Carbon Dioxide Removal methods
and their role in mitigation strategies
O l i v e r G e d e n ( W G I I I c h 1 2 & C W T S Y R )
I P C C S i d e E v e n t C O P 2 7 ,
S c i e n c e f o r C l i m a t e A c t i o n P a v i l l o n
S h a r m E l - S h e i k h , 1 7 N o v e m b e r 2 0 2 2

Definition of Carbon Dioxide Removal
Anthropogenic activities removing carbon
dioxide (CO2) from the atmosphere and durably
storing it in geological, terrestrial, or ocean
reservoirs, or in products.
It includes existing and potential anthropogenic enhancement
of biological or geochemical CO2 sinks and direct air carbon
dioxide capture and storage (DACCS), but excludes natural
CO2 uptake not directly caused by human activities.
G L O S S A R Y „ C A R B O N D I O X I D E R E M O V A L ( C D R ) “

IPCC AR6 WG III, SPM, C.11
CDR in Summary for Policymakers
C.11 The deployment of Carbon Dioxide Removal
(CDR) to counterbalance hard-to-abate residual
emissions is unavoidable if net zero CO2 or GHG
emissions are to be achieved. The scale and timing
of deployment will depend on the trajectories of
gross emission reductions in different sectors.
Upscaling the deployment of CDR depends on
developing effective approaches to address
feasibility and sustainability constraints especially
at large scales. (high confidence)
{3.4, 7.4, 12.3, Cross-Chapter Box 8 in Chapter 12}

• Global and national
mitigation pathways
share basic components
• 3 complementary roles
of CDR in ambitious
mitigation parthways
• We‘re already doing
CDR (via LULUCF), but
scale-up mainly by novel
methods with longer
storage timescales
• Net-zero GHG reached
later than net-zero CO2
emissions
C H A P T E R 1 2 , C R O S S - C H A P T E R B O X 8 , F I G U R E 2

Summary for Policymakers, Figure SPM.5 & Chapter 12, Figure 12.3

• Taxonomy based on
WG I, highlighting
removal process &
timescale of storage
• Often several
implementation options
per CDR method
• Vulnerability to
reversal as major
concern for carbon
stored in vegetation,
soils and sediments
• CCS & CCU can be
components of CDR
methods, with durable
storage of CO2 from
biomass or ambient air
C H A P T E R 1 2 , C R O S S - C H A P T E R B O X 8 , F I G U R E 1

Chapter 12, Table 12.6

Research needs &
knowledge gaps
S U M M A R Y F O R P O L I C Y M A K E R S & C H A P T E R 1 2
Fundamentals
• Definition of durability
• Monitoring, reporting and
verification of carbon flows
Characteristics of Methods
& Pathways
• Effectiveness of methods
(costs & potentials)
• Risks & co-benefits of deployment
• Residual emissions vs. CDR
Governance & Policy
• Feasibility & sustainability
constraints, risks & co-benefits
• Certification & accounting
• Targeted incentives

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THANK YOU
DR OLIVER GEDEN
G e r m a n I n s t i t u t e f o r I n t e r n a t i o n al a n d S e c u r i t y A f f a i r s ( S W P )
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