of CO2 per year. Nevertheless, total demand for CCS would
remain well below the “Practical Storage Capacity” estimate
of potential geological CO2 repositories and would greatly
alleviate the challenges to mid- and long-term transitions to
limit climate forcing.
Like any other model comparison studies, the findings
from this research may be subject to limitations associated
with structural diversity among the participating IAMs.
Most importantly, they exhibit different reliance on various
mitigation responses—the upscaling of low-carbon technologies,
the premature retirement of emitting sources, and the
associated reduction in energy demand—which led to some
models suggesting relatively easy technology-based solutions
but others suggesting failure to achieve the long-term
climate goal after the delayed policy actions. While not
investigated in this study, our results would be sensitive to
the degree to which installed coal capacity can be prematurely
retired between 2030 and 2050 which varies among
the IAMs (see [39] in this issue). Further research is needed
to systematically explore the interaction between various
mitigation responses.