Geoscience Reference
In-Depth Information
decline in rainfall since the first half of the nineteenth century
(Nicholson, 1994, 2001). While one may be inclined to think
only in terms of more dramatic weather events such as floods,
droughts, storms and hurricanes, adversely affecting agricultural
production, it is important to note that even small changes in cli-
mate could feasibly have substantial effects, particularly if coun-
tries do not have the necessary technology and/or endowments to
deal with these. Indeed, agronomic models of climate sensitivity
suggest that climate changes in most developing countries are
likely to be harmful and can make agricultural areas less produc-
tive (Reilly et al., 1994; Rosenzweig and Parry, 1994).
In India, an increasing trend in temperature and no signifi-
cant changes in rainfall (with some regional variations) has been
reported during the last 100 years (Mooley and Parthasarathy,
1984; Hingane et al., 1985; Thapliyal and Kulshrestha, 1991;
Rupa Kumar et al., 1992, 1994, 2003; Kripalani et al., 1996;
Pant et al., 1999; Singh et al., 2001; Stephenson et al., 2001;
May, 2002; Singh and Sontakke, 2002; Mall et al., 2006, 2007)
and projected during the last part of the twenty-first century in
the range of 0.7-5.8°C (Bhaskaran et al., 1995; Lal et al., 1995,
2001; Lonergan, 1998; Anonymous, 2001e; Rupa Kumar and
Ashrit, 2001; Rupa Kumar, 2002; Rupa Kumar et al., 2003).
Analyses done for India generally show temperature, heat
waves, droughts and floods and sea levels increasing, while
glaciers decrease, which is similar to that reported by IPCC
(Ninan and Bedamatta, 2012). The magnitude of the change
varies in some cases. However, some regional patterns were
noted. The areas along the west coast, North Andhra Pradesh
and North-West India, reported an increase in monsoon rainfall.
Some places across East Madhya Pradesh and adjoining areas,
North-East India and parts of Gujarat and Kerala (−6% to −8%
of normal over 100 years), recorded a decreasing trend. Surface
air temperature for the period 1901-2000 indicates a significant
warming of 0.4°C over 100 years. The spatial distribution of
changes in temperature indicated a significant warming trend
along the west coast, Central India, interior Peninsula and
North-East India. However, a cooling trend was observed in the
North-West and some parts of Southern India. There is evidence
that the glaciers in the Himalayas are receding at a rapid pace.
It is projected that by the end of the twenty-first century, rainfall
will increase by 15-31% and the mean annual temperature will
increase by 3-6°C. The warming will be more pronounced over
land areas with the maximum increase in northern India. The
warming is also projected to be relatively greater in the winter
and post-monsoon seasons (Ninan and Bedamatta, 2012).
