Climate Risks and the Productivity Challenge in Field Crops. Graeme Hammer UQ, QAAFI Centre for Plant Science

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1 Climate Risks and the Productivity Challenge in Field Crops Graeme Hammer UQ, QAAFI Centre for Plant Science

2 Productivity Needs Significant advance in productivity needed to meet population growth and increased affluence of emerging economies Opportunities via crop improvement and removing yield gaps but climate risks interfere Is it possible to enhance productivity given existing and changing climate risks?

3 Climate Risks Climate risks pervade agricultural system productivity Their effects are etched into Australian culture From the bush poet Said Hanrahan John O Brien 1921 "We'll all be rooned," said Hanrahan, In accents most forlorn, Outside the church, ere Mass began, One frosty Sunday morn.... "If we don't get three inches, man, Or four to break this drought, We'll all be rooned," said Hanrahan, "Before the year is out... In God's good time down came the rain; And all the afternoon On iron roof and window-pane It drummed a homely tune.. And every creek a banker ran, And dams filled overtop; "We'll all be rooned," said Hanrahan, "If this rain doesn't stop."

4 The Nature of Climate Risks Seasonal climate variability dominates climate risks Annual rainfall (mm) Miesso, Ethiopia - Mean 766 mm Roma, Australia - Mean 597 mm

5 The Nature of Climate Risks Seasonal climate variability induces risks that restrict productivity e.g. risk-productivity trade-off developed & subsistence systems Break-even A key issue with crop adaptation and removing yield gaps! Climate Risk Management for a rainfed agricultural production system. (Baethgen 2010 Crop Sci)

6 The Nature of Climate Risks Seasonal variability has interannual, decadal, and trend components Percent of total June- August precipitation variance attributable to decadal-scale variability. The inset shows decomposition into trend, decadal and interannual components of variability for region indicated by the red box. International Research Institute for Climate and Society (IRI) Time Scales Map Room, Greene et al Eos, Vol. 92, No. 45

7 The Nature of Climate Risks Seasonal climate variability components have some degree of predictability I. ENSO and interannual Stone et al (1996) Nature, 384

8 The Nature of Climate Risks Seasonal climate variability components have some degree of predictability II. IPO and decadal

9 The Nature of Climate Risks Seasonal climate variability components have some degree of predictability III. Predictability remains probabilistic e.g. IRI tercile distribution shift

10 The Nature of Climate Risks Climate trends introduce more uncertainty and reduce the relevance of experience I. CO 2 emissions and global temperature Observed CO 2 emissions and future scenarios Keenlyside, Latif et al Nature 2008 our results suggest that global surface temperature may not increase over the next decade, as natural (decadal scale) climate variations offset the projected anthropogenic warming

11 The Nature of Climate Risks Climate trends introduce more uncertainty and reduce the relevance of experience II. GCMs and Australian rainfall projections - rainfall projections (2050) differ by model - uncertainty related to natural variability

12 The Nature of Climate Risks II. GCMs and temperature projections less uncertain IPCC (2013), WG1, SPM

13 Climate Risks and Productivity NE Australia So uncertainty on seasonal forecasts and climate change effects remains Climate risks prevail! How to move forward? Characterise likely frequencies of future cropping environments relative to current as a basis to explore adaptive strategies encompassing climate risks Consider an example of modelling analysis for sorghum in NE Australia (Lobell et al 2015)

14 Climate Risks and Productivity NE Australia Analysis for sorghum in NE Australia Historical and future climate 15 sites daily weather 33 GCMs for projections using RCP8.5 forcing to 2030, 50, 70 Crop model simulations APSIM sorghum model Range of sowing dates, antecedent soil water, agronomy Water use efficiency increased for high CO 2 Characterisation of drought and heat Crop water status trajectory through life cycle High temperature effect on seed set around flowering Hammer et al. (2010) J Exp Bot; Hammer et al. (2015) Crop and Past Sci Chapman et al (2000) Crop and Past Sci; Singh et al (2015) Field Crops Res

15 Climate Risks and Productivity NE Australia Analysis for sorghum in NE Australia 0.5 o C per decade increase in summer temperature Oct-Mar Apr-Sep

16 Climate Risks and Productivity NE Australia Analysis for sorghum in NE Australia Future impacts on drought and heat frequencies More heat, more (drought + heat) Small decrease in drought (CO 2 effect)

17 Climate Risks and Productivity NE Australia Analysis for sorghum in NE Australia Future impacts increasing importance of heat tolerance on yield impact

18 Climate Risks and Productivity NE Australia Analysis for sorghum in NE Australia Implications climate risks prevail high natural rainfall variability and projected trends largely within that variability significant increasing temperature trend drought effects remain dominant but reducing trend due to CO 2 fertilisation adaptation to water limitation remains central to productivity challenge increasing importance of tolerance to heat stress R&D focus on adaptation to water limitation remains central enhanced R&D focus on heat tolerance appropriate

19 Climate Risks and Productivity Broad Implications Local context and relevance is critical in the field crop productivity challenge think globally, act locally local systems analysis of options Dealing with the productivity-risk trade-off is central to advance multi-season instruments taking advantage of good seasons climate risk awareness and prediction Anticipation of climate trends is important for system adaptation issues beyond relevance of experience (heat tolerance) must consider uncertainty in projections and relate it to natural variability its not all about rainfall temperature and vpd issues Are there opportunities to take more than passive advantage of high CO 2?

20 Acknowledgements High Temperature and Drought Risk Research Team Vijaya Singh, Erik van Oosterom, Chuc Nguyen, David Jordan, Graeme Hammer (UQ/QAAFI) Scott Chapman, Bangyou Zheng (CSIRO) Greg McLean (DAF) This research was part of a Federal Govt DAFF-funded project with support for modelling aspects through a GRDC project. McMaster Fellowship CSIRO/UQ David Lobell (Stanford) Scott Chapman, Bangyou Zheng (CSIRO) Graeme Hammer, Karine Chenu (UQ/QAAFI) Greg McLean (DAF)

21 Climate Risks and the Productivity Challenge in Field Crops Graeme Hammer UQ, QAAFI Centre for Plant Science

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23 Climate Risks and Productivity NE Australia Analysis for sorghum in NE Australia current and future drought type frequencies Simulated environment types Current & future frequencies (no CO2 effect) Current & future frequencies (including CO2 effect) Excluding CO 2 effects, increased frequency of drought stress

24 Climate Risks and Productivity NE Australia Analysis for sorghum in NE Australia current and future drought type frequencies Simulated environment types Current & Simulated future frequencies frequency of mod-severe Current ETs & future (3-5) frequencies (no CO2 effect) (including CO2 effect) With CO 2 effects, consistent small decrease in frequency of drought stress

25 Climate Risks and Productivity NE Australia Analysis for sorghum in NE Australia current and future heat effects Singh et al. (2015) Field Crops Res Increased frequency of seed loss due to heat - about 5% increase per decade

26 Climate Risks and Productivity NE Australia Analysis for sorghum in NE Australia Future impacts drought still important, heat impacts increasing if no adaptation