The Fern Lake Fire's destruction reached as far as Moraine Park, a grassy valley carved by glaciers that's a feeding ground for elk, a couple miles from the fire's origin and close enough to the nearby town of Estes Park that hundreds of people had to be evacuated from their homes. Now, blackened stalks stick up from patches of snow. In some spots the charred ground lies exposed to the sky. The fire torched the trunks of a grove of aspen trees already damaged by elk antlers (the elk have run rampant in the park since the decline of predators like wolves). The upper branches are unscathed, but it's unclear if the trees will survive.

A trail at the end of the valley follows a swift mountain stream up to Fern Lake. It also passes the southern end of the canyon where the fire began, and is the likely route of the campers who started the blaze. On New Years Eve, the air was frigid and there were several inches of snow on the ground, but the smoke still lingered, making it more difficult to breathe in the thin air at more than 8,000 feet above sea level. After two miles, it was possible to see the bald patches on the mountains that mark the route the fire took. The fire began near the dense, wooded floor of Forest Canyon and blew to the top of the ridge. Then it went south, across the river and along another ridge to Moraine Park. Along its path, blackened, skeletal remains of pine trees stood silhouetted against the white snow.

At first glance, it was hard to tell which trees were burnt and which were already dead from the beetles, which burrow into a tree and kill it from the inside out. A few trees were still sending plumes of white smoke into the air. A crew of four firefighters on staff with the national park had been dispatched to check on remaining hot spots. After hiking in to take a look, they said they weren't worried the fire would restart -- as long as it snows again soon.

Maybe it will snow heavily this winter, and it's possible the fire was just a freak event. "Cause and effect with global climate is hard. ... Change is a part of nature," said Ben Bobowski, the chief of resource stewardship for Rocky Mountain. But, he added, "This has never happened in our history."

It's the growing list of never-before-seen events like the Fern Lake Fire that's worrisome, and that has contributed to the consensus that humans, not nature, are behind the catastrophes. In New Mexico, a huge burn that destroyed more than 350 square miles of forests last summer was the largest in the state's history. In Australia, tens of thousands of acres are now burning in the wake of record-breaking temperatures. Beetles have consumed Western forests on an unprecedented scale. And a study co-authored by Craig Allen in 2010 found recent examples "of extensive forest die‐off in all major forest types worldwide, from tropical rainforests in the Amazon to African savannas and Mediterranean pine forests to boreal forests in Canada and Alaska," all because of drought and heat potentially connected to the changing climate.