by National weather analysts released their “list of billion-dollar disasters” for 2023 on Jan. 9, just as 2024 was getting off to a fierce start. A blizzard was hitting the Plains and Midwest, and the South and East faced flooding risks from extreme downpours.
The United States set a nasty record for weather and climate disasters in 2023, with 28 disasters exceeding $1 billion in damage each.
While it wasn’t the most expensive year overall (the costliest years included multiple hurricanes), it had the highest number of storms, floods, droughts and billion-dollar fires of any year since counting began in 1980, with six more than anyone else. year, taking into account inflation.
The costliest disaster of the year began with an unprecedented heat wave that hit Texas for weeks over the summer and then spread to the South and Midwest, helping to fuel a destructive drought. Extreme heat and lack of rain dried out fields, forced ranchers to sell livestock and restricted trade on the Mississippi River, causing $500 million in damage, according to conservative estimates by the National Oceanic and Atmospheric Administration.
Extreme dryness in Hawaii contributed to another multibillion-dollar disaster by sparking devastating wildfires that destroyed Lahaina, Hawaii, in August.
Other billion-dollar disasters included Hurricane Idalia, which hit Florida in August; flooding in the Northeast and California; and nearly two dozen other severe storms across the country. States in a swath from Texas to Ohio were hit by multiple billion-dollar storms.
El Niño played a role in some of these disasters, but the root of the world’s increasingly frequent extreme heat and weather is global warming. The year 2023 was the warmest year on record globally and the fifth warmest in the US.
I am an atmospheric scientist who studies climate change. Here’s a quick look at what global warming has to do with wildfires, storms and other weather and climate disasters.
Dangerous heat waves and devastating wildfires
When greenhouse gases, such as carbon dioxide from vehicles and power plants, build up in the atmosphere, they act as a thermal blanket, warming the planet.
These gases let in high-energy solar radiation while absorbing outgoing low-energy radiation as heat from the Earth. The energy imbalance at the Earth’s surface gradually increases the surface temperature of the land and oceans.
The most direct consequence of this warming is that there will be more days with abnormally high temperatures, as occurred in much of the country in 2023.
Phoenix spent 30 days with daily high temperatures of 110 F (43.3 C) or higher and recorded its highest overnight minimum temperature, and temperatures on July 19 never fell below 97 F (36.1 C).
Although heat waves are the result of climate fluctuations, global warming has raised the baseline, making heat waves more frequent, more intense and longer lasting.
That heat also fuels forest fires.
Increased evaporation removes more moisture from the soil, drying out soil, grasses and other organic materials, creating favorable conditions for wildfires. All it takes is a lightning strike or a spark from a power line to start a fire.
How global warming fuels extreme storms
As more heat is stored as energy in the atmosphere and oceans, not only does the temperature increase, but the amount of water vapor in the atmosphere can also increase.
When that water vapor condenses into a liquid and falls as rain, it releases a large amount of energy. This is called latent heat and is the primary fuel for all storm systems. When temperatures are higher and the atmosphere has more moisture, that extra energy can fuel stronger, longer-lasting storms.
Tropical storms are also fueled by latent heat from warm ocean water. That’s why they only form when the sea surface temperature reaches a critical level of around 80 F (27 C).
With the ocean absorbing 90% of the excess heat due to global warming, there has been a significant increase in global sea surface temperature, including record levels in 2023.
Higher sea surface temperatures can lead to stronger hurricanes, longer hurricane seasons, and more rapid intensification of tropical storms.
Cold waves also have connections to global warming
It may seem counterintuitive, but global warming can also contribute to cold snaps in the United States. That is because it alters the general circulation of the Earth’s atmosphere.
Earth’s atmosphere constantly moves in large-scale circulation patterns in the form of near-surface wind belts, such as trade winds, and upper-level jet streams. These patterns are caused by the temperature difference between the polar and equatorial regions.
As the Earth warms, the polar regions warm more than twice as fast as the equator. This can change weather patterns and cause extreme events in unexpected places. Anyone who has experienced a “polar vortex event” knows what it feels like when the jet stream descends southward, bringing frigid Arctic air and winter storms, even though winters are generally warmer.
In short, a warmer world is a more violent world, and additional heat fuels increasingly extreme weather events.
This article, originally published on December 19, 2023, was updated on January 9, 2024 with the NOAA disaster list.
This article is republished from The Conversation, an independent, nonprofit news organization bringing you trusted data and analysis to help you understand our complex world. The Conversation is trusted news from experts. Try our free newsletters.
It was written by: Shuang-Ye Wu, University of Dayton.
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Shuang-Ye Wu does not work for, consult with, own shares in, or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond her academic appointment.
