Like swarms of locusts devouring everything in their path, the wildfires that struck California’s fabled wine country and surrounding areas have left behind death and destruction on an unimaginable scale.

With no warning, the blazes began spreading rapidly on the evening of Sunday, Oct. 8th, and by the end of the week, there had been 31 confirmed deaths, over 400 people still missing, and 3,500 structures destroyed. In Santa Rosa, long considered safe from wildfires, whole neighborhoods went up in flames within minutes. An estimated 60,000 people were forced to flee or were evacuated from the fire-ravaged area.

All told, some 22 separate fires scorched 191,000 acres, or about 300 square miles. It is the second-deadliest wildfire in California since 1923. Adding to the misery were quirks of Mother Nature. The Diablo, a strong gusty wind prevalent in northern California, helped spread the conflagration. And while the arid region has recently recovered from a severe, years-long drought, the grasses that have grown back thanks to the much-needed precipitation enabled the fire to spread more rapidly.

Wildfires and the Environment

In addition to the dreadful loss of life, the wildfires, which are expected to last for several more weeks, have taken their toll on wildlife and air quality. Satellite images show a huge plume of smoke stretching from central California to northwest Nevada and into southern Oregon and Idaho. Sean Reffuse, an air quality analyst with the University of California at Davis, told USA Today that the fires have put 10,000 tons of particulate matter (PM), a leading cause of haze, into the air. He calculates that it would take about 35,000 on-road vehicles a year to produce that much PM pollution. Exposure to higher levels of PM have been associated with respiratory and cardiovascular problems.

At this writing, the cause of the wildfires remains unknown. Wildfires have been a scourge in California and other areas of the arid West for as long as anyone can remember. California’s dry climate and strong winds – Diablo in the north and Santa Anna in the south – are often a wildfire’s best friend.

Consequences of Bad Policies

The region is also dotted with huge national forests, which for decades were governed by disastrous fire-suppression policies. In forests, wildfires, usually caused by lightning, can be nature’s way of removing undergrowth before it has a chance to build up to dangerous levels. When these relatively small fires are suppressed, forests can become veritable tinder boxes. Even after enactment of the Healthy Forests Initiative in the last decade, a law that allows for the removal of dead and diseased trees in national forests, many of the lands managed by the U.S. Forest Service, are still at risk of igniting a conflagration.

What’s more, restrictive zoning laws in cities like San Francisco and San Jose have put home prices out of reach for people of upper-middle, middle, and lower income. Unable to afford homes in high-end urban areas, many people are forced to live in distant suburbs, which puts them closer to areas where fire are likely to break out.

Wildfires will always be with us. They come with the territory. But when policies are in place that create conditions that make forests ripe for wildfires or that force people to live in high-risk areas, don’t be surprised if disaster ensues.