Originally published Vol.
2, Issue 2 (April 2004)
Is Carbon Sequestration in Agriculture
Economically Feasible?
Jan Lewandrowski, Carol
Jones
Increased atmospheric concentrations
of carbon dioxide and other “greenhouse”
gases have contributed to the gradual rise in global
temperatures over the last 50 years. Two options
for reducing the amount of carbon in the atmosphere
are to increase the amount of land planted with
permanent grassland or forest vegetation and to
reduce the frequency or intensity of tillage operations.
Either option would store—or sequester—additional
carbon on the affected lands. In February 2002,
the White House announced a plan to reduce the growth
of U.S. greenhouse gas emissions, in part by developing
incentives for farm and forestland owners and operators
to adopt land uses and management practices that
extract carbon from the air and sequester it in
soils and vegetation.
U.S. agricultural soils have lost,
on average, about one-third of the carbon they contained
before wide-scale cultivation began in the 1800s.
Soil science studies suggest that changes in land
use and land management practices could increase
the carbon content of crop and grazing land soils
by 104-318 million metric tons per year. Forestry
studies suggest that afforestation of cropland and
pasture could add another 91-203 million metric
tons per year.
While the U.S. farm sector’s technical potential
to store carbon is important to know, it is really
the economic potential for storing carbon that is
most directly relevant to policymakers. Using different
incentive payment structures, ERS researchers analyzed
the economic feasibility of increasing carbon levels
in soils and vegetation by providing various levels
of payments to convert croplands and pasture to
trees, shift cropland to permanent grasses, and/or
increase the use of conservation tillage systems.
At payment levels below $10 per
metric ton of additional permanently stored carbon,
landowners find it more cost-effective to adopt
conservation tillage practices, as compared with
other changes to land use and management practices.
At higher payment levels, converting cropland to
trees becomes more cost effective. For payments
equal to $125 per metric ton of additional permanently
stored carbon, farmer adoption of conservation tillage
and afforestation of crop or grazing land could
yield 72-160 million metric tons of carbon, enough
to offset 4-8 percent of gross U.S. emissions of
greenhouse gases in 2001. Converting cropland to
grass did not prove to be a cost-effective option
at any payment level analyzed.
The economic potential, even at
the $125-payment level, is much less than the technical
potential suggested by soil science and forestry
studies because activities that are technically
feasible are not always economically feasible. Furthermore,
the share of the technical potential that is economically
feasible varies greatly across activities because
of the wide variation in the costs farmers would
incur in adopting different carbon-sequestering
land uses and practices.
This
finding is drawn from . . . |
Economics
of Sequestering Carbon in the U.S. Agricultural
Sector, by Jan Lewandrowski, Mark
Peters, Carol Jones, Robert House, Mark Sperow,
Marlen Eve, and Keith Paustian, TB-1909, USDA,
Economic Research Service, April 2004 |
|