Biogenic Carbon Storage in the Technosphere

Considerable amounts of biogenic carbon (bio-C) are stored
in the
global technosphere, yet the magnitude, distribution, and longevity
of this storage remain poorly understood. This study quantifies annual
bio-C flows into durable goods (gross additions to stock, GAS) and
landfills across the global economy using Multi-Regional Supply-Use
Tables and detailed extension accounts for 2011. We develop a novel
material flow analysis framework that distinguishes feedstock uses
from GAS, and apply lifetime-based discharge modeling until 2100 to
track end-of-life bio-C fate across recycling, landfill, and emission
pathways. In 2011, 0.96 ± 0.15 gigatons of bio-C (GtC/year) was
stored in GAS and landfills. However, product lifespans constrain
long-term storage potential as 46% of stored carbon is going to be
discharged before 2050. Sensitivity analyses on product lifetime assumptions,
lifetime distribution functions, and the methane generation factor
in landfills reveal substantial variability in both the retention
of bio-C and the timing and magnitude of associated emissions. Furthermore,
improved landfill management could reduce cumulative methane-related
global warming impacts by up to 16%. Our findings highlight the temporal
dynamics of bio-C storage in the technosphere and underscore the importance
of extending product lifetimes, increasing recycling rates, and improving
landfill management to support climate change mitigation strategies.