heat.
But one city was emblematic of an extreme summer with heat that scientists called “virtually impossible” without human-caused climate change: Phoenix.
July in Phoenix was the hottest on record for any US city.
The city's average temperature for the month reached a surprising 39.2ºC, after brutally hot days and nights of record heat.
Phoenix has endured an unprecedented 31 consecutive days with high temperatures at or above 100 degrees Fahrenheit.
The heat took a terrible toll.
At least 579 people died in 2023 from heat-related causes in Maricopa County, where Phoenix is located, in what was the deadliest year for heat since the county began monitoring in 2003.
Days when high temperatures exceed 100 degrees are becoming more common in many major U.S. cities as global temperatures rise.
But Phoenix recorded the biggest increase of them all. The city has an average of 18 more days above 37ºC each year, compared to historical averages. This translates to around 111 days above 37ºC each year.
Floods kill thousands
Storm Daniel caused deadly floods in Greece, Turkey and Bulgaria in September, before crossing the Mediterranean Sea and arriving in Libya.
Carried by the warm waters of the Mediterranean, Daniel became a “medicane” – a storm with characteristics similar to hurricanes and typhoons.
The storm caused torrential rain across Libya and one city recorded 406 mm of rain in just 24 hours. As a result, massive floods occurred, killing around 4,000 people.
The city of Derna was the hardest hit. The floods broke two dams and unleashed a huge wave of water that swept away much of the city center.
The World Climate Attribution initiative – a team of scientists analyzing the role of climate change following extreme weather events – found that planet-warming pollution made deadly rains in Libya up to 50 times more likely and 50% worse.
It doesn't take a medicine or even a tropical system to trigger devastating floods in a warming world.
As the atmosphere continues to warm, it is able to absorb more moisture like a towel and then expel it in the form of more extreme bursts of torrential rain.
This scenario occurred several times in the USA: in California in January and March; in July in Vermont's capital Montpelier and northern New York.
*CNN's Laura Paddison and Nadeen Ebrahim contributed to this report
Source: CNN Brasil
Bruce Belcher is a seasoned author with over 5 years of experience in world news. He writes for online news websites and provides in-depth analysis on the world stock market. Bruce is known for his insightful perspectives and commitment to keeping the public informed.
