Legal Pathways to Carbon-Neutral Agriculture

Date01 October 2017
10-2017 NEWS & ANALYSIS 47 ELR 10845
Legal Pathways
to Carbon-
by Peter Lehner and
Nathan A. Rosenberg
Peter Lehner is Senior Attorney and Director of the
Sustainable Food and Farming Program at Earthjustice.
Nathan A. Rosenberg is a Visiting Assistant Professor
at the University of Arkansas School of Law.
is Article, excerpted from Michael B. Gerrard &
John Dernbach, eds.,    -
   (forthcoming in 2018
from ELI), examines the agricultural strategies, prac-
tices, and technologies available to increase soil carbon
sequestration and reduce greenhouse gas emissions. It
details pathways for amending existing federal and
state legal regimes and enacting new ones, and rec-
ommends improving public agricultural research,
development, and extension eorts; reforming federal
subsidy and conservation programs; and revising trade
policy, tax policy, regulatory strategies, nancing for
carbon farming, grazing practices on government
land, and greenhouse gas pricing. It also describes
how the private and philanthropic sectors can stimu-
late carbon farming; strategies for reducing emissions
that stem from farm inputs and that result from food
processing, distribution, consumption, and waste; and
the potential to encourage consumption of climate-
friendly foods through national dietary guidelines,
procurement at all levels of government, and private-
sector initiatives such as certication schemes and
healthier menu options.
I. Introduction
Agriculture is both a source and a sink for greenhouse
gases. Decisionmakers can take full advantage of agricul-
ture’s potential to slow climate change only by acknowl-
edging the sector’s dual role in decarbonizing the economy,
and seeking both to minimize agricultural greenhouse gas
emissions and to maximize ca rbon storage.
Two terms are commonly u sed to describe agricultural
methods that reduce net agricultura l emissions. e rst,
“climate-friendly,” refers to practices or strategies that
reduce greenhouse gas emissions or increase soil carbon
sequestration when compared to conventional methods.
While superior to standard practices, climate-friendly
practices are not necessarily optimal, both in terms of their
climate benets or their overall benet to society. In con-
trast, “carbon farming” describes a suite of climate-friendly
practices and strategies designed to result in optima l envi-
ronmental, societal, and climate outcomes.1
Decisionmakers should prioritize climate-friendly prac-
tices that reinforce carbon farming systems. A lthough
many Republican leaders, as well as rural voters, tend
to ignore or doubt climate science, the many benets of
climate-friendly practices provide independent reasons for
their adoption. A lthough not the norm currently—and
not widely supported by agrochemical companies and
other traditional sources of information—climate-friendly
practices almost a lways improve soil health and thus can
increase farm yield, en hance resilience to climate change,
and often increase protability (especially over the longer
term). us, decisionmakers, regardless of their position on
climate change, should strongly support broader adoption
of these practices to assist farmers and ra nchers and rural
communities, and to protect basic environmental needs
such as clean air and water.
1. “Carbon farmi ng” includes g razing and a nimal husbandr y. E T-
, T C  F S 6 (2016 ). “Regener ative agri-
culture” is another term for largely overlapping agric ultural practices.
  R I., R  O A 
C C.
 
     
    
         
        
          
       
Copyright © 2017 Environmental Law Institute®, Washington, DC. Reprinted with permission from ELR®,, 1-800-433-5120.
is Article begins by examining the on-eld strategies,
practices, and technologies available to increase soil carbon
sequestration and reduce agricultural emissions. It then
details public law pathways—amending existing federal
and state legal regimes and enacting new ones—for reduc-
ing net agricultural emissions. It recommends improving
public agricultural research, development, and extension
eorts; reforming federal subsidy a nd conservation pro-
grams; and revising trade policy, tax policy, regulatory
strategies, nancing for ca rbon farming, grazing practices
on government land, and greenhouse gas pricing.
e Ar ticle also briey describes non-public law
approaches, focusing on how the private and philan-
thropic sectors can stimulate carbon farming; strategies
for reducing upstream emissions—those that stem from
farm inputs—and downstream emissions—those that
result from food processing, distribution, consumption,
and waste; and, nally, the potential to encourage the
consumption of climate-friendly foods through national
dietary guidelines, procurement at all levels of government,
and private-sector initiatives such as certi cation schemes
and healthier menu options.
II. Agriculture’s Role in
Deep Decarbonization
A. Greenhouse Gas Emissions in the Food System
e food system encompasses the full life cycle of food.
In addition to agriculture, this includes activities that take
place o the farm—from the pre-planting conversion of
native grasslands and production of a gricultural chemi-
cals to the post-harvest distribution, consumption, and
disposal of food.2 e food system is responsible for an
estimated 19-29% of both national and global greenhouse
gas emissions.3 Decisionma kers must approach the food
system as a whole to craft laws and policies that address the
system’s full complement of social, nutritional, and envi-
ronmental impacts.
Agriculture refers to the cultivation of crops and the rais-
ing of a nimals for the “4Fs”: food, feed, fuel, and ber. It
accounts for 51% of the country’s total landmass and 61%
of the landmass of the contiguous 48 states, making it the
single largest type of land use in the United States.4 Of the
country’s total 2.3 billion acres, approximately 408 million
acres are in use as cropland, 614 million acres as grassland
pasture and range, and 127 million acres as grazed forest-
land.5 As a result of agricu lture’s large footprint, relatively
small cha nges in agricultural practices, which may have a
modest impact per acre, can signicantly aect this sector’s
contribution to climate change if t hey are widely imple-
2. Sonja Vermeulen et al.,   , 37 A. R.
E’  R 195, 198-202 (2012).
3. Id. at 195.
4. C N  ., E. R S., U.S. D’.  A-
., M U  L   U S, 2007, at 4 (2011)
5. Id.
mented. Small changes can a lso improve farmers’ and
ranchers’ ability to adapt to the changing climate.
A core concept of this Article is that carbon seques-
tration should be added to this list of the funda mental
aims of agriculture, as well as to the federal programs
and policies t hat support it. Achieving climate stability
is as crit ical a human need a s the other functions of agri-
culture. By reducing greenhouse ga s emissions while also
increasing soil carbon stores, agricultural operation s can
make a substantial contribution to decarbonization in
the United States.
1. Greenhouse Gas Emissions From Agriculture
e U.S. Envi ronmental Protection Agency (EPA)
estimates that emi ssions from agriculture account for
approximately 9% of total U.S. greenhouse gas emissions
each yea r.6 Unlik e the energ y and transpor tation sec tors,
which emit primari ly carbon dioxide a s fossil fuels are
burned, crop and livesto ck greenhouse gas emissions con-
sist largely of nitrous oxide and me thane. Nitrous oxide
is a partic ularly potent g reenhouse gas— the average
radiative forcing of nitrous oxide is 265-298 times that
of carbon dioxide over 100 years.7 Nitrous ox ide emis-
sions will also be the primary cause of stratospheric ozone
destruction thi s century.8 Like nitrous ox ide, meth ane is
a power ful greenhouse ga s; the avera ge radiative forcing
of met hane is about 28-34 time s that of carbon dioxide
over 100 years.
In 2015, total agricultura l emissions of nitrou s oxide
and methane amounted to about 520 million metric tons
of carbon dioxide equivalent.9 In other words, a griculture
released an amount of greenhouse gases roughly equiv-
alent to that produced by 111 million automobiles in a
typical year.10 Agriculture is responsible for about 80%
of U.S. nitrous oxide emissions and about 35% of U.S.
methane emissions, only slig htly less than the met hane
emissions of natura l gas and pet roleum extraction, pro-
cessing, a nd distribution.11
e largest source of U.S. agricultural greenhouse gas
emissions is agricu ltural soil management—a series of
practices intended to improve crop yields, including fer-
6. U.S. EPA,      , https:// issions/inve ntory-us-gr eenhouse-gas -emissions-a nd-
sinks (last visited Aug. 1, 2017).
7. I P  C C (IPCC), C
C 2013: T P S B 714 (2014). Table 8-7 pres-
ents these and other “global warming potential” values.
8. Akkihebbal R. Ravishankara et al.,     
  , 326 S 123,
123-25 (2009).
9. U.S. EPA, I  U.S. G G E  S:
1990-2015, at 5-1 (2017).
10. Compare id. with U.S. EPA, G G E F  T
P V (2014) (a typical passenger vehicle emits 4.7 metric
tons of carbon dioxide annually).
11.  U.S. EPA,       ,
https:// gemission s/overvie w-greenho use-gase s#nitrous-
oxide (last visited Aug. 1, 2017); U.S. EPA,  
Methane Emissions,
house-gases#methane (last visited Aug. 1, 2017).
Copyright © 2017 Environmental Law Institute®, Washington, DC. Reprinted with permission from ELR®,, 1-800-433-5120.
10-2017 NEWS & ANALYSIS 47 ELR 10847
tilization, tillage, d rainage, irrigation,
and fallowing of land.12 Soil manage-
ment generates 48% of all U.S. agri-
cultural emissions and 93% of all U.S.
nitrous oxide emissions.13 Seventy-four
percent of nitrous oxide emissions
from agricu ltural soil management
come from cropland and 26% come
from grazed grasslands.14
e next largest source of agricul-
tural emissions is enteric fermenta-
tion, which results from the digestive
process of ruminants (largely cows and
sheep in the United States). Enteric
fermentation creates methane, which
animals subsequently release into the
atmosphere through belching and
exhalation.15 Enteric fermentation is
responsible for 32% of all agricultural
emissions a nd 25% of methane emis-
sions in the United States.16
Manure management activities are
the third major category of U.S. agri-
cultural emissions, releasing nitrous oxide and methane in
quantities that total 16% of total U.S. agricultural emis-
sions.17 Intensive livestock facilities, colloquially known
as factory farms and called concentrated animal feeding
operations (CAFOs) by federal law, generate the substan-
tial majority of these emissions.
Methane emissions released from soils ooded for rice
cultivation and the eld burning of crop residues make up
an additional 2% of total U.S. greenhouse gas emissions
from agriculture.18 In 2015, EPA included c arbon dioxide
emissions from urea fertilization and liming in its estimate
of agricultural emissions for the rst time.19 Together,
these two sources are responsible for less than 2% of ag ri-
cultural emissions.20
e vast majority of agricultura l emissions are related to
animal production. is is due, in part, to the large amount
of land used to grow animal feed: approximately one-half
of all har vested cropland is devoted to feed crop produc-
tion.21 is cropland is often cultivated more intensely
12. EPA, supra note 9, at 5-21, 5-22.
13. See id. at 5-2.
14. See id. at 5-24 tbl. 5-15.
15. Andy orpe, Enteric Fermentation and Ruminant Eructation: e Role (and
Control?) of Methane in the Climate Change Debate, 93 C C
407, 411 (2009).
16. See EPA, supra note 9, at ES-15, 5-2.
17. See id. at 5-2 tbl. 5-1.
18. See id.
19. See id.
20. See id.
21. ere were approximately 310 million acres of harvested cropland in 2007
according to the Census of Agriculture. N’ A. S S., U.S.
D’  A., 2007 C  A: U.S. N L D
16 tbl. 8 (2009). e U.S. Department of Agriculture (USDA) estimates that
approximately 165 million of those acres were devoted to feed crops; however,
up to 10% of the feed was diverted to biofuels. N  ., supra
note 4, at 20. is total does not include soybeans, which USDA considers a
“food crop,” despite the fact that soybean meal is typically used as animal feed.
than cropland growing human food, with the result that
feed crop production can emit more nitrous oxide per acre
than the production of crops for human consumption.22
Moreover, feed crop cultivation produces more calories
per acre than human food crops, with the result that non-
human animals eat t wo-thirds of the calories derived from
crops grown in the United States. However, only a fraction
of those crop calories are delivered to humans bec ause, for
example, the production of one pound of beef from feedlot
cattle requires 15-20 pounds of grain.23
us, despite the greater use of resources devoted to ani-
mal production,24 humans receive only 30% of their calories
from animal products.25 Because grazing and feed crop pro-
duction contribute almost two-thirds of nitrous oxide emis-
sions from agricultural soils,26 and because animals are the
T L  ., E. R S., USDA, M F A
G S  P T P (2016).
22. Conventionally grown feed crops, such as corn, soybean, and hay, generally
result in high nitrous oxide emissions. See EPA, supra note 9, at 5-23.
23. e feed conversion ratio expresses the number of pounds of grain neces-
sary to increase the “live weight” of a head of cattle by one pound. At in-
dustrial feedlots, a feed conversion ratio of 6:1 is common. D W. S,
B C F E 3 (2013). irty to forty percent of the live
weight of a head of cattle is sold as beef, which means that 15-20 pounds
of grain is necessary to yield one pound of beef. See R H  .,
U.  T. I.  A., H M M  E F 
B C 9 (PB-1822).
24. See Emily Cassidy et al., Redening Agricultural Yields: From Tonnes to People
Nourished Per Hectare, 8 E. R. L 1, 4 (2013). is gure is
based on data from 1997-2003. Biofuel production has increased rapidly
since then, likely resulting in a lower proportion of crops devoted to either
feed or food.
25. USDA Econ. Research Serv., Seventy Percent of U.S. Calories Consumed in
2010 Were From Plant-Based Foods,
chart-gallery/gallery/chart-detail/?chartId=81864 (last updated Jan. 6, 2017).
26. is includes grassland emissions, which account for 65.6 million metric tons
of carbon dioxide equivalent (MMT CO
eq.), as well as 48% of cropland
emissions—the approximate percentage of harvested cropland devoted to feed
crop production in 2007—which adds an additional 89 MMT CO
eq. Com-
Soil Management
Enteric Fermentation
Manure Management
Rice Production
Urea Fertilization
Field Burning
11.2 0.4
Fig. 1. Major Sources of Agricultural
Emissions in the United States
Copyright © 2017 Environmental Law Institute®, Washington, DC. Reprinted with permission from ELR®,, 1-800-433-5120.

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