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 (a) current atmospheric concentrations of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) far exceed those of the pre-industrial era, (b) global increases in CO2 arise mainly from fossil fuel use and land use change while those of CH4 and N2O originate primarily from agricultural activities, and (c) the 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 21st century.
Revised: July 20, 2009 |
Published: January 1, 2009
Citation
Izaurralde R.C. 2009.Global Climate Change and Agriculture. In Adequate Food for All: Culture, Science, and Technology of Food in the 21st Century. 249-262. Boca Raton, Florida:CRC Press: Taylor & Francis.PNNL-SA-59789.