Global spatially explicit CO2 emission metrics for forest bioenergy

Area of Science:

• Climate Science
• Environmental Science
• Forestry

Background:

• Emission metrics standardize greenhouse gas climate impacts (e.g., global warming potential).
• Forest bioenergy is crucial for energy, yet CO2 emission metrics are often case-specific.
• Existing metrics lack global, spatially explicit data for forest bioenergy.

Purpose of the Study:

• Develop global, spatially explicit emission metrics for CO2 from forest bioenergy.
• Apply these metrics to assess 2015 emissions and project impacts until 2100 under the RCP8.5 scenario.
• Investigate factors influencing these emission metrics.

Main Methods:

• Calculated global average values for GWP, GTP, and aSET for forest bioenergy CO2.
• Modeled emission metrics considering temperature, precipitation, biomass turnover, and residue extraction rates.
• Applied metrics to global emissions data for 2015 and RCP8.5 projections to 2100.

Main Results:

• Obtained global average GWP: 0.49 ± 0.03 kgCO2-eq. kgCO2⁻¹.
• Obtained global average GTP: 0.05 ± 0.05 kgCO2-eq. kgCO2⁻¹.
• Obtained global average aSET: 2.14 × 10⁻¹⁴ ± 0.11 × 10⁻¹⁴ °C (kg yr⁻¹)⁻¹.
• Identified higher emission metrics under low precipitation, long rotation times, and low residue extraction rates.

Conclusions:

• The study provides the first global, spatially explicit emission metrics for forest bioenergy CO2.
• These metrics are crucial for accurate climate impact assessments of bioenergy.
• Findings support informed decision-making for sustainable forest bioenergy use across scales.