Introduction
Climate change is defined as change in climate over time, whether due to natural variability or
as a result of human activity. Adaptive capacity is the ability of a system to adjust to climate
change (including climate variability and extremes) to moderate potential damages, to take
advantage of opportunities, to cope with the consequences
Vulnerability is the degree to which a system is susceptible to and unable to cope with adverse
effects of climate change including climate variability and extremes new option for carbon
sequestration in agriculture and forestry and land -use change as deforestation contributes to
respectively ,13 and 17 percent of total anthropogenic greenhouse gas emissions while carbon
dioxide emission from agriculture are small the sector account for about 60 percent of all
nitrous oxide (N2O, mainly from fertilizer use) and about 50 percent of methane (CH4, emitted
mainly from natural and cultivated wetlands and enteric fermentation ) .The lpcc estimates
that the global technical mitigation potential for agriculture (excluding foresty) will be between
5 500 and 6 600 mt co2 - equivalent per year by 2030, 89 percent of which are assumed
to be from carbon sequestration in soils .
In India the direct impact of climate change would be effect plant growth development and
yield due to change in rainfall and temperature .Increase in temperature would reduce crop
duration , increase crop respiration rate change the pattern of pest attack and new equilibrium
between crop and pest hasten mineralization in soil and decrease fertilization use efficiency. All
these could considerably affect crop yield for long run. In general the simulation results indicate
that increasing temperature and decreasing growth and yield of agricultural crops. Increased
CO2 levels are expected to favor growth and increase crop yields and therefore, will be helpful
in counteracting the adverse effects of temperature rise in future. On global level climate
change effects will change the crop production areas. In middle and higher latitudes, global
warming will extend the length of the potential growing season, allowing earlier planting of
crops in the spring, earlier maturation and harvesting, the possibility of completing two or more
cropping cycles during the same season.
Crop-production areas may expand pole ward in countries although yields in higher latitudes
will likely be lower due to climate change. Many crops have become adapted to the growing
season, day lengths of the middle and lower latitudes and may not respond well to the much
longer days of the higher summers. In warmer, lower latitude regions, increased temperate
may accelerate the rate at which plant release CO2 in the process of respiration, resulting in
hastened maturation and reduced yield.
Available Water
Agriculture of any kind is strongly influenced by the availability of water. Climate change will
modify rainfall, evaporation, runoff, and soil moisture storage. Changes in total seasonal
precipitation or in its pattern of variability are both important. The occurrence of moisture
stress during flowering, pollination, and grain-filling Is harmful to most crops and particularly so
to corn, soybeans, and wheat. Increased evaporation from the soil and accelerated
transpiration in the plants themselves will cause moisture stress; as a result there will be a need
to develop crop varieties with greater drought tolerance.
Pests and diseases
Conditions are more favorable for the proliferation of insect pests in warmer climates. Longer
growing seasons will enables insects such as grasshopper to complete a greater number of
reproductive cycles during the spring, summer, and autumn. Warmer winter temperatures may
also allow larvae to winter over in areas where they are now limited by cold, thus causing
greater infestation during the following crop season. Altered wind patterns may shift as the
timing of development stages in both hosts and pests is altered. Live stocks diseases may be
similarly affected. The possible increases in pest infestations may bring about greater use of
chemical pesticides to control them, a situation that will require the further development and
application of integrated pest management techniques.
Sustainability and food security
Climate change can impact agricultural sustainability in two interrelated ways: first, diminishing
the long-term ability agro-ecosystems to provide food and fiber for the world’s population; and
second, by inducing shifts in agriculture regions that may encroach upon natural habitats, at the
expense of floral and faunal diversity. Global warming may encourage the expansion of
agricultural activities into regions now occupied by natural ecosystem such as forests,
particularly at mid- and high-latitudes. Forced encroachments of this sort may thwart the
process of natural selection of climatically-adapted native crops and other species.
While the over-all, global impact of climate change on agricultural production may be small,
regional vulnerabilities to food deficits may increases, due problems of distribution and
marketing food to specific regions and group of people. For subsistence farmers and more so
for people who now faces a shortage of food, lower yields may results not only in measurable
economic losses but also in malnutrition and even famine. In general, the tropical regions for
several reasons. On the biophysical side, temperature C3 crops are likely to be more responsive
to increasing levels of CO2. Second, tropical crops are closer to their high temperature optima
and experience high temperature stress, despite lower projected amounts of warming. Third,
insects and diseases, already much more prevalent in warmer and more humid regions, may
become even more widespread.
Inferences
1.
2.
3.
4.
5.
Co2 is increasing
CH4 is increasing
Earth atmosphere system temperature and surface temperature is increasing
Extreme temperature increasing
Atmospheric water vapors content increasing. Frequency of heavy precipitation events
increasing
6. More intense and longer droughts
7. Mid-latitude wide patterns/ storms tracks shifting pole ward.
8. Tropical cyclone intensity increasing.
9. Area of seasonally frozen ground decreasing
10. Glaciers and snow cover decreasing, Arctic sea ice extent decreasing.
Conclusion
1. Plantation should be increasing on the foot of Himalaya, Sahyadri ranges, costal area
and barren land. With reference to Gujarat forest area should increase from9.5% to
20% in next decade or by 2020 AD.
2. For controlling methane emission from the paddy field, the appropriate water saving
technology should be used instead of transplanting and submerged paddy
cultivation method.
3. Shelter belts should be created near sea shore to check salinity and salt nuclei in
atmosphere, which changes rainfall pattern.
4. The simulation results indicate that increasing temperature and decreasing solar
radiation levels pose a serious threat in decreasing growth and yield of agricultural
crops. Increasing CO2 levels are expected to favor growth and increase crop yields
and therefore, will be helpful in counteracting the adverse effects temperatures rise
in future.