Commercial forests could produce long-term climate benefit

June 22 (UPI) -- Planting new commercial forests in areas with temperate, wet climates could offset climate change by reducing greenhouse gas emissions created during harvesting, a study published Tuesday by Nature Communications found.

By planting in regions where forest growth rates are high, new commercial conifer forests could deliver nearly 270% more climate mitigation than semi-natural broad-leaf forests by 2120, the researchers said.

Future deployment of carbon capture and storage technology can also be used to transform wood bio-energy into a "negative emission technology" capable of removing carbon monoxide, or CO2, from the atmosphere long-term.

These commercial forests would effectively become natural "carbon sinks," -- areas that collect and store environmentally hazardous CO2 -- according to the researchers.

"New commercial forestry doesn't necessarily have to be harvested in the future," study-co-author John Healey said in a press release.

The decision would depend on the future "value of keeping carbon 'in the ground' versus storing it in various wood products and ... using it for bio-energy, preferably with carbon capture" to keep it out of the atmosphere, said Healey, a professor of forest sciences at Bangor University in Wales.

For this study, Healey and his colleagues applied a new, time-dependent assessment to capture the complex dynamics of carbon uptake, storage and partial eventual release back to the atmosphere, alongside product and energy substitution by wood products, over a 100-year timeframe.

The assessment considered multiple wood uses, such as construction timber, paper and bio-energy and included future projections on wider decarbonization of substituted products and energy.

"Our goal was to undertake a really comprehensive life cycle assessment that considers the whole life cycle of carbon taken up by trees in new commercial forests," study co-author Eilidh Forster said in a press release

"Because new forests won't be harvested for another 50 years, the standard assessment approach of applying current technology emission factors to wood value chains is inaccurate," said Forster, a doctoral student at Bangor University.

Future deployment of carbon capture and storage technology effectively transforms wood bio-energy into a "negative emission technology" capable of removing CO2 from the atmosphere long-term, the assessment showed.

Carbon capture and storage technology is designed to extract CO2 from exhaust gases during energy generation and stores it in old oil and gas wells.

Assuming widespread use of carbon capture and storage after 2070 means that new commercial forestry can be a long-term CO2 sink, even if a large share of wood is ultimately burned for bio-energy generation, the researchers said.

However, a large share of carbon removed from forests during harvesting is locked up for many decades in wood products, such as wood and panel boards used for construction, they said.

Not only does this delay the release of carbon back to the atmosphere, but it "buys time" for successful commercial deployment of carbon capture technology in the future.

For example, a significant share of wood produced in a forest planted today may not be combusted for another 100 years or more if it is used in a hierarchical value chain that prioritizes higher-value use in construction or advanced bio-based materials, they said.

Afforestation can "offset current greenhouse gas emissions [and] at the same time can provide a crucial feed-stock for the circular bio-economy that we expect to be expanding rapidly," said study co-author Caren Dymond, a research scientist with the province of British Columbia in Canada.

The findings contradict those of recent studies that suggest commercial forests act only as a short-term reducer of CO2, according to the researchers.

These new results indicate that, where forest growth rates are high, such as in temperate wet climates, new commercial conifer forests could deliver up to 269% more climate mitigation than semi-natural broad-leaf forests by 2120, they said.