Agriculture Reference
In-Depth Information
15.2 GENERAL EFFECTS OF CLIMATE CHANGE ON WEATHER
PARAMETERS AND ATMOSPHERE
15.2.1 INCREASED AIR TEMPERATURE
This is due to higher GHG in the air since carbon absorbs more heat. Tem-
peratures are increasing from March onwards throughout North and Cen-
tral India and in first week of April, 42-45ºC is recorded in most parts of
this region in the country.
15.2.2 ERRATIC RAINFALL
Global warming has affected ocean wind current intensity and directions.
Slowly and steadily annual rainfall is moving towards deficit with erratic
monthly trend. Distribution of rainfall is disturbed and more rains are re-
ceived in July-August and sometimes extending in to September-Octo-
ber. It disturbs entire crop cycle in the year. Higher rains/cloud bursts are
causing floods in some parts and in other parts deficit rains are causing
drought. There is a shift in rain pattern. Monsoon is arriving late in cen-
tral and North India and 10-15% less rains received since last few years.
There is a heavy downpour at some places while some places are dry. In
central part of India very less or negligible rains are received in June and
there is a deficit of 5% in July. Heavy rains are received in August causing
floods in some parts. Precipitation trend during last 30 years in Vidarbha
indicated that average rainfall is 1000 mm but actually average rainfall
received during last 10 years is 772 mm with annual deficit of 256 mm
(Huchche et al., 2010). There is a significant shift in distribution and total
precipitation received during last 10 years. It has detrimental effect on cit-
rus industry of Vidarbha. Ground water table has gone down substantially
in this part of the country.
It was observed that monsoon rainfall during 1901 to 2003 was without
any trend and mainly random in nature over a long period of time, par-
ticularly on the all India time scale
(Table 15.1)
.
But on the spatial scale,
existence of trends was noticed. The monsoon rainfall in sub-Himalayan
West Bengal and Sikkim and the Bihar Plains are having decreasing trends
while Punjab, Konkan and Goa, West Madhya Pradesh and Telangana are
having increasing trends (Guhathkarta and Rajeevan, 2006).
