The fire burned down hillsides, charred trees, shrubs and houses, and burned 70,000 acres of land in northern California. But Sean Jennings’ house did not catch fire. Its red stucco walls and green roof look amazingly clean, perched on the hillside, among burnt cars and white ashes left by the fire. Inside, the Lego bricks and Christmas decorations have not melted, and the propane tank at the back of the house is ¾ full.
Jennings said his house survived the valley fire in 2015 because it was not built of wood. When he built it five years ago, Jennings switched to something called RSG 3-D panels-foam insulation blocks, fixed in a steel grid, fixed together, and covered with concrete. He said that this structure is stronger, less susceptible to termites, and less flammable than wood. “The wooden house is so fragile and leaky,” said Jennings, who is using RSG panels to build a second house for his mother in Sonoma County, which is close to the 2020 LNU Lightning Integrated Fire and destroyed 363,000 acres in six weeks. local.
As the western United States approaches the 2021 fire season and its conditions are drier than last year’s record fire, it makes sense to break up with wood, but the United States is still stubbornly attached to wood. It is one of the few places in the world. Wood is the main material used in the construction of new houses. According to data from the National Association of Housing Builders, 90% of the houses built in 2019 are made of wood. Although scientists emphasize the importance of trees in capturing carbon and mitigating climate change, the United States uses more forest products than any other country, not only for buildings, but also for furniture, flooring, and paper. Wood plays an important role in American folklore. He provided a residence for Abe Lincoln and hired Paul Bunyan.
Now, there are more and more economic reasons to find alternatives. After the building collapsed during the pandemic year, as more and more people across the country remodeled or built new houses, the cost of wood soared, resulting in a shortage of wood, and the cost of new single-family homes increased by more than $35,000.
“Timber is everywhere, but now is the time to evolve,” said Matt Watson, president of Gateway Builders, a northern California contracting company that has been building houses since 1997. Watson started using non-wood materials for construction last year and now, because he worked with clients who lost their homes in the 2020 fire, and 19 out of 21 reconstructions used non-wood materials. His workers exchanged hammers and nails for pneumatic tools that held the steel plates together. However, this may take a while, he said-old habits are hard to change. “It’s like keeping people away from fossil fuels.”
The world’s dependence on wood played a role in the fire that scorched the slopes of Jennings and destroyed 8.9 million acres of land in the western United States last year. Climate change has worsened drought conditions; keeping trees underground that absorb carbon dioxide and reduce human emissions is one of the most cost-effective ways to reduce carbon dioxide emissions. When Elon Musk tweeted in January that he would donate US$100 million to the Best Carbon Capture Technology Award, one user replied: “Congratulations to the people who invented the forest.”
However, according to a study published in the journal Nature in 2015, about 15 billion trees are cut down every year. Since the beginning of human civilization, the number of trees in the world has fallen by 46%. Although most of today’s logging activities occur in developing countries such as Brazil to make room for farmland, the United States harvests the world’s largest trees, cutting down millions of trees every year, and the harvesting cycle is shorter than ever.
“There was a time when they fell trees in a rotation every 60 or 80 years,” said Mike Roddy, a builder who has been advocating the downsides of timber for years since flying over the Pacific Northwest He has been a river guide since the ministry’s deforestation. “Then they think 40-year rotation is better,” Roddy said in his living room in Alameda, California, while flipping through a book showing the landscape of a large area of ​​deforested trees.
Private landowners account for the vast majority of trees felled in the United States. According to data from the National Federation of Forest Owners, about 7.8 million acres of forest (equivalent to the area of ​​Maryland) were cut down in 2019, and landowners replanted to keep the forest prosperous. But the shortened harvest cycle-as high as 120 years a few decades ago-has a major impact on the climate, because mature and old forests accumulate more carbon than young forests.
Beverly Law, a professor in the Department of Forest Ecosystems and Society, said: “Even if they are engaged in sustainable forestry, they maintain it below the maximum level that allows the forest to grow naturally.” At Oregon State University and the country One of the leading carbon researchers. (Only a small percentage of working forests in the world are certified as sustainable.)
Old trees are still being felled in an area that Law calls the “Gold Coast”, an area in the Pacific Northwest, where trees store more carbon per unit area than tropical forests. The Trump administration cancelled the protection of the Tongas National Forest in Alaska, one of the largest intact temperate rainforests in the world. This was one of his last actions before leaving office.
Steel may also be a driver of emissions, but 90% of the steel produced today is recycled, and it can be recycled indefinitely in ways that wood cannot. Most steel plants are now also electric arc furnaces, which are less energy-intensive.
Roddy has built more than 700 steel structure houses around the world, including those built for actor and environmentalist Ed Begley, Jr., and he said that concerns about carbon emissions were not the only reason that prompted him to reduce his dependence on wood. Due to the short harvest season, many of the felled trees are not strong enough to make the durable beams that were once used to build houses. Instead, builders designed wood or oriented strand board (OSB), which is made by gluing peeled wood products together. This material contains chemicals including formaldehyde, which has been shown to significantly deteriorate indoor air quality.
He said that houses built of steel and concrete will not be deformed by moisture or water damage, nor will they attract termites-this is why 72% of single-family homes built in Hawaii use steel frame structures, according to the Steel Structure Industry Association .
Forest owners argue that moving away from wood on a large scale actually harms the environment; if there is no market for trees, they say that landowners have little incentive to plant trees, but may turn their land into farmland or houses. According to the National Federation of Forest Owners, about 1 billion trees are planted in the United States every year. In addition, NAFO spokesperson Kate Gatto said that wood still stores carbon when used in houses. (There is controversy about how much carbon the trees actually store after being felled for use in households; Law estimates that only about 20% of the wood harvested in the last century is still used for long-term products, and the rest has already entered the atmosphere.)
The forest products industry argues that staying away from wood will result in fewer jobs in sawmills and manufacturing; they estimate that forestry-related companies support more than 1 million jobs. In addition, about 7 million of the 123 million private-sector workers in the United States are in the construction industry, although Roddy said that it is not difficult for people who are used to building with wood to switch to other products.
Although proponents of steel structure houses say that energy saving can save money in the long run, it is not clear how much it will increase initial construction costs. Roddy estimates that building a house with steel should increase the cost by about 3%. Larry Williams, executive director of the Steel Structure Industry Association, said that to build a 2,120-square-foot house will cost approximately US$28,000 in wood and US$10,000 in steel, while the labor force for steel-structured houses will cost an additional US$1 per square foot. However, Bone Structure, a Canadian company that manufactures prefabricated steel houses, said that the construction cost of its houses is about 10% higher than that of wooden houses.
The United States has the world’s highest housing insurance rates and the highest rate of housing fires. Even in fire-prone areas, housing insurance companies will not discount buildings constructed of steel or concrete. In fact, they usually require homeowners to rebuild quickly after a fire to qualify for compensation, so it may be tempting to build a house with wood because this is what builders have been doing, and there are ready supplies of materials and workers. Many timber companies even offer discounts to customers whose houses have been burned to unload supplies.
This is a cycle that worries Roddy’s business partner, forest ecologist, and Chief Scientist of Wild Heritage, Dominick DellaSala, watching the reconstruction of talent in his hometown of Oregon, which was devastated by fire in September 2020. “This is the definition of madness, right?” DellaSala said as he saw “stick” houses made of wood. “Do the same thing and expect different results.”
He said piles of old trees salvaged from the burned forest are located in the lumber yard around the town. Temperatures in parts of Oregon were extremely high in May, and over 97% of Oregon was exceptionally dry.
A few years ago, Sara Woodfield, an architect in Sonoma County, California, tried to use RSG panels to help a group of homeowners who lost their homes in the 2017 Tubbs Fire, just like those who protected the Sean Jennings home. However, because the contractor told them they could only build with wood, they began to give up their promises to use combustible materials one by one.
Woodfield said that after last year’s record fire season, she saw a growing interest in non-flammable materials, but most architects are still building with wood. “We are too used to wood-it is free and available, but now we have used it up, we have to find another way,” she said.
The scientists agreed, saying that now is a critical moment for the earth. The latest report of the Intergovernmental Panel on Climate Change stated that if the world does not reduce greenhouse gas emissions, the atmosphere will heat up by as much as 2.7 degrees Fahrenheit by 2040.
At the same time, the high demand for wood may result in more trees being felled, not fewer. Due to rising timber prices, poachers have cut down at least 100 old trees on Vancouver Island, Canada this year. As fires ravage more areas in the west, wood recyclers are using loose post-wildfire rules to remove old trees from burned forests.
With the fire season approaching again this year, timber companies are trying to convince western states that they need to increase logging to prevent forest fires. Science proves that the opposite is true-the thinning of the forest will leave “slash fragments”, thereby increasing the intensity of the fire.
“People want to cut down the forest to stop the fires-it won’t work,” said De La Salla, whose research shows that logging is the largest producer of carbon dioxide in Oregon.
Ultimately, the economic factors that pushed Sean Jennings to push others in this direction may be the same. When Jennings was planning his new house, he learned that the insurance company would not cover it because its location was prone to fire. This convinced him to look for non-flammable materials to protect his investment.
According to data from the American Association of Home Builders, the number of concrete-framed houses built from 2018 to 2019 increased by 46% due to changes in the building codes of the Southern U.S. hurricane. The market share of concrete frame houses is now twice that in 2009, when they accounted for only 5% of the market. Watson, a builder in Northern California, has already approached some wineries that have cancelled fire insurance and are looking for alternative wood.
But widespread adoption still has a long way to go. Kevin Stout, who lives near Talent, saw the impact of the Almeida fire last year and wanted to build a new home with steel or aluminum frames. The fire destroyed 3,000 buildings. The contractor said that he needed specialized labor to build things other than wood, and because of the high demand for new houses after the fire, it was already difficult to find a contractor. He is worried that if he builds with unusual materials, he may not be able to obtain a housing loan; in addition, he likes the idea of ​​building houses with wood to sequester carbon.
Then, a friend sent Stott a photo of her father’s house in Santa Rosa, California. The house was built of concrete but was destroyed by a fire in 2020. Stout began to wonder whether the steel structure house would be surrounded by wooden houses he saw neighbors build. “Perhaps it would make sense if every house was built with less flammable materials,” Stott said. Now he plans to rebuild with wood. “In a catastrophic fire, I am sure that my house will be burned down,” he said. “I will only build one more.”