Exploring site-specific carbon dioxide removal options with storage or
sequestration in the marine environment - The 10 Mt CO2 yr-1 removal
challenge for Germany
Abstract
Marine carbon dioxide removal (mCDR) and geological carbon storage in
the marine environment (mCS) promise to contribute to the mitigation of
global climate change in combination with drastic emission reductions.
However, the implementable potential of mCDR and mCS depends, apart from
technology readiness, also on site-specific conditions.
In this paper, we explore different options for mCDR and mCS, using the
German context as a case study. We challenge each option to remove 10 Mt
CO2 yr-1, which accounts for 8-22% of projected hard-to-abate
and residual emissions of Germany in 2045. We focus on the
environmental, resource, and infrastructure requirements of individual
mCDR and mCS options at a specific site, within the German jurisdiction
when possible. Furthermore, we discuss main uncertainty factors and
research needs, and, where possible, cost estimates, expected
environmental effects, and monitoring approaches.
In total, we describe ten mCDR and mCS options; four aim at enhancing
the chemical carbon uptake of the ocean through alkalinity enhancement,
four aim at enhancing blue carbon ecosystems’ sink capacity, and two
employ geological off-shore storage. Our results indicate that five out
of ten options would potentially be implementable within German
jurisdiction, and three of them could potentially rise to the challenge.
This exercise provides a basis for further studies to assess the
socio-economic, ethical, political, and legal aspects for such
implementations.