While pounding nails on a roof extension for his shed this summer, Scott Rupp heard a roar that almost scared him off the roof. Three planes with bellies full of fire retardant swooped low, then banked over the mountain behind his home.

“I looked up and saw this big smoke cloud,” said the part-time farmer and leader of an organization devoted to studying climate change. “That was my first sense that this was something that was going to personally affect me.”

“This” was one of the largest wildfires in Alaska during the hot summer of 2013. It came close enough to Rupp’s homestead that he felt smoky heat on his face, a sensation that will now be on his mind every time he tweaks a computer model that simulates future fire scenarios in Alaska.

Rupp, 46, leads two lives in his home of interior Alaska. By day, he heads the Scenarios Network for Alaska & Arctic Planning, a group of about 20 scientists and staff who try to predict the future of Alaska climate so people can prepare. After work, he drives 30 miles to his 320-acre parcel off Chena Hot Springs Road. There, he hugs his wife and two daughters, along with a few dozen dogs, “too many” goats, chickens, and, soon, two 500-pound hogs.

He wants to make Flat Mountain Farm a place that sustains itself and other Alaskans. He’d prefer to spend most of his time there, but he needs money for goat feed. And he’s such a smart guy that others at the University of Alaska Fairbanks chose the former forestry professor to lead SNAP.

Part of his job is to decide which high-power computer models best simulate Alaska and predict what it will be like in 5, 10 and 100 years. A large component of those models is the occurrence of wildfires, a phenomenon that has fascinated him since his boyhood in Pennsylvania.

After working with local wildlands firefighters and managers in a dream project a few years ago that involved torching a black spruce forest on Nenana Ridge off the Parks Highway, Rupp had an idea of what Alaska wildfire could do to a landscape. In midsummer 2013, his education intensified.

It started with the retardant bombers buzzing his homestead. Rupp knew from his work on Nenana Ridge that the airships are expensive to operate and a person rarely sees them unless things are blowing up nearby. He thought the pilots were dropping their load of gooey red liquid just over the hill from his homestead.

The next day at work, he checked websites that showed the activity and growth of a fire that started on military land south of his home. If it had occurred in the Lower 48, the Stuart Creek fire would have eaten most of a county before stalling at a large river, poised to devour more.

As he drove home that night, he couldn’t help staring at the majestic cauliflower column that filled his windshield view. That day, winds fanned the fire to almost double its acres consumed. When Rupp motored down his long driveway, he pulled up to his home, greeted his family, and went to the end of a cleared field where he had a great view of the plumes erupting from a fire front about ten miles away and closing.

He admits he then became a man obsessed, a “geeky scientist that found the entire event fascinating and spending way too much time observing things . . . instead of worrying about prepping our property.”

His wife Kerry did not understand why Scott was standing in the grass taking photographs instead of herding the goats for a ride to the Tanana Valley State Fairgrounds, the evacuation point for animal owners along Chena Hot Springs Road.

With the fire rolling toward the Chena River and the paved road to the hot springs resort just beyond it, Rupp returned home the next day to find firefighters in his yard. They seemed pleased that Scott and Kerry had cleared well around their buildings and lived in an open hardwood forest.

The fire stalled for a few days, but on July 4 the firefighters were back on the Rupps’ property, setting up hoses and sprinklers on their roofs.

“That was a little bit unsettling,” Rupp said. “But I still had a hard time doing anything but going down to the end of the field and taking pictures. Those plumes were really impressive.”

By the end of his fire-watching session that day, he marveled at single trees exploding in flames across the river. From his Internet log-ins, he saw that a Type 1 fire crew was now in the area.

“It was pretty serious,” he said.

Before long, Rupp was alone with his goats and a half dozen dogs. Citing crazy winds and the fire’s advance, officials had called an evacuation notice. Kerry and the girls went to a friend’s house closer to Fairbanks.

Rupp had time to think about his decision not to leave, one he made after assuring himself that at most he would lose a barn or another outbuilding and that he, the goats and the dogs could find refuge in a half-acre garden patch if the fire came near. After working with the firefighters as part of his job, he suspected they could hold the line when the time came.

“These guys are the best in the world at what they do,” Rupp said. “I figured if anybody could have made a stand at the river, it was them.”

Soon, bathed in acrid orange smoke, he felt the radiative warmth of the fire on his cheeks. He could no longer see the mountain one-half mile behind his house and ghostly birch leaves fell from the sky, exploding to ash when they hit the ground. Rupp said he remained confident until the goats, as tame as household pets, began acting up.

“You could tell they were on edge, out of their normal sorts.”

He then wondered if he would be able to execute of his plan of luring the goats to the garden with a bowl of oats should he see the firefighters backing into his yard.

Luckily, he never found out if the freaked goats would follow him. The fire stalled at the river. More humid weather came in and wind, the “wild card” in the fire game, became calm. Rupp’s family returned home. Chena Hot Springs Road remained open the rest of the season. The autumn rains finally arrived. And Rupp might never look at his job the same way.

“A lot of scientists don’t even get to step on the landscape they’re modeling,” he said. “I found the whole experience to be enlightening and interesting.”

He also got a from-the-backyard view into what he predicts is Alaska’s future.

“In all cases with the models we use, we’re going to see more fire ahead than we have in the last 50 years,” he said. “Fire in the last 15 years has been on an uptick of activity, the population’s not decreasing here and a lot of fuels are available close to peoples’ homes. And if the weather hadn’t changed, my community (Pleasant Valley) was potentially going to be destroyed.”

Though the fire messed up his summer hay planting and other work on the farm, Rupp doesn’t seem to mind. And, he points out, when the boreal forest burns like that, it can’t go up in the same fashion for a long time.

“I’ve now got a great firebreak just below my house for the next 30 or 40 years.”

Since the late 1970s, the University of Alaska Fairbanks’ Geophysical Institute has provided this column free in cooperation with the UAF research community. Ned Rozell is a science writer for the Geophysical Institute.