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Mass Timber
Reforestation as an antidote to global warming?

Mass Timber, a research project based in the USA, is developing scenarios on how a greater use of wood products would affect forests and the climate. The aim is to increase positive effects and minimise undesirable risks.

ResearchLifecycle assessments and lifecycle costs

Gigantic reforestation programmes could potentially mitigate climate change. To ensure that hundreds of millions of hectares really are planted with trees in the next decade, the demand for wood products should be increased. The opportunities are particularly high in the construction industry, as 11% of greenhouse gas emissions are currently caused by the use of steel and concrete. And consumption is predicted to double over the next 40 years. Solid wood, including cross-laminated timber and laminated timber, also appears to be an attractive alternative for multi-storey buildings.

But what global impact would an increased demand for timber products have?

The interrelationships are complex. The carbon stored in the forest could increase or decrease, for example due to faster-growing wood species that are harvested in shorter periods of time. Harvesting, transport and production can cause more or fewer emissions, carbon can be stored for longer (in buildings) or shorter (in chopsticks). And in the end, wood products can be reused or recycled.

The Mass Timber project

In order to assess the overall impact, an international research project led by The Nature Conservancy Arlington, USA, is gathering the necessary information from key regions. In phase 1, comparative life cycle assessments are being drawn up, 5 in the USA, 1 each in Chile, Europe and China. For the European reference building calculated by the IBO, it was shown that over a hundred-year service life, the energy supply during operation is decisive, while the carbonisation of CO2 is completely negligible. In principle, the solid timber building has a lower GWP in all life cycle phases than the reference building made of reinforced concrete.

Dynamic LCA

The current calculation methods for life cycle analyses represent the greenhouse gas emissions selectively in the respective phase without showing the actual effects, which are strongly dependent on the dwell time. However, dynamic LCAs, developed at the École Polytechnique Montreal in Canada, are also calculated at the IBO because they can provide a much more meaningful picture. This enables decision-makers - before international standardisation introduces such methods - to recognise and take into account the effects on the climate today.

Project team

Lead: The Nature Conservancy Arlington, Virginia, USA

Partner: diverse Universitäten in USA, Chile, China und Südkorea

atelierjones (Architekt) Seattle, Washington, USA

CORRIM – Corvalis, Oregon, USA

IBO für Phase 1

Research period

January 2020 – September 2020

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