Agriculture as a Source of GHGs - Climate Resilient Agriculture for Ensuring Food Security - page 38

Fig. 3.4 Estimated historical and projected N 2 O and CH 4 emissions in the agricultural sector of the ten world regions
during the period 1990-2020 (US-EPA 2006a )

(relative to 1990). If demands for food increase,
and diets shift as projected, then annual emis-
sions of GHGs from agriculture may escalate fur-
ther. But improved management practices and
emerging technologies may permit a reduction in
emissions per unit of food (or protein) produced
and perhaps also a reduction in emissions per
capita food consumption.
If CH 4 emissions grow in direct proportion to
increases in livestock numbers, then global
livestock-related methane production is expected
to increase by 60 % up to 2030 (FAO 2003 ).
However, changes in feeding practices and
manure management could ameliorate this
increase. US-EPA ( 2006a ) forecast that com-
bined methane emissions from enteric fermenta-
tion and manure management will increase by
21 % between 2005 and 2020.

The area of rice grown globally is forecasted
to increase by 4.5 % to 2030 (FAO 2003 ), so
methane emissions from rice production would
not be expected to increase substantially. There
may even be reductions if less rice is grown under
continuous fl ooding (causing anaerobic soil con-
ditions) as a result of scarcity of water or if new
rice cultivars that emit less methane are devel-
oped and adopted (Wang et al. 1997 ). However,
US-EPA ( 2006a ) projects a 16 % increase in CH 4
emissions from rice crops between 2005 and
2020, mostly due to a sustained increase in the
area of irrigated rice.
No baseline agricultural non-CO 2 GHG emis-
sion estimates for the year 2030 have been pub-
lished, but according to US-EPA ( 2006a ),
aggregate emissions are projected to increase
by ~13 % during the decades 2000-2010 and