More than half of the world’s population lives in cities and by 2100, this percentage is predicted to be much higher. This means that more homes will be built with steel and concrete, which both have very large carbon footprints. According to a study by the Potsdam Institute in Germany, housing a growing population in homes made of wood instead could avoid more than 100 billion tons of carbon dioxide emissions over the remainder of the century. This is about 10% of the remaining global carbon budget for staying below the 2-degree Celsius climate target.
The study presents the alternative of housing new urban populations in mid-rise buildings – no more than 4-12 stories high – that are substantially made of wood. Wood is a renewable resource that carries the lowest carbon footprint of any comparable building material. Trees take up CO2 from the atmosphere to grow. Producing engineered wood releases far less CO2 than production of concrete and steel and the finished product continues to store carbon.
The study shows that sufficient wood for new mid-rise urban buildings can be produced without a major impact on food production. The wood would come from timber plantations as well as natural forests. The study also looked at biodiversity impacts and ways that ecosystems could be protected while still providing the necessary timber.
Overall, the Potsdam study demonstrates that urban homes made out of wood could play a vital role in climate change mitigation based on their long-term carbon storage potential coupled with the reduced utilization of the carbon-intensive concrete and steel industries.
Photo, posted May 24, 2005, courtesy of Stig Anderson via Flickr.