This video of a wildfire engulfing a forest in seconds is terrifying

In ideal conditions, wildfires move quickly.

When it's hot, dry, and there's a lot of fuel, it can take just seconds for them to spread. In fact, wildfires have scorched more than 8.9 million acres of land already this year - up 1.2 million acres from this time last week, according to data from the National Interagency Fire Center (NIFC).

This video, posted in 2007, shows just how frighteningly fast fires can move. It begins with a quiet, idyllic scene, but it's not long until the camera is engulfed in flames.

At first glance, the video looks like a time lapse, but the timer shows that just 15 seconds has elapsed. By 20 seconds in, the screen is just a wall of flames as the temperature counter peaks at 900 degrees Celsius.

Just 40 seconds in, you can see how far the fire has spread.

The video provides a vivid illustration of how quickly fires can move. Seeing it unfold up-close, it's easy to understand how the number of acres consumed by wildfires can skyrocket at times like this, when the conditions for spread are just right. The all-time record is 9.8 million acres in 2006, according to the NIFC.

More wildfires mean more firefighters killed or injured fighting them.

Three firefighters died fighting one of the 11 fires raging in Washington, CNN reports. According to the Washington Post, "some 30,000 firefighters and support staff are now fighting fires across the United States," the largest number of firefighters assembled in the past 15 years.

As climate change leads to hotter and drier temperatures, we're likely to see wildfires that are more serious and more unpredictable. Former firefighter Nicky Sundt warns in a Weather Channel video that massive wildfires and longer fire seasons will become the new normal.

"In the 70s and 80s, the fires weren't as big, they weren't as intense and the fire seasons were shorter," Sundt, now the director of climate change science and policy integration for the World Wildlife Fund, says in a video for the Weather Channel. "As the climate has warmed, fires have gotten a lot bigger, and they're burning hotter, and their behavior is more erratic and more extreme."

Many experts and officials agree with him. A recent study published in the journal Nature found that climate change may be contributing to wildfires around the world that burn more land and last longer.

These numbers may seem abstract, but for firefighters and residents in vulnerable areas, it's very real.

The 2014 fire season was full of "people wandering through what used to be their neighborhoods [and] basically all they escaped with is the clothes on their backs," Sundt said. "This is the really human cost of the changes that we're seeing. It isn't simply burning trees."

Watch the whole video below.