Presentation given by Dr Tim Kruger from the University of Oxford on "Greenhouse Gas Removal: Proposed Techniques" at the UKCCSRC Direct Air Capture/Negative Emissions Workshop held in London on 18 March 2014

1. Greenhouse Gas Removal: Proposed
Techniques to Remove Greenhouse
Gases from Ambient Air
Tim Kruger
Oxford Geoengineering Programme
Oxford Martin School
University of Oxford
18 March 2014

2. Climate Change

3. Ocean Acidification

4. What is geoengineering?
• The deliberate large-scale intervention in the
Earth’s natural systems to address climate
change

5. Some proposed
geoengineering techniques

6. Prevention is better than a cure…
• “The safest and most predictable method of
moderating climate change is to take early
and effective action to reduce emissions of
greenhouse gases” (“Geoengineeringthe
Climate: Science, Governance and
Uncertainty” Royal Society, 2009)

7. … but if we can’t prevent it,
we sure need a cure
Source: “How difficultis it to recover from dangerouslevels of globalwarming?” J A Lowe, C Huntingford, S R B
Raper, C D Jones, S K Liddicoat and L K Gohar Environ. Res. Lett. 4 (2009) 014012

8. The scale of the challenge

9. Do we have a reverse gear?
“Global greenhouse gas emissions need to peak this
decade, and get to zero net emissions by the second half
of this century” Christiana Figueres (Executive Secretary
of UNFCCC, 8 November 2013))
But as is made clear in the UNEP Emissions Gap Report
(2012) “To achieve such negative emissions is simple in
analytical models but in real life implies a need to apply
new and often unproven technologies or technology
combinations at significant scale”

10. Proposed GGR techniques

11. Implications of GGR for CCS
• Some (but not all) GGR techniques
assume geological storage capacity 
potentially massively increased demand
for storage sites
• GGR storage sites do not need to be
proximately located to emissions from
point sources

12. Alternative storage processes
• In situ carbonation of peridotite
• Carbon stored in biomass
• Carbon stored in biochar
• Liquid CO2 stored on the ocean seabed
• Dissolved Inorganic Carbon stored in the
oceans

13. Carbon-negative power
NaturalGas Air Limestone
Pure CO2 Electricity Lime
Geologicallysequestered Limestone
AbsorbsCO2 from
ambientair

14. Atmosphere Restoration Centre

15. Thank You