There’s not enough land to solve climate change with wood buildings and biofuels

The report highlights a misconception at the heart of how policymakers think about plants.

A single corn plant, converted into ethanol fuel, may be carbon neutral if the CO2 emissions produced when it’s burned in a car engine are equal to what the plant consumed while growing. But if using that corn for ethanol means cutting down a forest somewhere else in the world to make space for food crops, the net climate effect is likely negative. Too often in climate policy, land is treated like an inexhaustible resource or afterthought, when in fact the conversion of land to produce ostensibly low-carbon commodities can be just as damaging as the use of fossil fuels.

The report takes particular issue with the emerging trend of using wood to replace carbon-intensive steel and concrete in construction. New processing techniques have made it possible to build much larger and more durable structures from wood, which could have a lower carbon footprint and be easier to recycle. Wood-based large construction projects are booming in the U.S., according to Bloomberg.

There are a few problems with this approach, Waite argues. Much of the mass of a tree is wasted during harvesting and production, which creates emissions as it decomposes. There is also a carbon opportunity cost in harvesting trees, which would continue to absorb CO2 if not harvested. Most important is the land limitation: All existing timber production lots already have customers lined up. There isn’t extra wood sitting around for construction projects to use, so a boom in wood building would have to eat into the global land budget, displacing agriculture or some other land use and leading eventually to the cutting of old-growth forests, a practice that world leaders have promised to end by 2030. The upshot is that policymakers should proceed with caution before introducing new incentives for wood construction, as they have recently in Germany, for example.

“We shouldn’t increase demand for new land-based products until we can demonstrate that demand for other land uses has peaked,” Waite said.

Wood-based construction isn’t necessarily a lost cause. If other uses of wood, especially single-use paper products, can be cut back, and some of that existing wood supply redirected to offsetting the use of steel and concrete in construction, it could shave about 25% off the net annual carbon footprint of wood production, WRI finds. Relying exclusively on wood from fast-growing forests, and reducing waste, would also make wood more attractive as a construction material, especially if the steel and concrete industries fail to make much progress on weaning off their heavy use of coal.

European policymakers are debating whether wood should qualify as a renewable energy source, when burned for heat or power. The war in Ukraine has boosted calls for alternatives to Russian gas, including wood, and demand for wood pellets is rising quickly in the European Union. That demand is driving deforestation on the continent, particularly in Romania, where environmental groups have found evidence of increased logging in protected areas.