mark howden, steve crimp and many others · anu cci / anu eci • lettuce in semi-arid usa •...
TRANSCRIPT
Will we keep growing food in a hotter and water-constrained Adelaide?
Mark Howden, Steve Crimp and many others
ANU Climate Change InstituteVice Chair, IPCC Working Group II
ANU CCI / ANU ECI
Global temperatures keep rising
ANU CCI / ANU ECI
Warming almost everywhere
NASA 2017
ANU CCI / ANU ECI BoM 2017
Temperatures increasing for SA
ANU CCI / ANU ECI
Extremes: everywhere, all the time
BoM 2017
ANU CCI / ANU ECI
Extremes: this year too
BoM 2017
ANU CCI / ANU ECI
Frost risk increasing too
Crimp et al. 2017
ANU CCI / ANU ECI
Cold extremes: last year too
BoM 2017
ANU CCI / ANU ECI Stephens et al. 2016, BoM 2017
• Rainfall declining in the south
• Increasing in the north
Rainfall zones ‘moving south’
ANU CCI / ANU ECI Data: ABARES. Analysis: Howden 2015
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Fruit: exports vs imports
ANU CCI / ANU ECI
Vegetables: exports vs imports
Data: ABARES. Analysis: Howden 2015
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1985 1990 1995 2000 2005 2010 2015 2020
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ANU CCI / ANU ECI
Managing in a variable and changing climate
‘Past performance is not a reliable indicator of future performance’ – Aust Securities & Investment Commission
‘The past climate is no longer a reliable indicator of the future climate’
–– message from scientific community
ANU CCI / ANU ECI
Emission and temperature scenarios
IPCC 2014
Low emissionsHigh emissions
ANU CCI / ANU ECIHowden et al. 1999
Current heat stress
Heat stress 2.7oC warmer
Heat stress frequency
ANU CCI / ANU ECI
Run-off change per °C warming
median estimate
IPCC 2014
ANU CCI / ANU ECI
Yield variability likely to increase
Porter et al. 2014
ANU CCI / ANU ECI
Climate change adaptations from farmers
van Rees in Crimp et al. 2012
ANU CCI / ANU ECI
• Change species or varieties‒ Silverbeet vs English spinach‒ Californian vs European hops‒ low chill fruit trees vs traditional varieties‒ long-season or short-season‒ lower water use or more drought-tolerant‒ new options: snake beans, kangkong or yams
• Change planting times‒ tomatoes and Melbourne Cup day‒ multiple crops‒ autumn crops
Climate adaptations: urban agriculture
ANU CCI / ANU ECI
• Change in-crop management‒ watering (including monitoring)‒ mulch, shade and frost cover‒ fertilisation‒ weeds, pests, diseases‒ enhance soil carbon
• Change growing systems‒ hydroponics‒ aquaponics
• Change harvest and post-harvest treatment
Climate adaptations: urban agriculture
ANU CCI / ANU ECI
Hydroponics
Picture: Bec Colvin
ANU CCI / ANU ECI
• Lettuce in semi-arid USA• Hydroponics yields (kg/m2) about 10 times higher• Water use only about 8%• But higher energy use (mostly heating and cooling)• More efficient nutrient use too (usually 1/3rd less used)
Hydroponics: yields, water and energy
Barbosa et al. 2015
ANU CCI / ANU ECI
Water balance and efficiency
Soil-based Hydroponics
RunoffSoil evaporation
TranspirationTranspiration
Leaching
ANU CCI / ANU ECI
• Lettuce in semi-arid USA• Hydroponics yields (kg/m2) about 10 times higher• Water use only about 8%• But higher energy use (mostly heating and cooling)• More efficient nutrient use too (usually 1/3rd less used)
Barbosa et al. 2015
Hydroponics: yields, water and energy
ANU CCI / ANU ECI
Sundrop: powered by the sun
ANU CCI / ANU ECI
• Lettuce in semi-arid USA• Hydroponics yields (kg/m2) about 10 times higher• Water use only about 8%• But higher energy use (mostly heating and cooling)• More efficient nutrient use too (usually 1/3rd less used)
Yields, water, energy, nutrient efficiency
Barbosa et al. 2015
ANU CCI / ANU ECI
• Change in-crop management‒ watering ‒ mulch‒ fertilisation‒ weeds, pests, diseases
• Change growing systems‒ hydroponics‒ aquaponics
• Change harvest and post-harvest treatment• Learn and get inspiration from each other
Climate adaptations: urban agriculture
ANU CCI / ANU ECI
• Our climate is changing, more change seems likely• Urban agriculture in Adelaide is already being
affected, with more impacts in store• A range of practical options are available that could
help urban agriculture adapt‒ some are minor changes to existing practices,
others more systemic‒ often multiple benefits‒ all require some level of water security but some
likely much less demanding than others• Urban ag will increasingly be part of providing
nutritious food with a low environmental footprint
Summary
Thankyou
Prof Mark HowdenANU Climate Change [email protected]+61 2 6125 7266
Vice Chair, IPCC Working Group II