SOURCE: Washington Post

DATE: July 30, 2017

SNIP: Firefighters are waging war against 17 wildfires that cover 200,000 acres in California this week. Front-line dispatches suggest that, at least at times, they’ve lost the battle. The bodies of two children were found under a wet blanket with the remains of their great-grandmother hovering over them. Three firefighters and one bulldozer operator are dead. More than 700 homes have burned to the ground.

Crews have struggled, at least in part, because they have never seen fires behave like this before.

“What we’re seeing in California right now is more destructive, larger fires burning at rates that we have historically never seen,” Jonathan Cox, a Cal Fire spokesman, told CNN on Monday morning.

Several specific conditions are feeding the inferno. Afternoon temperatures have peaked in the triple digits around Redding, Calif., since early last week.

The dew point — a measure of how much moisture is in the air — dropped precipitously through Thursday afternoon until humidity was 10 percent as the temperature reached 110 degrees.

On top of that, the soil in Northern California is exceptionally dry. A hotter-than-average summer and a very dry winter have led to tinder-dry vegetation. When it ends Tuesday, this month will become Redding’s hottest July on record, with an average temperature of 86.7 degrees. The energy release component, or how much fuel is available for the fire, is at the highest it has been around Redding since at least 1979.

As Earth’s average temperature warms because of human-made climate change, topsoil will continue to dry out, according to the 2017 National Climate Assessment.

“The incidence of large forest fires in the western United States and Alaska has increased since the early 1980s,” the assessment concluded with high confidence, “and is projected to further increase in those regions as the climate warms.”