Introduction
Climate change refers
to any change in climate over time, whether due to natural variability or as a result
of human activity. Our climate is changing day by day and these changes are due
to two main reasons, the first and the foremost is due to emissions of green house
gases to atmosphere and is intervention of human activities such as burning of
fossil fuels and agricultural activities has increased the amount of green
house gases in atmosphere in recent times. There is a strong evidence to
suggest that change in global climate has been occurring during the past 100
years. The mean global temperature has increased by 0.6 0C during
the above period and the warmest summer were observed in the last decade of the
past century and again during 2002 and 2003 especially in Asian Sub-continent
and Europe. This is mainly attributed by Green house gases viz; Carbon dioxide,
Methane, nitrogen oxide and halocarbons. If the emission of Green house gases
is continued at the current rate, the average global surface temperature would
rise from 0.6 to 2.5 0C in the next 50 years and between 1.4 to 5.8 0C
by the end of the century.
Despite
several negative impacts, there are a few beneficial aspects of enhanced green
house gas effects e.g. higher atmospheric concentration of CO2 may enhance
the crop production of crops like rice, wheat and soybean.
Climate change impact on Agriculture
Agriculture is the
major land use across the globe. Agriculture production is highly dependent on
climate since crop growth is influenced by solar radiation, temperature and precipitation.
Agriculture is also sensitive to climatic variability and weather extremes (drought,
floods, and severe storms)
Climate
change is projected to have an effect on local agriculture and the net result
could be harmful e.g. frequent droughts, salinization of agriculture land or
beneficial e.g. enhance CO2 and higher yield, longer growing
season, increased precipitation. Though climate change due to green house gas
emission could cause several effects on agriculture production but agriculture
sector itself is responsible for global green house gas emission contributing
about 25% carbon ( due to deforestation), 50% methane ( due to
rice and livestock production)75% nitrous oxide ( due to use of nitrogen fertilizers).
The impact of Global warming on
agriculture front differs among the countries. In India, the coastal regions of
Gujarat and Maharashtra are worst affected due to inundations on saline waters.
In African countries increased droughts could seriously reduced the food
production and millet yields may decline by 63-79%. In the cooler part of Asia
and China, the rice, wheat and maize yield will probably decline in coming
days.
Factors relating to future Agriculture Production
Several factors are directly related to
climatic change and agricultural productivity including:
1.
Increase of average temperature
2.
Rising of atmospheric temperature
3.
Precipitation , Water cycle availability
and irrigation
4.
Change in climate variability and
extreme events
5.
Rises in sea level
6.
Pests and disease
Adaptation measures
There are many
adaptation options available to counter act projected climatic impacts on
agriculture. These include use of heat/drought tolerant and salt tolerant crops
for greater tolerance to heat stress. The other measures that may be considered
are better farm management practices, diversification of crop cultivars, shifting
cropping seasons and improved farm technologies. The adaptation measures would
significantly improve Gross domestic product.
1.
Use of more heat/drought tolerant crop
varieties
2.
Use of more disease and pest tolerant
crop varieties
3.
Altered application of
nutrients/fertilizers
4.
Altered application of
insecticides/pesticides
5.
Introduce higher yielding, early maturing
crop varieties in cold regions
6.
Change planting date to effectively use
the prolonged growing season and irrigation.
7.
Altering amounts and timings of
irrigation and other water management practices.
8.
Develop adaptive management strategy at
farm levels.