Table 11.4
Estimates of potential global greenhouse gas emission reductions in 2010 and in 2020Historic emission
Historic C
eq
Potential emission Potential emission
in 1990
annual growth rate in reductions in 2010 reductions in 2020
Net direct costs per tonne
Sector
(MtC
eq
yr
−^1
)
1990–1995(%)
(MtC
eq
yr
−^1
)
(MtC
eq
yr
−^1
)
of carbon avoided
Buildings
a
CO
only 2
1650
1.0
700–750
1000–1100
Most reductions are available atnegative direct costs.
Transport
CO
only 2
1080
2.4
100–300
300–700
Most studies indicate net direct costsless than $US 25/tC but two suggestnet direct costs will exceed $US 50/tC.
Industry
CO
only 2
2300
0.4
Energy efficiency
300–500
700–900
More than half available at net negative
Material efficiency
∼
200
∼
600
direct costs. Costs are uncertain.
Industry
Non-CO
gases 2
170
∼
100
∼
100
N
O emissions reduction costs are 2
$US 0–10/tC
eq
.
Agriculture
b
CO
only 2
210
Most reductions will cost between
Non-CO
gases 2
1250–2800
n.a
150–300
350–750
$US 0 and 100/tC
eq.
with limited
opportunities for negative net directcost options.
Waste
b
CH
only 4
240
1.0
∼
200
∼
200
About 75% of the savings as methanerecovery from landfills at net negativedirect cost; 25% at a cost of$US 20/tC
eq
.