Geoscience Reference
In-Depth Information
evolution of CO
2
emissions from agriculture is uncertain
(Smith et al., 2007a). Fortunately, stable/declining deforestation
(Anonymous, 2003) and increased adoption of conservation
tillage practices (Anonymous, 2001c) will decrease CO
2
emis-
sion (Smith et al., 2007a).
Regional trends
The magnitude of emissions and relative importance of the dif-
ferent sources vary widely among 10 world regions: developing
countries of South Asia, developing countries of East Asia, sub-
Saharan Africa, Latin America and the Caribbean, Middle East
and North Africa, Caucasus and Central Asia, Western Europe
(EU 15, Norway and Switzerland), Central and Eastern Europe,
OECD Pacific (Australia, New Zealand, Japan and Korea) and
OECD North America, that is, Canada, the United States and
Mexico (Anonymous, 2006a). Non-Annex I countries compris-
ing five regions contributed 74% of total agricultural emissions.
N
2
O emissions from soils primarily due to N fertilisers and
manures were the main GHG source from seven regions, while
CH
4
from enteric fermentation was the main GHG source in the
other three regions (Latin America and Caribbean, the countries
of Eastern Europe, the Caucasus and Central Asia and OECD
Pacific). This was due to 24% and 36% of global sheep and cattle
population in these three regions (Anonymous, 2003).
Rice production emitted 97% and biomass burning emitted
92% of the total world CH
4
emissions in developing countries,
while South and East Asia dominated the emissions from rice
production with 82% and emissions from biomass burning
dominated with 74% in sub-Saharan Africa, Latin America and
the Caribbean. Developed regions with 52% of total emissions
from only manure management were higher than the develop-
ing regions with 48% of total emissions (Anonymous, 2006a).
However, CO
2
emissions and removal from agricultural lands
in these 10 regions are uncertain as some countries reported net
emissions while some reported net removals, but countries from
Eastern Europe, the Caucasus and Central Asia had an annual
emission of 26 MtCO
2
year
−1
in 2000 (Anonymous, 2006b).
The Middle East, North Africa and sub-Saharan Africa
were the highest emitters of GHGs with a combined 95%
increase in the period 1990-2020 (Anonymous, 2006a). The
per capita food production is either declining or at levels lesser
than adequate in sub-Saharan Africa (Scholes and Biggs, 2004)
due to low and declining soil fertility along with inadequate
fertiliser inputs (Sanchez, 2002; Smith et al., 2007a). The rising
wealth of urban populations in this region (South and Central
Africa, including Angola, Zambia, Democratic Republic of
