This presentation was presented during the Plenary 3, Working group, Conclusion and Closure of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Mr. Pete Smith from FAO, in FAO Hq, Rome

1. Unlocking the potential of SOC for climate
action, food security and sustainable
development - a feasible future
Pete Smith
Professor of Soils & Global Change, FRSB, FRSE,
Institute of Biological & Environmental Sciences
University of Aberdeen,
Scotland, UK.
E-mail: pete.smith@abdn.ac.uk

2. SOC for climate action

3. https://ccafs.cgiar.org/http://www.fao.org/home/en/
Climate Smart Agriculture

4. What does CSA aim to do?
• Climate-smart agriculture promotes production
systems that:
– Sustainably increase productivity,
– Increase resilience (adaptation),
– Reduce/remove GHGs (mitigation), and
– Enhance achievement of national food security and
development goals.
https://ccafs.cgiar.org/http://www.fao.org/home/en/
www.fao.org/climatechange/climatesmart/en

5. So where do soils fit it?

8. Decision tree for
enhancing C in
croplands
Paustian et al. Nature (2016)

9. Global potential for agricultural GHG mitigation
Paustian et al. Nature (2016)

11. Soil C & biochar mitigation potentials
• Biochar (Woolf et al., 2010)
– Technical potential = 1.8 Gt Ceq/yr
– Potential accounting for competition for non-waste
biomass = 0.7 Gt Ceq/yr
• Soil C sequestration (Smith et al., 2008; Smith,
2012)
– Technical potential = 1.3 Gt Ceq/yr
– Economic potential at 20-100 US$/tCO2eq = 0.4-0.7
Gt Ceq/yr
Smith GCB (2016)

12. Impact / limit summary for NETS
(with biochar and SCS)
Smith GCB (2016)

14. SOC for food security

16. Relative annual change in SOC (0-20 cm) (%)
0 2 4 6 8 10 12 14
Relativeannualchangeincropproductivity(%)
0
10
20
30
40
50
s
s
W
C
W
CMM
M
M
M
M
M
M
M
M
M
B
M
B
M
B
M
B
M
B
M
B
M
M
M
M
M
M
M
M
M
C
M
C
M
C
M
M M
M
M
S
W
M
M
WW
W
W
R
RR
R
W
W
W
W
R
R
R
S
W
SW
S
W
S
W
S
W R
R
R
R
R
R
R
RW RR
WW RR
WWRR
W
W
R
R
R
R
PP
PPP
PPP
W R
R
R
RRW
W
W
WW
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
RM
MM
M
C
C
C
C
Meta-analysis of 32 papers, reporting 151 relevant comparisons of location, practice, and crops over 4 years or more.
Crop species: B, beans; C, cassava; M, maize; P, sweet potatoes; R, rice; S, soybean; s, sorghum; W, wheat. Field
experiment regions: Africa (Black); Asia (Green); Latin America (Blue). The solid line is the Standard Major Axis regression
for all data points (n=151, Spearman’s rank correlation: y= 0.495 + 3.21 x; r=0.205, P<0.012).
Increasing SOC increases crop productivity
Frank et al. (in revision)

17. Does SOC increase yield or does yield increase SOC?
Hijbeek et al. (2016)

18. SOC increases yield and yield stability
Pan et al. (2009)
in most eco-climate zones, where the climatic drivers of yield are similar, the provinces with
higher SOM also tend to have a statistically higher yield. Causality cannot be firmly attributed
as a high yield is associated with higher plant production, potentially higher carbon inputs to
the soil and therefore higher levels of SOM over time. Nevertheless, within regions with
similar current climatic growing conditions, which should give similar yields if climate is the
over-riding factor determining current yield, those provinces with higher SOM tend to have
higher yield.

19. Threats to soils…. SOC to reverse
degradation
Smith et al. GCB (2016)

20. Threats to soils….SOC to reverse
degradation
Smith et al. SOIL (2015)

21. Threats to soils….
SOC to reverse
degradation
FAO & ITPS (2015)
“The overwhelming conclusion of the first-ever
comprehensive report on the world’s soil
resources, prepared by the Intergovernmental
Technical Panel on Soils (ITPS), is that the
majority of the world’s soil resources are in
only fair, poor or very poor condition... and
that conditions are getting worse in far more
cases than they are improving. Further loss of
productive soils will severely damage food
production and food security, amplify food
price volatility, and potentially plunge millions
of people into hunger and poverty.

22. SOC to help deliver the UN SDGs

23. The significance
of soils and soil
science towards
realization of the
UN sustainable
development
goals
Keestra et al. SOIL (2016)

24. Societal benefits from soil carbon sequestration
Chabbi et al. NCC (in review)

25. A few caveats….

30. A feasible future: the time of soils
has come….

31. http://www.fao.org/climate-smart-agriculture/en/

32. http://www.fao.org/globalsoilpartnership/en/
The IYS 2015 aims to increase awareness and understanding
of the importance of soil for food security and essential
ecosystem functions.
The IYS website is the main platform to share information
and relevant resources with different partners.
2015
INTERNATIONAL YEAR OF SOILS
http://www.fao.org/globalsoilpartnership/iys-2015/en/

33. The 4 0/00 initiative

34. Conclusions
• Soils are a vital component of resilient agricultural systems (higher
soil carbon makes soils more resilient)
• Soils have a critical role to play in addressing three of the greatest
global challenges: climate change, food security and sustainable
development
• The Climate Smart Agriculture and 4 0/00 initiatives can easily be
aligned
• The lasting legacy of the UN International Year of Soils in 2015
should be put soils at the centre of policy supporting environmental
protection, food security and sustainable development
• Soil scientists must seize the moment, and capitalise on this
unprecedented political interest – and help our global, national and
regional policy makers to improve soils to improve the planet

35. Thank you for your attention