1. Long-term trials for climate change
research and adaptation
Eike Luedeling
December 2011

2. Climate change
Rising temperatures
Potential changes in rainfall
Higher variability and more extreme events
Not all of these everywhere, but some of these
somewhere…

3. Climate change
Climate change
Adaptation
Mitigation
Impacts
Resilience
Land use system

4. Climate change
Climate change
Adaptation
Mitigation
Impacts
Resilience
Land use system
Long-term trials are needed for quantifying impacts and mitigation
potentials and for finding robust adaptation strategies

5. Impacts of climate change
Long-term trials, combined with reliable weather
records are essential for understanding system
response to weather
This understanding allows projecting climate change
impacts
For analyzing climate change impacts, all long-term
trials should include weather monitoring

6. Impacts of climate change
Projecting climate change impacts requires thorough
understanding of systems and robust models
Models must be calibrated over wide range of climatic
conditions
Long-term trials allow using long-term weather for
model building, understanding processes well enough
for reliable projections

7. Impacts of climate change
Long-term trials allow using advanced statistical tools
for quantifying system responses
E.g. PLS
regression
No data = no
analysis
Luedeling and Gassner, revision under
review. Agricultural and Forest
Meteorology.

8. Carbon sequestration
Mitigate climate change and pay farmers for C seq.
C Seq. potential?
C stocks
Agroforestry
Agroforestry
Agroforestry
Maize
Maize
Maize
t1 t2 t3

9. Carbon sequestration
Mitigate climate change and pay farmers for C seq.
C Seq. potential?
C Seq. potential?
C stocks
Agroforestry
Agroforestry
Agroforestry
Maize
Maize
Maize
t1 t2 t3
Lower sequestration; less cash for farmers
Long-term trials needed to expose real potential

10. Carbon sequestration
One-off site comparisons may overestimate C storage
potential (hazard for C-selling farmers/projects)
Only long-term trials can show real potential for
carbon sequestration
Provide information on long-term fate of sequestered
carbon, in soil and biomass
Does sequestered carbon survive extreme events?
Data from long-term trials needed for modeling C
sequestration potential ex ante

11. Variability and extreme events
Impacts of extreme events (on non-obvious system
characteristics) can only be evaluated reliably, where
long-term trials exist
Important as baseline, and for ‘putting things in
context’ (are extreme events really so extreme?)
Long-term monitoring can trace system performance
through variability cycles and extreme events, but
they must be there before events happen

12. Adaptation and resilience
Inclusion of wide range of crops / land use options
allows screening for resilience / risks / adaptive
potential
Long-term trials allow evaluation for realistic
variability scenarios
One-off trials only expose adaptation to one
particular manifestation of weather
Develop models based on multi-year performance
that allow testing adaptation options with models

13. Adaptation and resilience
Crop-risk profile
Climate model
Probability (%)
GHG emissions
Time horizon
Crop yield (% of max)
Luedeling 2011. ‘Adaptation to Climate Change and Insurance’ project. Report to GIZ.

14. Trial sites as learning locations
Strategic placement of long-term trial sites
Avoid ‘disappearing climates’
Maximize transferability of results to other sites, now
and in the future
Climate analogue analysis can help determine most
suitable locations

15. Climate analogue analysis
Present climate Future projected climate
Mean of monthly
temperatures ( C)

16. Climate analogue analysis
Climate similarity map
South Sudan Ethiopia
C.A.R.
Somalia
Uganda
Kenya
Congo D.R.C.
Climate Rw.
Target
Bu.
analogue site
location
Tanzania
Angola
Euclidean distance between projected climate at target site and
current climate in the region

17. Climate analogue analysis
Climate similarity map
South Sudan Ethiopia
C.A.R.
Somalia
Uganda
Kenya
Congo D.R.C.
Climate Rw.
Target
Bu.
analogue site
location
Tanzania
Angola
Long-term trials at analogue site can provide information on potential
of land use options for adaptation to one particular climate scenario

18. Climate analogue analysis
Climate analogue map for multiple climate scenarios
Climate projection
C.A.R. South Sudan Ethiopia
Uganda
Kenya
Congo
D.R.C. Rw.
Bu.
Tanzania
Long-term trials at multiple analogue locations allow thorough testing
of crops for climate change adaptation
Such trials allow making robust, climate-change proof empirical
models.

19. Conclusions
Long-term trials are needed for quantitatively
informing impact projections, for assessing mitigation
potentials and for identifying robust adaptation
options.
Trial sites should be strategically placed to provide
useful information for as many locations as possible,
considering projected climate change.

20. Thanks for your attention!
e.luedeling@cgiar.org
December 2011