Charred landscapes, smoke-filled skies and, in some cases, shuttered national park lodges are becoming the new norm in the western United States. Why is this happening? In Land On Fire, Gary Ferguson provides a course on wildfire in a West made drier, hotter, and more combustible by climate change.

The ramifications are seen on the Internet, your television, and in newspapers and magazines. Yosemite Valley is closed by choking smoke, Lake McDonald Lodge at Glacier National Park closes early for the second straight year due to wildfire, Whiskeytown National Recreation Area faces a long road to recovery. Rocky Mountain National Park is just a careless campfire away from a conflagration, lightning could spark another prairie fire that could race across Wind Cave National Park as one did last September, and numerous other units of the National Park System across the country are more vulnerable to fire than anyone can remember.

And in many cases those fires are bigger and hotter than they typically have been, Ferguson tells us.

"The closer we look, the clearer it's becoming that wildfire -- which has long exerted an enormous impact on Western lands -- is becoming a bigger force than ever before," he writes. "Between 2000 and 2015 an astonishing ten fire seasons saw more than a dozen so-called megafires -- a term still somewhat loosely defined but these days often applied to burns of more than 100,000 acres. There have been four years in the last half century when more than 9 million acres have burned in the United States, and all of them have been since 2006."

As Ferguson, a nature writer who calls Montana home, explains, blazes are becoming hotter and more destructive in part because of insects -- bark beetles -- that are becoming more damaging as the warming climate allows them to reproduce more quickly and reach stands of timber that in decades past were out of reach. The trees they kill turn into fuel along with trees that are stressed by the drought, which makes them more combustible. And the rapid pace of climate change now underway is speeding up those factors, he writes.

Climate change also is allowing more invasives, such as cheatgrass and loosestrife, to spread. And these are quick to dry out and quick to burn.

Oh, and because many folks love a home set in the mountains and surrounded by forest or next to national parks, the "wildland-urban interface" is growing.

"Of the 2.3 billion acres that make up the United States, about 1 billion, or 44 percent, of those acres are considered wildland-urban interface," Ferguson writes. "Of that, about 220 million acres -- an area roughly twice the size of California -- is now designated by state and federal land manager as being at high risk of wildlife."

Residents of northern California, in the Redding area, are well aware of that this summer.

Ferguson explains the dynamics of wildfire, looks at today's firefighters and how they battle blazes, discusses approaches to reducing disastrous wildfires, and even turns the pages of history back to explain why fires of the past weren't as deadly as those of today. Today's fires are bigger and more deadly because of the warmer climate, of course, but also because of the many years where fires were fought from the very beginning and so there were few "stand-maintenance fires" to cleanse the forest. The result was the buildup of an awful lot of fuel ready to be kindled.

"When early European explorers praised ponderosa pines, calling them regal, swooning over the sun-dappled parklike groves that were so easy to travel through on horseback and sometimes even by wagon, they were celebrating a forest thoroughly shaped by wildfire," he writes. "Not only fire in its more extreme form as scorching walls of flame marching across the mountains, but also the far more frequent low-to-moderate-intensity regular burns foresters today call stand-maintenance fires.

"When stand-maintenance fires occurred, burning through many western woodlands roughly every ten to fifteen years, what got burned up were the lower branches the trees had dropped and the occasional toppled tree, along with needles, cones, and small plants of the forest floor," explains Ferguson.

It's not unreasonable to view the recent Obi Fire that burned on the North Rim of Grand Canyon National Park as a stand-maintenance fire, as it creeped and crawled along, burning mostly through forest duff and dead and downed trees.

Land On Fire is a good read - with some incredible, full-color images of fires -- and a great educational tool to have if you live in the West or elsewhere in the country where wildfires are occasional visitors. For Westerners, the book describes a new fire regime that they'll need to learn how to live with ... or decide to live somewhere else.

"Those of us who elect to keep living in the craggy, enchanted landscapes of the American West, so rich with big sky and bright mountains and hushed forests, are now faced with making some measure of peace with this new world, to learn how to dance to a tune increasingly driven by big burns," Ferguson tells us. "Some of us, myself included, hope things will change, that one day the climate may settle back into patterns more similar to those that have been more or less reliably in play for centuries. But if we're honest, this hope we share is likely to bear fruit only long after we're gone. For now, and probably for a great many decades to come, we'll be living in the middle of a thoroughly arresting yet increasingly daunting landscape. A turbulent and often overwhelming land of fire."