This document discusses strategies for combating the ill effects of climate change on soil and crop productivity. It outlines how climate change is impacting agriculture through increased temperatures, changing rainfall patterns, and more frequent extreme weather events. These changes are projected to reduce global agricultural productivity by 1-5% GDP and decrease Indian cereal production by 10-40% by 2100. The document recommends technological innovations like adaptive crop varieties and diversification to help bridge projected yield gaps and reverse climate change impacts. Adaptation and mitigation costs are uncertain but inaction costs may be even higher.

1. Strategies for combating ill effect of
climate change on soil and crop
productivity
Dr. K. Boomiraj
Assistant Professor (Environmental Science)

2. Climate change
 Climate change refers to a statistically significant variation in
either the mean stage of the climate or in its variability,
persisting for an extended period (typically decade or
longer).
 May be due to natural internal processes or external forcing,
or to persistent anthropogenic changes in the composition of
the atmosphere or in land use.

3. Natural and
anthropogenic
contributions to global
temperature change
(Meehl et al., 2004).
Observed values from
Jones and Moberg 2001.
Grey bands indicate 68%
and 95% range derived
from multiple simulations.
Natural cycles

4. Natural and
anthropogenic
contributions to global
temperature change
(Meehl et al., 2004).
Observed values from
Jones and Moberg 2001.
Grey bands indicate 68%
and 95% range derived
from multiple simulations.
Not Natural

5. GHG effect – Necessary Evil
 Green house Gas effect – to maintain the atmospheric
temperature to sustain the life on earth.
 Enhanced GHG effect has detrimental harmful effect on
human beings as well as all living organism
 Anthropogenic activity – Fossil fuel consumption,
deforestration land degradation etc..

6. Projected concentrations of CO2 during the 21st
century are two to four times the pre-industrial level
Year CO2, ppm
2000 369
2010-2015 388-398
2050/2060 463-623
2100 478-1099

8. Global mean temperatures have increased by 0.74oC during last
100 years. The rate has become faster in recent years
Warmest 12 years:
1998,2005,2003,2002,2004,2006,
2001,1997,1995,1999,1990,2000
IPCC, 2007

9. Future Climate is Likely to be Warmer
• Although there is considerable uncertainty about future, all climate
models indicate a rising trend in temperature. By 2100 a rise of 1.8 to
4oC is expected.
• Rise in sea level by 15 – 95cm
• Occurrence of extreme weather conditions
• Severe droughts and floods occur
• Adverse effects on ecological systems
• Effects on human health, economy and quality of life

10. Source: IPCC, 2007
In India, greater warming
is expected in the Indo-
Gangetic plains
Projected warming in 21st century
Warming is expected to be
greatest over land and at
most high northern latitudes

11. Future Climate Change -Temperature In Asia
 Temperature rise in Asia is likely to be:
1.6 +/- 0.20C in the 2020s
3.1 +/- 0.30 C in the 2050s
4.6 + /- 0.40C in the 2080s
 Indonesia, the Philippines and coastal south Asia and Indo-
China: least warming in the islands and coastal areas
 South Asia and Indo-China: greatest warming in inland
continental areas except from June to August in south Asia

12. Proportion of heavy rainfall has increased in most
places
Regions of disproportionate changes in heavy (95% fractile)
and very heavy (99% fractile) precipitation.
IPCC WG-I (2007)

13. Agriculture and climate change
Agriculture is highly integrated into the climate change challenge
Agriculture is one of the main emitters of greenhouse gases
Agriculture is highly impacted by climate change (temperature,
rainfall)
Issues
- GHG emissions (CO2, CH4, N2O)
- Climate change impacts
- Soil quality
- Water usage
- Resilience to climatic variability
- Adaptation to climate change

14. CROP PRODUCTION – WEATHER-DEPENDENT SECTOR
 80% of the world area rainfed and 20% irrigated
agriculture - A good rainy season means good crop
production, enhanced food security and a healthy
economy.
 Failure of rains and occurrence of natural disasters
such as floods and droughts could lead to crop
failures, food insecurity, famine, loss of property
and life, mass migration, and negative national
economic growth

15. Impacts of climate change
 Crop productivity is projected to decrease for even small local
temperature increases (1-20C) at lower latitude, especially
seasonal dry and tropical regions, which would increase the
risk of hunger.
 developing countries are expected to experience larger
percentage losses, global mean losses could be 1-5% GDP for
40C of warming
(IPCC, 2007)
 The rising temperatures and carbon dioxide, and uncertainties
in rainfall associated with global climate change may impact
food production in South Asia due to its large population,
predominance in agriculture, and its limited resource
endowments
( Aggarwal, 2003)

16. Impacts on Crop Productivity
Climate related drivers on crop productivity
1. Elevated carbon dioxide
2. Rainfall and associated water resource
availability
3. Temperature – both direct and indirect through
evaporation
4. Extreme weather events (wind, flood damage)
These interaction to affect crop productivity, quality,
pests and diseases.

17. Contd..
 Doubling of CO2, productivity of C3 crops particularly rice,
soybean, millets and tropical C3 grasses will likely to
increase.
 Rise in temperature as a result of doubling of CO2, C3 crops
like wheat, barley, potato, lentil, mustard and temperate
grasses will likely to be adversely affected.
 Productivity of C4 crops like maize, sugarcane, sorghum and
C4 tropical grasses will be little increased but temperature
will have more negative and rainfall will have variable
effects.

18.  Climate change will have impact on the extinction of
biodiversity species and shift in habitat is likely to occur.
 With the uniform rise of rainfall will have positive impact
on overall agriculture but skewed rise (extreme event) will
have negative impact on soil nutrient loss due to flood
damage and erosion, and will have negative impact on
overall agriculture.
Contd..

19. better winter
survival of pests
more root rots
with heavy rains
Insect, disease and weed
pressure is already changing
perennial
weeds
make
good use
of CO2

20. Some crops will be ‘winners’
Others will be ‘losers’

21. Impact of climate change on Indian Agriculture
 Cereal productivity to decrease by 10-40% by2100.
 1oC increase in temperature may reduce wheat production
by 4-5 mtons (1-2 mtons if adapted).
 Increased droughts and floods are likely to increase
production variability
 Reduced frequency of frost damage: less damage to potato,
peas, mustard
 Some improvement in chickpea, mustard, and rabi maize,
sorghum and millets; and coconut in west coast

22. Impact on Rainfed Sorghum
Sorghum CSH-16
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K. Boomraj and SP Wani, 2010

23. Climate change and soil
• Soil organic matter decrease
• N transformation process affected
• Nutrient imbalances
• Soil biodiversity affected

24. Climate change and desertification
– Increase in drought
– Increased soil salinisation and soil erosion
– Deserts become hotter
Climate change and Biomes
– Increased CO2 absorbed by the sea water forming
carbonic acid affecting corals and other marine
animals
– Habitat changes
– Increased occurrence of diseases

25. Climate change and coastal lowland
• Sea level rise by 2.5cm per decade
• Ingression of sea water – salinisation
• Accelerated coastal erosion
• India soil salinity affects 10 Mha
• In Sundarban, 600 families have migrated due to
sea water ingression

26. Conclusion
 Climate change is a reality and crop productivity is going to
reduce by 40% except some temperate regions.
 Positive effect CO2 enrichment on crop productivity will
be nullified by rise in temperature particularly in the
warmer environment.
 Present level of marginal surplus will continue to decline
and the country may face difficulties to attain agriculture
sufficiency.

27. Contd..
 Technological innovation will be required to bridge the
productivity gap between the actual and the potential.
 Use of adaptive crop varieties, improved seeds including
hybrids, Efficient use of fertilizer and irrigation and crop
diversification will reverse the likely impact of climate
change.
 Costs of adaptation and mitigation are unknown but likely to
be high; costs of inaction could be even higher
 Start with ‘no-regrets’ adaptation options