3. CLIMATE
“Climate is the aggregate of weather
condition over a long period of time,
the classical period is 30 years, as
defined by the World Meteorological
Organization (WMO).”
4. Climate change
“Any
systematic change in the
long-term statistics of
climate elements (such as
temperature, pressure, or
winds) sustained over
several decades or longer.”
Climate change may be
due to natural external
forcings, such as changes in
solar emission or slow
changes in the earth’s
orbital elements; natural
internal processes of the
climate system; or
anthropogenic forcing.”
(IPCC) 4
5. Two main causes for climate change
Natural Anthropogenic
Natural fluctuations in
the intensity of solar
radiation
Volcanic eruptions
Short term cycles viz.
ENSO (EL NINO)
Burning of fossil fuel emits
CO2
Methane emission from
agriculture and industry
Nitrous oxide emission
from agriculture and
industrial sector
Release of CO2 due change
in land use and land cover.
6. (Source: Kurukshetra, 2008)
Evidences of Climate Change
Physical evidence Biological evidence
1. Rise in atmospheric temp. and CO2 level
2. The precipitation has become spatially
variable
3. Shifting and shrinking of cooling period
4. Changing pattern of monsoon
5. The intensity and frequency of extreme
events has increased
1. Early blossoming of trees
2. Appearance of grasses in
Antarctica
3. Changing cropping pattern
7. Climate Change Scenarios in India
Temperature increased 0.68 0C in the last
century, to increase 1.4-5.80C by 2100
Rainfall to increase 10% by 2050 with an
increased variability causing frequent floods
and droughts
Sea level risen 10-25 cm, to rise 50 cm by 2100
Retreating glaciers in the Himalayas
Shortened rabi season
More incidences of diseases and pests
8. • Average surface temperature may increase by 2 - 4°C during 2050s
• Monsoon rainfall : Marginal changes in monsoon months
• Large changes during non-monsoon months
• No. of rainy days : Set to decrease by more than 15 days
• Intensity of rains : To increase by 1-4 mm/day
• Cyclonic storms : Increase in frequency & intensity
Climate projections
9. Role of agriculture in climate change
The gases which is released from crop field
changes the climate by increasing the
environmental temperature.
The important gases which released from
crop field are-
Carbon dioxide ( CO2 )
Methane ( CH4 )
Nitrous Oxide (N2O )
10. What is the contribution of different sectors
in India to climate change?
(Sources of greenhouse gas emissions in India)
Agriculture
28%
Industrial
processes
8%
Wastes
2%
Energy
61%
Land use
changes
1%
Source: India’s Initial National Communication on Climate Change, 2004
Fossil fuel used in agriculture considered in energy sector
11. What sectors of agriculture in India
contribute to climate change?
Rice cultivation
23%
Manure
management
5%
Emission from
soils
12%
Enteric
fermentation
59%
Crop residues
1%
Source: India’s Initial National Communication on Climate Change, 2004
12. Four Major Greenhouse Gases
Methane
24%
Carbon dioxide
63%Nitrous oxide
10%
Others
3%
13. Industrilization.
Burning fossil fuels - coal, oil, gases, solid waste.
Deforestation (Cutting down and burning of tress)
Burning of organic matter.
Respiration of living organisms.
Human being.
Carbon Dioxide
14. Agricultural sources of methane include flooded rice
paddies, enteric (bacterial) fermentation by
domesticated ruminants (e.g. cows, goats, bison,
sheep, and buffalo), farm animal wastes, and biomass
burning.
Drainage of wetlands for agriculture can also result
in methane emissions, as can thawing of permafrost in
boreal (subarctic and sub antarctic) regions.
Methane (CH4), is a short-lived gas with a low
atmospheric concentration (only 0.5% that of CO2),
however its per-molecule absorption of infrared
radiation is over 20 times stronger than CO2.
Methane ( CH4 )-
15. Nitrous Oxide (N2O )-
In the soil, N2O evolves mainly from the metabolic
process of soil microorganisms.
Factors that determine the level of N2O emissions
include soil aeration, temperature, moisture content, soil
texture and the amount of nitrogen fertilizer.
Nitrous oxide also originates from the decomposition of
livestock manure and other organic residues incorporated
into the soil.
16. The Intergovernmental Panel on Climate Change (IPCC) has
warned that India will continue to experience more extreme
temperature variation with increases in mean annual temperature
Temperature increases range from 3 to 5 degrees Celsius when
using a severe climate scenario and from 2.5 to 4 degrees under
more modest predictions.
Half of the years from 1990 to 2010 have been characterized
climatically as abnormally hot periods, and seven of these hot years
have occurred in the last decade.
Study showed that deviations from India’s mean annual
temperature have been increasing, both in their incidence and
intensity by a mean of 0.4 degrees Celsius.
Temperature Changes in India
17. Temperature and crop growth
All plants have maximum, optimum and minimum
temperature limits. The limits are cardinal temperature
points
Optimum temperature is required for maximum dry
matter accumulation
19. Table -1: Change in Total Crop Duration due to Rise in Temperature
IARI Tripathy, et.al.,2010
20. Crops Temperature rise
1oC 2 oC 3oC
per cent reduction in yield
Wheat 8.1 18.7 25.7
Rice 5.4 7.4 25.1
Maize 10.4 14.6 21.4
Groundnut 8.7 23.2 36.2
Ludiyana Hundal and Kaur, 1996
Table-2 : Effect of increased temperature on productivity of crops in
Punjab
21. Table -3: Interactive effects of CO2 and temperature on yield of
maize and wheat
crop CO 2 ppm
Yield kg/ha
Existing Existing +3
ºC
% Deviation
(+3 ºC)
Maize 350 3700 2337 -36.8
700 4314 3713 -13.8
wheat 350 3916 3339 -14.7
700 6131 5206 -15.08
Punjab kaur et al., 2012
22. 0
10
20
30
40
50
60
70
1 2 3 4 5
Wheat Rice Maize Pearl Millet
Reductioningrainyield(%)
Rise in Temperature (0C)
0
10
20
30
40
50
60
70
1 2 3 4 5
Wheat Rice Maize Pearl Millet
Reductioningrainyield(%)
Rise in Temperature (0C)IARI Tripathy, et.al.,2010
23. Table -5 : Impact of drought on productivity of pearl millet
Station
Pearl millet yield in kg ha-1
% Decrease in
yield
Good monsoon
year (1983)
Mean of 3
drought years
1984-1987
Barmer 285 65 77
Jalore 468 105 77
Jodhpur 337 79 77
Nagaur 721 265 63
Pali 553 248 55
Jodhpur Singh et al., 1999
24. Effect of temperature increase on growth and yield of wheat and rice
Growth
and yield
parameter
Temperature scenarios
Normal +0.5 ºC +1.0 ºC +1.5ºC +2.0 ºC +2.5ºC
Deviation from normal (%)
Wheat
Maximum
LAI
3.76 -5.6 -17.6 -24.6 -30.3 -34.3
Biomass
(Kg ha-1)
13473 -6.6 -13.9 -18.9 -23.3 -28.0
Grain Yield
(Kg ha-1)
5044 -2.8 -9.1 -14.1 -18.1 -23.2
Rice
Maximum
LAI
5.06 -2.5 -5.9 -7.5 -12.0 -17.8
Biomass
(Kg ha-1)
11784 -2.5 -5.0 -6.4 -8.2 -12.6
Grain yield
(Kg ha-1)
7119 -2.6 -4.5 -7.6 -5.6 -14.7
(Mahi 1996)
25. IMPACT OF CLIMATE CHANGE ON
AGRICULTURE
Impact on crop growing period
Duration of crop growth cycles are related to
temperature.
With increase in temperature, the duration between
sowing and harvesting of an annual crop will shorten.
The shortening of such a cycle could have an adverse
effect on productivity, because senescence(aging)
would occur sooner.
26. Impact on yield
Rising carbon dioxide concentration in the atmosphere can have
both negative and positive consequences.
Under optimum conditions of temperature and humidity, the
yield increase could reach 36%, if the levels of carbon dioxide
are doubled.
When rising carbon dioxide concentration will be coupled with
increasing temperature, yield will decrease drastically.
Water deficits will directly affects the crop yield in a negative
manner.
27. Impact on crop quality
Combined increase of temperature and CO2 would decrease
the protein content of the grains of cereals.
Higher CO2 levels lead to reduced plant uptake of nitrogen
and trace elements, resulting in crops with lower nutritional
value.
Reduced nitrogen content in grazing plants has also been
shown to reduce animal productivity.
Small changes in temperature and rainfall would have
significant impact on the quality of fruits, vegetables, tea,
coffee, spices, aromatic and medicinal plants.
28. 28
Potential Impact of Climate Change
on Rice Production in India
Overall, temperature increases are predicted
to reduce rice yields. An increase of 2-4ºC is
predicted to result in a reduction in yields.
Although additional CO2 can benefit crops,
this effect was nullified by an increase of
temperature.
Source: IARI
29. 29
•According to studies, soybean yields could go up by as
much as 50 per cent if the concentration of carbon dioxide
in the atmosphere doubles.
•If this increase in carbon dioxide is accompanied by an
increase in temperature, as expected, then soybean yields
could actually decrease. If the maximum and minimum
temperatures go up by 1°C and 1.5°C respectively, the gain
in yield comes down to 35 per cent.
Effect of Climate change on
Soybean
Source: Centre for science & Environment
30. Impact on soil processes
The increase in temperature would induce a
greater rate in the production of minerals,
lessening organic matter content of the soil.
Due to extremes of climate, the increase in
precipitations would probably result in greater
risks of erosion.
Increase in soil water deficits would lead to
increased need of irrigation.
31. Impact on livestock and fish
production
The warming effect is likely to increase water, shelter, and
energy requirement for the livestock.
Animals could be exposed to higher incidences of heat stress
influencing their productivity.
Increase in the disease transmission due to faster growth of
pathogens in the environment.
The rise in sea and river water temperature would affect fish
breeding, migration, and harvests.
32. Impact on diseases and pests incidence
Increase in rainfall in some areas would lead to increase of
atmospheric humidity, which when coupled with higher
temperature, could favours the development of fungal
diseases and the incidence of insect pests and disease
vectors.
33. Projected impacts of climate change on
Indian agriculture
Productivity of cereals would decrease (due to
increase in temperature and decrease in water
availability (especially in Indo-Gangetic
plains).
Global reports indicate a loss of 10-40% in
crop production by 2100.
Greater loss expected in rabi. Every 1oC
increase in temperature reduces wheat
production by 4-5 million tons. Loss only 1-2
million tons if farmers could plant in time.
34. Increasing temperature would
increase fertilizer requirement for
the same production targets; and
result in higher emissions
Increasing sea and river water
temperatures are likely to affect fish
breeding, migration, and harvests.
Coral reefs start declining from 2030.
Increased water, shelter, and energy
requirement for livestock;
implications for milk production
35. Potential impact of climate change on wheat
production in India
(Aggarwal et al. 2002)
36. Impact of climate change on potato
16
14
12
10
8
6
4
2
0
2020 2050
Year
37. Conservation tillage (Zhou, 1999).
Conventional tillage consumes 60% of tractor fuel and
decrease soil carbon.
Minimum/zero tillage save fuel, conserve moisture, reduce
soil erosion
Globally 150-170 MTC/Yr sequestration is possible
Agricultural soil contains 100-200 tC/ha.
Overuse leads to degradation, salinization, erosion and
desertification and lower OM content with consequent C
emission.
Techniques to reduce GHGS in
Agriculture
38. Paddy rice (Alhgrimm, 1998)
Intermittent flooding and greater use of
inorganic fertilizers
Nitrogenous fertilizers (Kramer et al., 1999)
Slow release fertilizers, organic manures and
nitrification inhibitors: cut 30%
Irrigation scheduling (Schmitz, 1998)
Apply only as needed: saves water and
energy
Cheap and accurate field moisture sensors
(but not available)
39. Develop heat and drought tolerant genotypes.
Develop a compendium of indigenous traditional
knowledge and explore opportunities for its utilization.
Evaluate carbon sequestration potential of different land
use systems including opportunities offered by
conservation agriculture and agro-forestry.
Altering dates of planting, spacing and inputs
management.
40. CONCLUSIONS
Global warming occurs mainly due to human activities.
Changes in climate will have several implications in agriculture,
i.e. change in the location of optimal growing area of particular
crops.
Increase in flood frequencies and accelerated costal erosion,
inundation and salt water intrusion.
Shift in the geographical area of forest in natural ecosystem.
Agriculture scenario is surely going to change due to effect on
photosynthesis, input use efficiency, pest population dynamics,
land use and land cover changes etc.
There is need for intensive research in this regard so that the
sustainability of agriculture can be maintained.