Geoscience Reference
In-Depth Information
and fibre necessary to sustain human life. Not surprisingly,
agriculture is deemed to be an economic activity that is
expected to be vulnerable to climate variability and change.
The vulnerability of agriculture to climate variability and
change is an issue of major importance to the international
scientific community … stabilisation of greenhouse gas
concentrations in the atmosphere at a level that would pre-
vent serious anthropogenic interference with the climate
system. Agriculture in developed countries may actually
benefit where technology is readily available, along with
the employment of appropriate adaptive adjustments.
10.1
Introduction
The atmosphere surrounding the Earth is made up of nitrogen
(78%), oxygen (21%) and the remaining 1% is made up of trace
gases (called so because they are present in very small quantities)
that include carbon dioxide, methane and nitrous oxide. These
gases, also called greenhouse gases, act as a blanket and trap the
heat radiating from the Earth, thus making the atmosphere warm.
Beginning with the industrial revolution, global atmospheric con-
centrations of these greenhouse gases have increased markedly as
a result of human activities. The global increase in carbon diox-
ide concentration is primarily due to fossil fuel use and land use
change, while those of methane and nitrous oxide are primarily
due to agriculture. As a result, we are witnessing global warming.
The increasing greenhouse gases (GHG) resulted in global warm-
ing by 0.74°C over the past 100 years and 11 of the 12 warmest
years were recorded during 1995-2006. The Intergovernmental
Panel for Climate Change (IPCC) projections on temperature pre-
dicts an increase of 1.8-4.0°C by the end of this century. Some
changes will affect agriculture through their direct and indirect
effect on crops, soils, livestock, fisheries and pests. Tropical coun-
tries are likely to be affected more compared to the countries situ-
ated in temperate regions. The brunt of environmental changes
is expected to be very high in India due to a greater dependence
on agriculture, limited natural resources, an alarming increase in
human and livestock population, a changing pattern in land use
and socio-economic factors that pose a great threat in meeting the
food, fibre, fuel and fodder requirement. There is a likelihood of
a considerable impact on agricultural land use due to snow melt,
availability of irrigation, frequency and intensity of inter- and
intra-seasonal droughts and floods, soil organic transformation
matters, soil erosion and availability of energy as a consequence
