Agriculture Reference
In-Depth Information
16
Global Climate Change
and Agriculture
Roberto César Izaurralde
contents
Abstract .................................................................................................................. 249
Introduction............................................................................................................ 250
Climate Change Impacts on Agriculture................................................................ 252
Plant Growth under Elevated CO
2
..................................................................... 252
Understanding the Effects of Elevated CO
2
and Other Factors on Plant
Growth............................................................................................................... 254
Predicting the Effects of Climate Change on Agricultural Productivity ........... 255
The Role of Agriculture in Climate Change Mitigation and Adaptation ............... 255
Definitions of Mitigation and Adaptation ......................................................... 255
Mitigation of Climate Change through Soil Carbon Sequestration and
Reductions in Greenhouse Gas Emissions........................................................ 257
Adapting Agriculture to Climate Change.......................................................... 259
Toward Agricultural Sustainability in the Twenty-First Century........................... 259
Conclusions............................................................................................................ 260
Suggestions for Study Topics ............................................................................ 260
Note........................................................................................................................ 260
References.............................................................................................................. 260
AbstRAct
The Fourth Assessment Report of the Intergovernmental Panel on Climate Change
released in 2007 significantly increased our confidence about the role that humans
play in forcing climate change. There is now a high degree of confidence that the
(1) current atmospheric concentrations of carbon dioxide (CO
2
), methane (CH
4
), and
nitrous oxide (N
2
O) far exceed those of the preindustrial era; (2) global increases in
CO
2
arise mainly from fossil fuel use and land use change, while those of CH
4
and
N
2
O originate primarily from agricultural activities; and (3) net effect of human
activities since 1750 has led to a warming of the lower layers of the atmosphere, with
an increased radiative forcing of 1.6 W m
−2
. Depending on the scenario of human
population growth and global development, mean global temperatures could rise
between 1.8 and 4.0°C by the end of the twenty-first century. The agricultural sector
is likely to be significantly affected by regional changes in temperature and pre-
cipitation. Overall changes in crop productivity and global food production could be
249
