PREDICTING CLIMATE CHANGE IMPACTS ON SUGARCANE
PRODUCTION AT SITES IN AUSTRALIA, BRAZIL AND SOUTH
AFRICA
SINGELS A1, JONES M R1, BIGGS J2, MARIN F3, THORBURN P2 AND RUANE A4
1
South African Sugarcane Research Institute, Mount Edgecombe, South Africa
4
2
CSIRO Ecosystems Sciences, Brisbane, Australia
3
Embrapa Agriculture Informatics, Campinas, Brazil
NASA Goddard Institute for Space Studies, New York, USA
E-mail: abraham.singels@sugar.org.za
Abstract
Future climate change is expected to have important consequences for agricultural
production and food and energy security worldwide. Reliable predictions of crop response
to climate change are necessary to plan adaptation strategies. The objective of this study
was to assess simulated sugarcane responses to climate change for three sites, as part of
the AgMIP (Agricultural Model Intercomparison and Improvement Project) methodology for
predicting future climate impacts on, and exploring adaptation options for, regional and
global sugarcane production.
Although the AgMIP protocol follows an ensemble approach (using multiple models to
quantify the uncertainty of estimates), the focus here was to analyse and understand
simulated responses in the crop-soil system to predicted climate change from one global
climate model (GCM) to assess the feasibility of the methodology and suggest possible
improvements to it.
The APSIM-sugar and DSSAT-Canegro sugarcane models were calibrated for three sites
(Ayr in Australia, Piracicaba in Brazil and La Mercy in South Africa). Two 30-year time
series of daily weather data (a recent baseline with atmospheric CO2 concentration, [CO2],
set at 360 ppm and an end-of-the century series with [CO2] set at 720 ppm), were then
used to simulate crop growth and yield using the two crop models. Future weather data
were generated by modifying historical weather records with monthly adjustment factors
derived from the HadCM3 GCM for the A2 greenhouse gas emission scenario of the IPCC.
Yield responses to changes in temperature, rainfall and [CO2] were analysed by
investigating their impacts on phenological development, radiation capture, water use, crop
water status, biomass component growth and yield.
Simulation similarities and discrepancies between crop models and the credibility of
simulated responses to predicted climate change will be discussed, and refinements to the
methodology recommended. Likely implications of changed crop behaviour for agronomic
management will also be discussed.
Keywords: cane yield, climate change, CO2 fertilization effect, crop model, global climate
model, water stress