The National Interagency Fire Center in Boise, Idaho, has declared that the country is already at a level Five Alert, the earliest that this level has ever been reached. This means that the fires have the potential to exhaust all available Federal firefighters and fire equipment. Level Five alerts usually do not occur until late in the fire season in August.

Various factors fuel the growing fires, including human-caused climate changes and more people visiting and building in wilderness areas. The year-long drought, persistent heat, and the lowering of the water table contribute to the growing fire risk.

Some fires are directly caused by humans, either accidentally or on purpose. Geologists Jane Nielson and Howard Wilshire write, "Fires lit by chainsaws, off-road vehicles, careless campers, cigarettes tossed out of car windows, and other human agency are more frequent and widespread in many areas than those set naturally by lightning."

The 15,000-acre wildfire burning now near Yosemite National Park in California seems to have been set by Marines, during a practice campfire. Another fire seems to have been set by a lost hiker lighting a signal fire. In Yuba County, California, a fire was set by high winds blowing power lines into a tree.

Fires, of course, are natural phenomenon. Though people like to use fire's energy, they don't appreciate fires when they burn their properties, spoil their views, or harm humans. Because of our relative success controlling nature, humans have gotten the idea that we are in charge. But this year's fire season, which has just started, could challenge that illusion.

San Francisco firefighter Michael Castagnollo explains that "fire is a natural part of our environment. Humans want to inhabit the interface of urban and wilderness areas, which is where most of the problems occur.