The Briefing

• An average of 70,000 wildfires blaze through the U.S. each year
• These fires destroy approximately 5.8 million acres of land on a yearly basis
• Over 43,000 fires have started across the U.S., burning 5 million acres of land as of Sept 3, 2021

30 Years of Wildfires in America

This summer, record-breaking droughts and relentless heat waves have fueled disastrous wildfires across the United States. It’s gotten so bad, the state of California has decided to shut down all national forests for two weeks to stop the spread.

But how disastrous has this year been compared to previous years? This graphic gives a historical look at the number of wildfires in America that have occurred each year since 1990, and the acres of forest land scorched during that period.

Total Wildland Fires and Acres from 1990 to 2020

In the U.S., an average of 70,000 wildfires burn through 5.8 million acres of land each year. But some years have been worse than others.

*note: 2021 figures as of September 3, 2021

One particularly bad year was 2006, which had over 96,000 fires and destroyed 9.9 million acres of land across the country. It was the year of the Esperanza Fire in California, which burned 40,000 acres and cost $9 million in damages.

2015 was also a devastating year, with over 10.1 million acres destroyed across the country–the worst year on record, in terms of acres burned.

Climate Change’s Role in Wildfires

Wildfires are only expected to worsen in the near future since warmer temperatures and drier climates allow the fires to grow quickly and intensely.

We’re already starting to see climate change impact the wildfire season. For instance, autumn is usually peak wildfire season for California, but this year, one of the largest fires on record started in mid-July, and is still burning as of the date of publication.

Editor’s note, September 20, 2021: In the post above, we said that California closed downed down all national parks for two weeks, starting August 31st. In fact, they closed down all national forests.

Where does this data come from?

Source: National Interagency Fire Center
Details: 2004 fires and acres do not include state lands for North Carolina.

The Briefing

• Storms are categorized by their wind speed. Any storm with winds stronger than 111 miles per hour (mph) is considered a major hurricane
• This year’s Hurricane Ida is one of the strongest hurricanes on record to hit the U.S. mainland, with winds reaching up to 150 mph

Explained: The Typical Atlantic Hurricane Season

On August 29, 2021, Hurricane Ida hurled into the state of Louisiana at rapid speed. With winds of 150 mph, preliminary reports believe it’s the fifth strongest hurricane to ever hit the U.S. mainland.

As research shows, Hurricane Ida’s impact hit right at the peak of the Atlantic hurricane season. Here’s a brief explainer on the basics of hurricanes, how storms are classified, and what a typical storm season looks like in the Atlantic Basin.

Let’s dive in.

Classifying a Storm

Hurricanes are intense tropical storms that are classified by their wind speed. What’s the difference between a hurricane, a typhoon, and a cyclone? They’re essentially the same thing, but are named differently based on their location:

• Hurricane is used for storms that formed in the North Atlantic, central North Pacific, and eastern North Pacific (impacting countries like the U.S.)
• Typhoon is used for storms in the Northwest Pacific (impacting countries like Japan)
• Tropical Cyclone is used for storms in the South Pacific and Indian Ocean (impacting countries like Fiji and India)

Since we’re focusing on the Atlantic, we’ll be using the term hurricane and/or storm throughout the rest of this article.

A storm needs to reach a certain wind speed before it gets classified as a hurricane. Storms with wind speeds of:

• <73 mph are considered Tropical Storms
• 74-110 mph winds are considered Hurricanes
• 111 mph+ winds are considered Major Hurricanes

Breaking Down the Atlantic Hurricane Season

Generally, Hurricanes form in the warm ocean waters in the central Atlantic and Gulf of Mexico, following westward trade winds and curving up towards the North American mainland. Hurricanes are formed when these specific elements come into play:

• A pre-existing weather disturbance such as a tropical wave
• Water at least 80ºF (27ºC) with a depth of at least 50 meters
• Thunderstorm activity
• Low wind shear (too much wind can remove the heat and moisture hurricanes use for fuel)

The Atlantic hurricane season technically lasts six months, beginning on June 1st and ending in late November. However, 85% of activity happens between August, September, and October.

Each subregion in the Atlantic has its own unique climatology, which means peak seasons can vary from place to place—for example, south Florida sees the most hurricanes in October, while the entire Atlantic Basin’s peak season is early-to-mid September.

Climate Change and Hurricanes

According to the Center of Climate Change and Energy Solutions, it’s unclear whether climate change will increase the number of hurricanes per year.

However, research indicates that warmer weather and high ocean temperatures will most likely lead to more intense storms, ultimately causing more damage and devastation.

» Want to learn more about climate change? Here’s an article on The Paris Agreement: Is The World’s Climate Action Plan on Track?

Where does this data come from?

Source:Brian McNoldy, University of Miami Rosenstiel School of Marine and Atmospheric Science