Does Decreased Forest Harvest Cause Substitution of Higher Global Warming Products? An Empirical Study.

Forests play an important role in climate change mitigation, but the question of how to manage forests for the greatest climate mitigation benefit remains uncertain. On one hand, standing forests remove CO2 from the atmosphere. On the other hand, harvested forests provide a source of wood products, which generally have lower emissions associated with their production than concrete, metal or plastic alternatives. However, it is not well understood to what extent forest conservation will lead to substitution.

We analyzed changes in softwood lumber production, import, export, manufacturing, and substitution in the USA from 1988 to 1998; a period characterized by decreased forest harvests from public lands in the USA along with increased lumber prices and demand. To complete this study, we developed an analytical framework based on supply and demand but tracking volume of softwood lumber and its equivalents. We empirically quantified changes in eleven different aspects of the market in response to decreased harvest and increased demand. The results showed substitution of wood products by metal, concrete and plastic was less than 10%.

This research demonstrates the need for forest-based climate change mitigation strategies based on integrated global models that incorporate realistic estimates of substitution between wood products and alternatives, as well as other responses to shifts in wood products supply and/or demand. Given the uncertainty about potential substitution benefits of forest harvesting, we encourage people developing forest carbon strategies to implement a portfolio of options. We hope our study will stimulate further research in this area.