Agriculture in 2050: Recalibrating Targets for Sustainable Intensification

Abstract

The prevailing discourse on the future of agriculture is dominated by an imbalanced narrative that calls for food production to increase dramatically—potentially doubling by 2050—without specifying commensurate environmental goals. We aim to rebalance this narrative by laying out quantitative and compelling midcentury targets for both production and the environment. Our analysis shows that an increase of approximately 25%–70% above current production levels may be sufficient to meet 2050 crop demand. At the same time, nutrient losses and greenhouse gas emissions from agriculture must drop dramatically to restore and maintain ecosystem functioning. Specifying quantitative targets will clarify the scope of the challenges that agriculture must face in the coming decades, focus research and policy on achieving specific outcomes, and ensure that sustainable intensification efforts lead to measurable environmental improvements. We propose new directions for research and policy to help meet both sustainability and production goals.

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doi:10.1093/biosci/bix010 Advance Access publication 22 February 2017
Agriculture in 2050: Recalibrating
Targets for Sustainable Intensification
MITCHELL C. HUNTER, RICHARD G. SMITH, MEAGAN E. SCHIPANSKI, LESLEY W. ATWOOD, AND
DAVID A. MORTENSEN
The prevailing discourse on the future of agriculture is dominated by an imbalanced narrative that calls for food production to increase
dramatically—potentially doubling by 2050—without specifying commensurate environmental goals. We aim to rebalance this narrative by
laying out quantitative and compelling midcentury targets for both production and the environment. Our analysis shows that an increase of
approximately 25%–70% above current production levels may be sufficient to meet 2050 crop demand. At the same time, nutrient losses and
greenhouse gas emissions from agriculture must drop dramatically to restore and maintain ecosystem functioning. Specifying quantitative targets
will clarify the scope of the challenges that agriculture must face in the coming decades, focus research and policy on achieving specific outcomes,
and ensure that sustainable intensification efforts lead to measurable environmental improvements. We propose new directions for research and
policy to help meet both sustainability and production goals.
Keywords: food demand, crop yield, food security, environment, policy
The prevailing discourse on the future of agriculture
is rife with the assertion that food production must
increase dramatically—potentially doubling by 2050—to
meet surging demand. Many authors also call for agricul-
ture to become more environmentally sustainable, but with
little urgency and few quantitative targets. The result is an
imbalanced narrative that heavily privileges production
over conservation. This imbalance persists despite calls
in the growing sustainable intensification (SI) literature
to treat food production and environmental protection as
equal parts of agriculture’s grand challenge (Robertson and
Swinton 2005, Garnett etal. 2013, Pretty and Bharucha 2014,
Rockström etal. 2017).
We aim to rebalance this narrative by laying out quan-
titative and compelling SI targets for both production and
the environment. These goals will clarify the scope of the
challenges that agriculture must face in the coming decades,
focus research and policy on achieving specific outcomes,
and ensure that SI efforts lead to measurable environmental
improvements.
Our targets are based on the following standards: (a) SI
production goals should aim to meet projected global food
demand while recognizing that factors beyond aggregate
production also affect hunger and malnutrition (FAO etal.
2015, Schipanski etal. 2016), and (b) SI environmental goals
should aim to restore and maintain ecosystem functioning
in both managed and natural systems (Neufeldt etal. 2013,
Rockström etal. 2017).
Many authors call for production increases of 60%–100%
by 2050, based on two recent food-demand projections
(Tilman et al. 2011, Alexandratos and Bruinsma 2012).
These goals appear clear and compelling, but they exag-
gerate the scale of the production increase needed by 2050
because they misinterpret the underlying projections and
ignore recent production gains. Moreover, the projections
are often simplified into a goal of doubling yields, which
serves as an urgent rallying cry for research, policy, and
industry (Monsanto 2008, Foley et al. 2011, Tilman et al.
2011, Ray etal. 2013, Long etal. 2015, Buckley 2016). This,
in turn, fosters a produce-at-all-costs mentality, which may
exacerbate existing environmental challenges by increasing
the use of fertilizers, pesticides, irrigation, and tillage.
In contrast, current SI environmental targets are unclear
and unlikely to inspire action. Most authors agree that
uncultivated land should not be converted for crop produc-
tion (e.g., Garnett etal. 2013, Pretty and Bharucha 2014).
Beyond this, however, stated goals diverge. They range
from the basic—not “increasing agriculture’s environmental
footprint” (Buckley 2016)—to the more aggressive—“major
reductions in environmental impact” (Garnett etal. 2013).
Some sustainability goals would even result in increased
environmental degradation, such as when marginal reduc-
tions in per-unit impacts are coupled with doubled output
(Monsanto 2008).
Our analysis shows that, largely because of recent produc-
tion gains, an increase of approximately 25%–70% above
AQ1
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Figure 1. Food demand is projected to climb, while environmental impacts must
plummet. Calls to double crop production from a recent baseline imply growth
rates outside of the range of empirical projections. Meanwhile, agriculture’s
environmental impacts need to fall rapidly to protect critical ecosystem
functions. (a) Historical and projected global cereal production and demand
(inpetagrams). (b) Historical and projected direct greenhouse gas (GHG)
emissions from agriculture and 2050 goal. (c) Historical total phosphorus loading
in the Mississippi–Atchafalaya River Basin and 2035 goal (in gigagrams).
Historical data are shown in solid lines, and future projections and goal
trajectories are shown in dashed or dotted lines (see supplemental tables S1 and
S3). Pg, petagram; Gg, gigagram. Sources: MRGMWNTF 2015, Foley etal. 2011,
Tilman etal. 2011, Alexandratos and Bruinsma 2012, USGS 2015, FAO 2016.
current production levels may be suf-
ficient to meet 2050 demand (figure 1a,
supplemental table S1). Calls to double
food production from today’s levels are
not supported by existing projections.
Although even a 25%–70% increase will
be challenging, global agricultural out-
put is at least on the right trajectory.
In contrast, agriculture’s environmental
performance is going in the wrong direc-
tion: Aggregate impacts are increasing
and must drop sharply over the com-
ing decades (figure 1b–c, supplemental
tableS3).
We review and update the main pro-
jections of world food demand, discuss
examples of environmental improve-
ments needed by 2050, and propose
new directions for research and policy
to help meet both sustainability and
production goals. Our objectives are
to clarify the overarching productivity
and environmental goals of SI and to
recalibrate the narrative on the future
of agriculture. Therefore, we do not
address the related social, economic,
and geopolitical dimensions of SI (Loos
et al. 2014, Pretty and Bharucha 2014,
IPES-Food 2016); heterogeneity among
regions (Alexandratos and Bruinsma
2012, Mueller etal. 2012, Cunningham
etal. 2013, van Ittersum etal. 2013); or
the merits of different management phi-
losophies (Cassman 1999, IAASTD 2009,
Bommarco et al. 2013, Tittonell 2014).
Rectifying the prevailing SI narrative is
crucial because it is already shaping the
future of agricultural research and policy
(e.g., USDA 2015, Buckley 2016), with
potentially dramatic consequences for
the future of food production and the
environment.
Food-demand projections
Food demand in 2050 is projected to rise
as the global population crests 9.7 billion
people (UN 2015) and greater wealth
drives up per-capita consumption, espe-
cially of resource-intensive animal prod-
ucts (Alexandratos and Bruinsma 2012).
Public and scientific discourse on the
subject focuses primarily on two stud-
ies (Tilman et al. 2011, Alexandratos
and Bruinsma 2012). First, Alexandratos
and Bruinsma (2012) of the United
Nations (UN) Food and Agriculture
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Organization (FAO) projected a 60% increase in demand
from a 2005/2007 baseline using a price-weighted index of
food commodities. Second, Tilman and colleagues (2011)
projected that demand for calories and protein from human-
edible crops will increase by 100% and 110%, respectively,
from a 2005 baseline. Both of these projections account for
crops used as animal feed and, to a limited extent, as biofuel
feedstock.
These projections are complex and are commonly mis-
interpreted. First, the FAO projection of a 60% increase is
frequently misquoted as a 70% increase when authors cite an
earlier FAO report (Alexandratos 2006). Second, the price-
weighted basis of the FAO figures implies a larger increase
in crop demand than is actually projected on a mass basis:
For example, FAO projects only a 46% increase in cereals
demand (Alexandratos and Bruinsma 2012). Most impor-
tantly, authors often ignore the base year of the projections
(Foley etal. 2011, Ray etal. 2013, Long etal. 2015, Daryanto
etal. 2016), implying that the projected increase must occur
from today’s production levels. For both of these projec-
tions, the base year is now a decade past, and production has
increased substantially in this time (table S1). This error is
particularly misleading when authors explicitly graph 2050
demand as a doubling from current levels (e.g., Long etal.
2015).
We use global demand for cereals as a proxy for total
crop demand to illustrate the production increase needed
by 2050. Cereals are the world’s dominant crops. In 2013,
they were grown on 47% of global cropland and provided
63% and 56% of calories and protein, respectively, from
human-edible crops (table S3; FAO 2016). Of course, ending
hunger and malnutrition will require multiple crop types,
including pulses, roots, vegetables, and fruits, many of which
will need to be produced and marketed locally. Our focus on
aggregate global cereal demand does not imply that meeting
this demand would ensure global food security. Instead, our
updated projections are intended to illustrate agriculture’s
big-picture production challenge.
We build and update approximations of the FAO
(Alexandratos and Bruinsma 2012) and Tilman and col-
leagues’ (2011) projections. The FAO projected cereals
demand in 2050 directly (Alexandratos and Bruinsma 2012).
Tilman and colleagues (2011) did not, so we approximate
their projection with a simple doubling of demand from a
2005 baseline. We also linearly transform both estimates
to account for differences between the original projections’
assumed 2050 population and the latest United Nations
analysis (UN 2015). We use the most recent FAOSTAT data
(FAO 2016), from 2014, as the baseline for our projections.
All data and projections are available in the supplemental
materials.
Our updates to the FAO (Alexandratos and Bruinsma
2012) and Tilman and colleagues’ (2011) projections indi-
cate that production of cereals must only increase 26% and
68% from 2014 levels, respectively, to meet 2050 demand
(figure1a, table S1). Rapid production growth in recent years
has made substantial progress toward the original projected
increases of 46% and 100%. Cereal production increased
24% from 2005 to 2014 because of both yield improvements
and the expansion of cropped area (supplemental tables
S1 and S5; FAO 2016). The production of oilcrops—which
account for most of the remaining calories and protein from
human-edible crops—increased even more, by 39% (supple-
mental tables S2 and S4; FAO 2016). Projected 2050 demand
for oilcrops is 46% higher than 2014 production levels based
on the FAO projection and 50% higher based on a doubling
from 2005 (table S2).
The discrepancy between the two cereal demand
projections—26% versus 68%—is largely due to differ-
ences in model assumptions. The FAO (Alexandratos and
Bruinsma 2012) assumed a lower rate of annual GDP growth
than Tilman and colleagues (2011): 2.1% as compared with
2.5%. The FAO also adjusted its projection to account for
potential saturation of meat consumption in the largest
developing country, China, and cultural factors limiting the
growth of meat consumption in the second largest, India
(Alexandratos and Bruinsma 2012).
The two projections have drastically different implica-
tions for the future of crop production. Under the FAO
projection, the rate of average annual cereal yield growth
could fall gradually over the next 35 years and still meet
demand using only existing cropland. To double from a
2005 baseline, in contrast, cereal yields would have to grow
continually at a compound annual rate of over 1.5%, which
has not been achieved consistently since the mid-1980s
(figure2). Doubling yields by 2050 from a recent baseline—
the increase implied when authors do not specify the base
year for doubling—would require an even higher annual
yield growth rate of 1.9% per year.
Figure 2. Decrease in world cereal yield growth rate
over time. To double by 2050 from a 2005 baseline, yield
growth would have to be maintained at 1.5% per year.
Doubling from a 2014 baseline would require yield growth
of 1.9% per year. Each point represents the compound
annual growth rate of global average cereal yields over
the 5 previous years (FAO 2016). To smooth interannual
variation, growth rates were calculated using 5-year
moving average cereal yields.
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Sustaining these rates of average annual yield growth
until 2050, if it is even possible, would require widespread
intensification of fertilizer, pesticide, and irrigation regimes.
This level of intensification would almost certainly increase
agriculture’s impact on water quality, aquifers, wildlife, and
the climate (Robertson and Swinton 2005, Foley etal. 2011,
West et al. 2014). SI production goals should therefore be
stated carefully to avoid furthering a production-at-all-costs
approach to agriculture. Goals should reflect the updated
projection that production must increase approximately
25%–70% from recent levels to meet demand in 2050. Calls
for doubling current production by 2050 should be avoided.
Environmental goals
In contrast to the literature on food demand, there has been
little discussion of specific environmental goals for agricul-
ture in 2050 or of the sector’s trajectory toward such goals.
Instead, the prevailing discourse often focuses on increasing
efficiency or improving general “sustainability,” which gives
the impression that marginal environmental improvements
are sufficient (Petersen and Snapp 2015). To illustrate the
true scope of agriculture’s environmental challenges, we
analyze the sector’s performance against quantitative targets
that have been proposed to achieve specific environmental
outcomes: mitigating climate change and limiting eutrophi-
cation in the Gulf of Mexico.
Agricultural production activities directly contribute
11%–13% of the world’s total anthropogenic greenhouse
gas (GHG) emissions (IPCC 2014). Indirect emissions
from land-use change in agriculture and forestry contribute
another 12% (IPCC 2014). To avoid the worst impacts of
climate change, Foley and colleagues (2011) called for an
80% reduction in agricultural GHG emissions. Since direct
agricultural GHG emissions have been steadily climbing,
achieving this level of reduction by 2050 would require an
abrupt shift in emissions trajectory (figure 1b, table S3).
Losses of agricultural nutrients to waterways contribute
to hypoxic “dead zones” downstream, threatening marine
life and fisheries in coastal regions throughout the world.
The hypoxic zone in the northern Gulf of Mexico is fed
by the Mississippi–Atchafalaya River Basin system in the
central United States, where riverine nitrogen (N) and
phosphorus (P) are primarily from agricultural sources. The
second largest in the world, this dead zone reached 22,000
square kilometers (km2) in 2002 and averages 13,650 km2
per year (EPA 2016). In 2001, an intergovernmental task
force set a goal to reduce the average size of the dead zone
to 5000 km2 by 2015, which would require reducing annual
N and P loading to a level 45% below the 1980–1996 aver-
age (MRGMWNTF 2001, 2008). This goal was not met,
and the task force recently extended the deadline to 2035
(MRGMWNTF 2015). As figure 1c shows, P loading has
been increasing, and meeting the 45% reduction goal would
require a significant shift in trajectory (see also table S3). We
illustrate this goal using P data because the trends for total
N and reactive N are diverging and the Gulf Hypoxia Task
Force goal applies only to total N. Because total N has been
declining more rapidly than reactive N, using total N would
indicate greater progress toward the goal than has actually
been made.
These two examples show that agriculture still faces large
environmental challenges, but they are not meant to imply
that the sector has not made any progress. Indeed, US agri-
culture has improved in important areas, including by cut-
ting sheet, rill, and wind erosion by 43% between 1982 and
2007 (USDA 2011) and by beginning to reduce N losses in
the Midwest (McIsaac etal. 2016). However, both US and
global data on concerns ranging from biodiversity loss and
land conversion to irrigation-water withdrawals—in addi-
tion to GHG emissions and nutrient pollution—indicate that
agriculture leaves a large and growing footprint (Foley etal.
2011, West et al. 2014, Haacker et al. 2015). Clearly, envi-
ronmental sustainability cannot play second fiddle to inten-
sification; efforts to increase food production and reduce
aggregate environmental impacts must go hand in hand.
Agriculture’s path to 2050
Meeting food demand while maintaining functioning eco-
systems will require a recalibrated SI strategy, in which
up-to-date production goals are coupled with quantitative
environmental targets. Research and policy should pivot to
align with this strategy, both in the United States and glob-
ally. Here, we focus on the US context.
The research enterprise led by the National Science
Foundation and the US Department of Agriculture (USDA)
should prioritize efforts to identify and meet quantita-
tive production and environmental goals. First, research is
needed to specify targets in both categories. There is a par-
ticularly urgent need to quantify the reductions in pollution
and land degradation that must be achieved to sustain func-
tioning ecosystems at multiple scales (Neufeldt etal. 2013,
Rockström etal. 2017). These goals will need to be refined
periodically as new information becomes available, given the
uncertainty of long-term projections.
Second, applied agricultural research should focus on
developing production systems that can simultaneously
meet both production and environmental targets while help-
ing farmers adapt to a range of emerging challenges, such as
mounting water shortages (Falkenmark 2013, Elliott et al.
2014), pesticide resistance (Mortensen etal. 2012), yield pla-
teaus (Grassini etal. 2013, Ray etal. 2013), and the changing
climate (Challinor etal. 2014). The technical challenge of
such a fundamental transformation in production systems is
daunting, and meeting both sets of goals will require navi-
gating complex trade-offs (Robertson and Swinton 2005,
Neufeldt etal. 2013, Davis etal. 2016). However, establishing
clear targets will help researchers focus on these long-term
challenges.
Achieving both production and environmental goals will
require shifts in US agricultural policy. Current policy heav-
ily favors production, including through crop insurance and
revenue- and price-based subsidy payments for commodity
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390 BioScience •April 2017 / Vol. 67 No. 4 http://bioscience.oxfordjournals.org
crops. These programs carry only minimal environmental
requirements, which provide limited protection against
erosion and the loss of some wetlands and grasslands, but
fail to target nutrient loss, air quality, GHG emissions, and
other concerns. Conservation incentive programs help pro-
ducers implement many environmentally beneficial prac-
tices, but they are not structured to produce maximum
benefits. Moreover, many environmental regulations cur-
rently exempt agricultural activities. To bring US policy
in line with future needs, producers who receive subsidies
should be required to meet more stringent environmental
standards, conservation programs should be reformed to
tie payments to quantified outcomes (Winsten and Hunter
2011), and effective regulatory backstops should be insti-
tuted to control the most environmentally damaging prac-
tices. Quantitative targets can help guide these policy efforts
and promote effective collaborations among researchers,
farmers, government agencies, and civil-society groups.
The Danish government’s pesticide strategy, which aims to
reduce pesticide loads by 40%, is one promising example of
using quantitative targets to collaboratively set agroenviron-
mental policy (DME 2013).
The goals of sustainable intensification extend beyond
aggregate production and environmental performance.
Additional policy efforts are needed to manage food demand
by reducing food waste (West etal. 2014) and shifting diets
(Davis et al. 2016). We must also halt cropland expan-
sion (Cunningham etal. 2013) and ensure that the world’s
poorest people have secure access to nutritious food (FAO
et al. 2015). Total land in agriculture has risen since 2005
in Africa, South America, and Asia (supplemental table S6;
FAO 2016), indicating continued land conversion at the
expense of native ecosystems, and conversion continues in
the United States as well (Lark et al. 2015). Approximately
795 million people are hungry today, despite adequate global
food production, because poverty, lack of infrastructure,
poor governance, natural disasters, and political unrest
restrict food access (FAO etal. 2015). These problems must
be addressed even as production increases and pollution
plummets.
Conclusions
We call on researchers, policymakers, and farmers to
embrace this recalibrated vision of sustainable intensifica-
tion. Time is short: The annual cycle of planting and harvest
gives farmers fewer than 35 chances to transform their pro-
duction systems by midcentury. Scientists also face a limited
number of opportunities to develop and test new production
and conservation strategies. As a group of young agricultural
scientists (and one senior scientist), this is the challenge of
our careers. By the time our generation retires, agriculture’s
2050 goals must be met.
Acknowledgments
We thank Armen Kemanian, Nicholas Jordan, Adam Davis,
and the three anonymous reviewers for suggestions that
improved the manuscript and Emily Pia for assistance with
the analysis. This material is based on work supported by the
National Science Foundation under grant no. DGE1255832.
Any opinions, findings, and conclusions or recommenda-
tions expressed in this material are those of the authors and
do not necessarily reflect the views of the National Science
Foundation. This project was also supported by USDA
Agriculture and Food Research Initiative Climate Change
Mitigation and Adaptation in Agriculture grant no. 2011-
67003-30343 and USDA Organic Research and Extension
Initiative grant no. 2011-51300-30638.
Supplemental material
Supplementary data are available at BIOSCI online.
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Mitchell C. Hunter (mchunter@psu.edu) is a PhD candidate and David
A. Mortensen is a professor in the Plant Science Department and Ecology
Intercollege Graduate Degree Program at The Pennsylvania State University,
University Park. MCH studies the implications of cover cropping for drought
tolerance and climate resilience in maize. DAM studies the impacts of crop-
and weed-management methods on the ecological integrity of managed land-
scapes. Richard G. Smith is an associate professor and Lesley W. Atwood is a
PhD candidate in the Department of Natural Resources and the Environment
at the University of New Hampshire, in Durham. RGS studies the roles that
crop-plant diversity and species interactions play in regulating agroecosystem
functions. LWA studies the effects of agricultural management on soil faunal
diversity and function. Meagan E. Schipanski is an assistant professor in the
Department of Soil and Crop Sciences at Colorado State University, in Fort
Collins. MES studies crop diversity and nutrient dynamics in agroecosystems
at multiple scales.
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