While it is unlikely that timber can fully replace any of these materials, new types of engineered wood are making it more competitive. One of these is cross-laminated timber (CLT), which is made by gluing together layers of wood to create panels that are as strong as steel or concrete, and thus can replace those materials in buildings.
More research is required to determine the precise benefits of using timber to cut CO2 emissions. One estimate comes from architect Anthony Thistleton-Smith, one of the United Kingdom’s leading experts on wooden buildings. He recently noted that, whereas a typical British home has a carbon footprint of around 20-21 tons, a CLT home has a negative footprint of 19-20 tons. In other words, every home built with CLT saves 40 tons of CO2 emissions. If the 300,000 new homes targeted for completion in the UK this year were built using CLT, it would be like taking 2.5 million cars off the road. The climate benefits could be massive.
As with so many climate measures, cost can be a major barrier to implementation. And, according to a United Nations report, CLT is more expensive than concrete in Europe. But CLT is still in its infancy, with only a handful of factories in operation. As the CLT supply chain develops, costs will inevitably fall, as has happened with renewable energy.
Moreover, builders report that the total costs of building with CLT already end up similar to those of building with concrete, because it takes less time. After all, unlike concrete, CLT doesn’t need time to set.
Of course, delivering such a transformation will not be easy. Vested interests—pressure from industries producing traditional building materials—must be overcome, including by ensuring a level playing field in terms of subsidies. Furthermore, public concerns—for example, regarding fire safety or infestation prevention—must be addressed, and builders will have to learn new skills. Most important, monitoring will have to be improved considerably, so that increased demand does not result in more deforestation.
For many countries, the economic opportunities should be sufficient to make addressing these challenges worthwhile. New plantations could regenerate rural areas, as new factories created opportunities for investors and entrepreneurs. Governments and larger companies would be able to tap the fast-growing green-bond market to fund the early transition, including the creation of systems using drones and satellite imaging to monitor for unsustainable forestry practices.
Opportunities to align economic development with the reduction of greenhouse-gas emissions are rare. Yet that is what reforestation offers. We must take advantage of this opportunity, by pursuing a construction transformation based on restoring trees, the world’s most effective carbon-capture tool. In this “new age of timber,” we would grow wood, build with wood, and allow our forests to thrive.