Geoscience Reference
In-Depth Information
The most noticeable of such events in recent years included
the country-wide drought in 2002, the heat wave in Andhra
Pradesh in May 2003, extremely cold winters in 2002 and 2003,
and prolonged dry spell in July 2004 and January 2005 in the
North, unusual floods in the Rajasthan desert in 2005, drought
in the North-East in 2006, abnormal temperature in January
and February in 2007, and 23% rainfall deficiency in the 2009
monsoon. All these events took a heavy toll on crop output.
Indeed, the silver lining in this dismal scenario is the National
Action Plan on Climate Change, launched in 2008, which aims
at developing technologies to help rain-fed agriculture adapt to
the changing climate patterns. At least four of the eight 'national
missions' started under this programme will have direct or indi-
rect bearing on rain-fed farming. These are the missions on sus-
tainable agriculture, water, green India and strategic knowledge.
The ICAR-led national agricultural research system is also con-
ducting research on specific projects under the umbrella pro-
gramme on climate change. 'Apart from the use of technological
advances to combat climate change, there has to be sound policy
framework and strong political will to achieve this objective',
maintains ICAR scientists. State agricultural universities and
regional farm research centres, too, will have to play a role in
developing local situation-speciic strategies for adapting the
rain-fed farming to emerging climate patterns.
10.3
Global scenario of climate change
Current
scenario
The global atmospheric concentration of carbon dioxide, a GHG
largely responsible for global warming, has increased from a
pre-industrial value of about 280-379 ppm in 2005. Similarly,
the global atmospheric concentration of methane and nitrous
oxides, other important GHGs, has also increased consider-
ably. The increase in GHGs was 70% between 1970 and 2004.
Eleven of the last 12 years rank among the 12 warmest years
in the instrumental record of global surface temperature since
1850. The mean earth temperature has changed by 0.74°C dur-
ing 1906-2005. Most of the observed increase in global aver-
age temperatures since the mid-twentieth century is very likely
due to the observed increase in anthropogenic greenhouse gas
concentrations. During the last 50 years, cold days, cold nights
and frost have become less frequent, while hot days, hot nights
and heat waves have become more frequent. The frequency of
heavy precipitation events has increased over most land areas.
Global average sea level rose at an average rate of 1.8 mm per
