Thermochemical biomass conversion: Impact on the biosphere

Low land use and tiny emissions, as long as residues are used

What this tab covers Effects on human, animal, plant, fungal and microbial life and on whole ecosystems: in the short term (construction and early years), medium term (operating life) and long term (decommissioning and legacy).

Few studies quantify the biosphere impacts of thermochemical conversion as such; most impacts come from where the biomass is sourced, which these routes can largely confine to wastes and residues.

Life-cycle emissions, Fischer-Tropsch jet from residues (ICAO) 7.7-8.3 g CO2eq/MJ⁷ EU typical saving, waste-wood Fischer-Tropsch diesel 83%⁶ EU typical saving, waste-wood DME 84%⁶

Effects over time

Life affected	Short term	Medium term	Long term
Humans⁴	Little evidence of effect in the sources reviewed; syngas contains carbon monoxide, a workplace hazard.	Little evidence of effect in the sources reviewed.	Little evidence of effect in the sources reviewed.
Animals¹⁰	Little evidence of effect in the sources reviewed.	Little evidence of effect in the sources reviewed.	Little evidence of effect in the sources reviewed.
Plants¹⁰	Little evidence of effect where residues are used.	Purpose-grown biomass would need about 58,000 ha per TWh a year, against about 130 for residues.	Little evidence of effect in the sources reviewed.
Fungi and soil life³	Little evidence of effect in the sources reviewed.	Biochar from slow pyrolysis can be added to soil, but its effects were not quantified in the sources reviewed.	Little evidence of effect in the sources reviewed.
Ecosystems⁷	Little evidence of effect in the sources reviewed.	Residue-based Fischer-Tropsch fuels cut life-cycle emissions by about 91% against fossil jet (calculated from 7.7-8.3 versus 89 g CO2eq/MJ).	Little evidence of effect in the sources reviewed.

How the effects are reduced

Using forestry and agricultural residues and municipal waste keeps land use low (about 130 ha per TWh a year) and gives the lowest default emissions values. Tar and gas cleaning systems control air pollution from gasifiers. Burning pyrolysis char and gas inside the process avoids external fuel. Where biochar is returned to soil, it can store carbon, though this was not quantified in the sources reviewed.

Sources

Fast pyrolysis: key points (table of product yields by pyrolysis mode) IEA Bioenergy Task 34 (Direct Thermochemical Liquefaction)
Energy Technology Essentials ETE03: Biomass for Power Generation and CHP (2007 cost estimates) International Energy Agency (copy hosted by nachhaltigwirtschaften.at), 2007
Directive (EU) 2018/2001 (Renewable Energy Directive II), Annex V Part B: estimated typical and default savings for future biofuels. Default values not changed by amending Directive (EU) 2023/2413 (RED III); a Commission revision was in draft in 2026 European Union (EUR-Lex), 2018
CORSIA Default Life Cycle Emissions Values for CORSIA Eligible Fuels (ICAO document 06) International Civil Aviation Organization, 2025
Land-use intensity of electricity production and tomorrow's energy landscape (Lovering, Swain, Blomqvist and Hernandez) PLOS ONE, 2022