agriculture

1. Climate change and
agriculture: Will extreme
weather leave us hungry?
Brian Thomas
Warwick HRI

2. University of Warwick: Warwick HRI
a Department of Plant and Microbial Sciences
 Crop science applied to sustainable production,
particularly of horticultural crops
 Crop genetics, breeding, crop production, crop protection
 Strong Defra and industry linkages

3. Outline
 Climate change policy and Agriculture
 Climate change research in Warwick HRI
 Predicting extreme weather and crop responses
 Examples and case studies
 The spector of bioenergy
 Conclusions and discussion

4. Policy
 UK target to reduce carbon dioxide
emissions through domestic and
international action by 26-32% by
2020 and 60% by 2050 (1990
baseline)
 Based on 550 ppm CO2 or plus
2oC
 “In the UK, other critical sectors of
the economy where we need to do
more to tackle greenhouse gas
emissions include agriculture and
waste management.”

5. Agriculture and Climate Change
Research
 Emissions from agriculture to air (7% UK greenhouse
gases).
 Mitigating nitrogen and carbon emissions to air.
 Energy in agriculture and food.
 Bioenergy.
 Renewable materials.
 Climate change impacts and adaptations.

6. Energy and water use
 Where does it go?
 Options for improving efficiency
 Energy
Steve Adams
WHRI & Farm Energy Centre
 Water
Andrew Thompson
WHRI & ADAS

7. Overall: Petroleum products = 52%, electricity (primary) = 36%,
gas = 12%, coal = 0.4%, renewables (2005) = <0.1%
0
1000
2000
3000
4000
5000
6000
Protected
crops
Horticultural
field crops
Cereals Potatoes Other arable
crops
Poultry Pigs Dairy Beef and
sheep
Energy
use
(GWh)
Coal
LPG
Oils mobile
Oils static
Gas for CHP
Gas
Electricity
Energy in agriculture

8. Water use in Environment Agency regions
0
10
20
30
40
50
60
70
80
90
100
N
orth
East
N
orth
W
est
M
idlands
Anglian
Tham
es
Southern
South
W
est
Water
usage
(Mm
3
a
-1
)
All livestock
Glasshouse
and Nursery
crops
Irrigation of
field crops
Figure 2. Annual water use by agriculture according to EA regions in England (Mm3 year-1).
The proportion of the total contributed by the three largest sector categories of field irrigation, all
livestock and glasshouse and nursery crops, are shown. Taken from King et al, 2006
Irrigation of field crops
is the largest sector
for abstraction in
regions where water
courses are under
threat
Livestock farming
tends to occur where
water is plentiful

9. Countryside Stewardship at WHRI:
Hedge rows
Margins
Pollen and nectar producers
Arable reversion
Impacts on the delivery of biodiversity through Agri-
Environment Schemes: Bill Finch-Savage

10. Coastal Sites:
Some habitats are threatened
directly, i.e coastal sites
1
2
3
4
5
6
Peak District:
Some species are vulnerable at the edge of their climate zones i.e. if
they require low temperature and/or occupy high mountain habitats
Case study Sites:
Warwickshire:
Other areas are less immediately threatened, but ES management may
need to be altered to allow for climate change

12. Predicted Consequences of
Climate Change for the UK
 Temperatures rise by 2 - 3.5 oC
 Wetter winters, drier summers
 More heatwaves
 Flooding and landslides more
frequent
 Sea level rises

13. Extreme Weather
 Extreme weather events:
Exceeding the critical physiological
and/or physical thresholds for specified
crops, including heat waves, gales or frosts
during sensitive stages of crop development
that may cause crop failure or have a
significant impact on quality.
 Extreme weather impacts:
Weather conditions affecting crop growth
or management and resulting in
substantial reduction in yield or quality.
This could be a consequence of a single
event, e.g. late spring frost, or prolonged
weather conditions, e.g. severe drought or
continues soil wetness.

15. Daily UKCIP02-based climate scenarios
analysis of extreme events and impacts
HadCM3 HadRM3 LARS-WG
Analysis of
extreme events
& impacts
Observations
low resolution, 300 km high resolution, 1 km

16. Modelled temperature extremes
Data from Hadley forecasts then RRes stochastic
weather generator. HadCM3..HadRM3..LARS-WG..
0
1
2
3
4
5
6
7
Jan Mar May Jul Sep Nov
Number
of
days
with
Tmax>30
BS 2050HI 2080HI
(a)
0.0
0.3
0.6
0.9
1.2
1.5
2 4 6 8 10 12
Length, day
Frequency
BS 2050HI 2080HI
Heat-waves
(b)
0.0
1.0
2.0
3.0
4.0
5.0
6.0
2 5 8 11 14
Length, day
Frequency
BS 2050HI 2080HI
Frost-spells
(c)
Fig. 2. Magnitudes and frequencies of extreme weather events: (a) Average number of days per month with maximum
temperature exceeding 30
o
C for the baseline (BS), 2050HI and 2080HI scenarios; Expected frequencies of (b) heat-
waves with temperature exceeding 30
o
C and (c) frost-spells of various lengths in a single year for the baseline (BS),
2050HI and 2080HI scenarios at Rothamsted, UK.

17. Modelled daily preciptation
8
11
14
17
20
23
Jan Mar May Jul Sep Nov
95
precentile
of
precipitation,
mm
BS 2080HI
(a)
25
30
35
40
45
DJF MAM JJA SON
95
percentaile
3-days
precipitation,
mm
BS 2080HI
(b)
Fig.3 (a) 95 percentile of daily precipitation and (b) 95 percentile of 3-days
precipitation for the baseline and 2080HI scenarios at Rothamsted, UK.

18. Crop Type Examples Vulnerable Process
Annual seed crops Cereals, oilseeds,
peas
Planting, establishment,
flowering, seed formation
Annual vegetable
crops
Brassicas,
potatoes
Planting, establishment,
development, quality
Annual Protected crops Tomatoes Quality, yield
Perennial fruit crops Apples Bud break, flower initiation,
flower development, fruit
growth
Perennial Biomass
Crop
Miscanthus Establishment
Sensitivities to extreme weather

19. Extreme Weather Physiological impact Crops affected
High temperatures in
summer
Reproductive (flower)
development impaired
Cereals, oil seeds, peas,
tomatoes, apples
Flower bud formation–
effects seen the following
year
Apples
Crop development and yield
impaired
Vegetable brassicas,
tomatoes
Crop quality impaired Oil seeds, cereals,
tomatoes, apples, vegetable
brassicas
High temperatures in winter Cold hardiness limited Winter cereals, winter
oilseeds, apples
Early bud break and frost
susceptibility
Apples
Effects of high temperature

20. Flowering time in wheat
Baseline 2050HI 2080HI
Avalon Date of anthesis 11 June 26 May 15 May
Probability
27
10
T
ant
P 
0.121 0.154 0.242
Mercia Date of anthesis 19 June 6 June 27 May
Probability
27
10
T
ant
P 
0.114 0.322 0.403
Table 2. Average date of anthesis for cv. Avalon and cv. Mercia and
probability of high temperature after anthesis
27
10
T
ant
P 
for baseline,
2050HI and 2080HI climate scenarios (see details in the text).

21. Winter Cauliflower

22. Phases of development
Juvenility
End of juvenility
Induction
Initiation
Curd growth
Harvest
Germ
Sowing
Emergence

23. 4
8
12
16
20
Early summer
Long-term
average
daily
mean
temperature
(
o
C)
4
8
12
16
20
Summer/autumn
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar
4
8
12
16
20
Winter
Range of time for the start of induction
Range of time of curd initiation
Range of time of curd maturity

24. Weekly Cornish cauliflower
production 1996/1997
Nov Jan Mar

25. Curd induction function for Winter Cauliflower cv Renoir
Parameters for Cornwall
Temperature
o
C
0 2 4 6 8 10 12 14 16 18 20
Rate

26. 1 Jul 15 1 Aug 15 1 Sep 15 1 Oct
Predicted
day
of
maturity
1 Jan
1 Feb
1 Mar
1 Apr
1 May
Plot 1
2020s
1 Jul 15 1 Aug 15 1 Sep 15 1 Oct
1 Jan
1 Feb
1 Mar
1 Apr
1 May
2050s
Model start at the end of the juvenile phase
1 Jul 15 1 Aug 15 1 Sep 15 1 Oct
1 Jan
1 Feb
1 Mar
1 Apr
1 May
2080s
1 Jul 15 1 Aug 15 1 Sep 15 1 Oct
1 Jan
1 Feb
1 Mar
1 Apr
1 May
Base
WINTER CAULIFLOWER running model for cv Renoir in Cornwall with 150 years of data synthesised for Camborne

27. Diamond-back moth – Plutella xylostella
 Migrant pest – cannot overwinter
successfully in UK at present –
but might if it gets warmer
 Development favoured by high
temperatures - optimum 30°and
still thriving at 40°
 Develops insecticide resistance
very readily

28. Diamond-back moth
 Migration depends on conditions at source
(so south-west Europe).
 Recent larger migrations correlated with
higher temperatures in SW Europe
 Wind direction and strength also a factor.
 Scenario – UK overwintering + increased
migration, more insecticides, insecticide
resistance.

29. Diamond-back moth
Lincs 1996
0
20
40
60
80
100
120
140
160
180
200
220
2 May 14 Jun 25 Jul 5 Sep 17 Oct
Moths/trap/day
Kirton Holbeach Donington Butterwick Friskney
Immigration

30. Diamondback Moth simulations for Krton Lincolnshire
2 3 4 5 6 7
Frequency
of
synthetic
years
0
50
100
150 base
2020s
2050s
2080s
Number of generations before
either the first Autumnal frost
or 31 December
2 3 4 5 6 7
Frequency
of
synthetic
years
0
50
100
150
1 February
1 June

32. 26 July 2006 – very dry
This was the week they stopped planting brassicas

33. 17 August 2006 – same plot

34. Hot, dry summer of 2006
 Reduced yields in onion, Brussels sprout, carrot,
beans, cauliflower, peas
 Some peas for freezing left in field
 Fuel costs for pumping irrigation
 Running out of stored water
 Strawberry planting and harvest affected
 Potatoes - association between dry soils at
desiccation and bruising
 Salads – scheduling affected
 Large migration of diamond-back moth

36. European Heat Wave 2003

37. Warm, wet autumn
Delay in potato harvest
Delay in autumn field work
Increased disease in autumn cereals
Clubroot in oil seed rape

38. Warm winter - stored crops
 Potatoes
Increased risk of wet rots, early
sprouting, secondary growth in
stores.
Secondary growth also associated
with lack of irrigation.
 Cabbage
Thrips trapped inside are continuing
to reproduce

39. Warm winter – effects on insects
and plants
 Survival of Nasonovia
ribisnigri adults and
nymphs through January
 Very early captures of
Myzus persicae by
suction traps
 Lack of fruit formation in
blackcurrant

40. Wet winter
Land too wet too work – spring
sowing and planting delayed.

41. Pressures on food supplies
 World population increased from
1.6 to 6 billion last century
 It is projected to rise to 9 billion
by 2042
 Consumption per head will also
increase (change from grain/
vegetables to meat)
 Most good quality land is already
in use 0
1
2
3
4
5
6
7
8
9
Billions
1960 1999 2042
US Census bureau

42. Defra strategy
 Low-Carbon Transport: there is strong potential to transform
our cars, lorries and buses away from relying on fossil fuels.
This can happen through a range of technologies: today biofuels
can be made from sugar beet , corn and other produce; but a
new generation of biofuels is under development which can use
a much wider range of materials including wood and waste, with
even better greenhouse gas savings.

43. Biofuels
 The Renewable transport fuel obligation (RTFO) was
announced in November 2005. It encourages fuel
companies to incorporate biofuel into road traffic fuel
sold through the forecourt at a rate of 5% by 2010/11
(2.5% in 2008/9 and 3.75% in 2009/10).
 Without imports the UK will have to use a substantial
proportion of its 'arable' land (estimated at between
20 and 33%)to meet the RTFO target from home
grown biofuels.
 All that would be needed to provide for 3.5% of our
national road fuel requirement.

44. Biofuels
 The US, Brazil, and the EU alone, will shortly between them, be
using more grain for biofuels than the entire global trade for
grain.
 It takes about 330kg of grain to make enough biofuel to fill a 23
gallon fuel tank, more than the average grain consumption per
capita over an entire year!
 ... global [grain] production has only met consumption once over
the last seven years. In 2006/7, the world will have produced
over 70 million tonnes less than it consumed, drawing down
stocks accordingly.
 Even without the forecast growth in the biofuel industry, the
globe as its agriculture stands at present, cannot meet demand.
 Either performance per hectare (yield) or total cropped area
have to increase on a major scale...
Andersons Management Consultants

45. Conclusions
 Climate change will lead to more periods of
high temperature and periods of heavy rain.
 Unseasonal or extreme weather will have an
increasing impact on crop production
 There are already examples of what to expect
 Modelling can help predict consequences and
guide adaptation.
 Extreme weather in the UK may not in itself
make us go hungry but its impact will
exacerbate other pressures on food supply

46. Acknowledgements
 Mikhail Semenov
 Aiming Qi
 Keith Jaggard
 Rothamsted Research
 Steve Adams
 Rosemary Collier
 Jane Fellows
 Carol Jenner
 Andrew Thompson
 Bill Finch-Savage
 Warwick HRI