There is a big shortfall between the amount of food we
produce today and the amount needed to feed everyone in 2050. There will be
nearly 10 billion people on Earth by 2050—about 3 billion more mouths to feed
than there were in 2010. As incomes rise, people will increasingly consume more
resource-intensive, animal-based foods. At the same time, we urgently need to
cut greenhouse gas (GHG) emissions from agricultural production and stop
conversion of remaining forests to agricultural land.
Feeding 10 billion people sustainably by 2050,
then, requires closing three gaps:
A 56 percent food gap between crop calories produced in
2010 and those needed in 2050 under “business as usual” growth;
A 593 million-hectare land gap (an area nearly twice
the size of India) between global agricultural land area in 2010 and expected
agricultural expansion by 2050; and
An 11-gigaton GHG mitigation gap between expected
agricultural emissions in 2050 and the target level needed to hold global
warming below 2oC (3.6°F), the level necessary for preventing the worst climate
impacts.
A Five-Course Menu of Solutions for a Sustainable Food
Future
There is no silver bullet to close the food, land and GHG
mitigation gaps. I have researched and identified 22 solutions that need to be
simultaneously applied to close these gaps. The relative importance of each
solution varies from country to country. The solutions are organized into a
five-course menu: (1) reduce growth in demand for food and other agricultural
products; (2) increase food production without expanding agricultural land; (3)
protect and restore natural ecosystems; (4) increase fish supply; and (5)
reduce GHG emissions from agricultural production.
First Course: Reduce Growth In Demand for Food and
Other Agricultural Products
1.
Reduce food loss and waste.
Approximately one-quarter of food produced for human
consumption goes uneaten. Loss and waste occurs all along the food chain, from
field to fork. Reducing food loss and waste by 25 percent by 2050 would close
the food gap by 12 percent, the land gap by 27 percent and the GHG mitigation
gap by 15 percent. Actions to take include measuring food waste, setting
reduction targets, improving food storage in developing countries and
streamlining expiration labels.
2. Shift to healthier, more sustainable diets.
Consumption of ruminant meat (beef, lamb and goat) is
projected to rise 88 percent between 2010 and 2050. Beef, the most commonly
consumed ruminant meat, is resource-intensive to produce, requiring 20 times
more land and emitting 20 times more GHGs per gram of edible protein than
common plant proteins, such as beans, peas and lentils. Limiting ruminant meat
consumption to 52 calories per person per day by 2050—about 1.5 hamburgers per
week—would reduce the GHG mitigation gap by half and nearly close the land gap.
In North America this would require reducing current beef and lamb consumption
by nearly half. Actions to take include improving the marketing of plant-based
foods, improving meat substitutes and implementing policies that favor
consumption of plant-based foods.
3. Avoid competition from bioenergy for food crops and
land.
If bioenergy competes with food production by using food or
energy crops or dedicated land, it widens the food, land and GHG mitigation
gaps. Biomass is also an inefficient energy source: Using all the harvested
biomass on Earth in the year 2000—including crops, crop residues, grass eaten
by livestock and wood—would only provide about 20 percent of global energy
needs in 2050. Phasing out existing biofuel production on agricultural lands
would reduce the food gap from 56 to 49 percent. Actions to take include
eliminating biofuel subsidies and not treating bioenergy as “carbon-neutral” in
renewable energy policies and GHG trading programs.
4. Achieve replacement-level fertility rates.
The food gap is mostly driven by population growth, of which
half is expected to occur in Africa, and one third in Asia. Most of the world
is close to achieving replacement-level fertility by 2050 (2.1 children per
woman). Sub-Saharan Africa is the exception, with a current fertility rate
above 5 children per woman and a projected rate of 3.2 in 2050. If sub-Saharan
Africa achieved replacement-level fertility rates along with all other regions
by 2050, it would close the land gap by one quarter and the GHG mitigation gap
by 17 percent while reducing hunger. Actions to take include achieving the
three forms of social progress that have led all others to voluntarily reduce
fertility rates: increasing educational opportunities for girls, expanding
access to reproductive health services, and reducing infant and child mortality
so that parents do not need to have as many children to ensure survival of
their desired number.
Course 2: Increase Food Production Without Expanding
Agricultural Land
5. Increase livestock and pasture productivity.
Livestock production per hectare varies significantly from
country to country and is lowest in the tropics. Given that demand for
animal-based foods is projected to grow by 70 percent by 2050 and that
pastureland accounts for two thirds of agricultural land use, boosting pasture
productivity is an important solution. A 25 percent faster increase in the
output of meat and milk per hectare of pasture between 2010 and 2050 could
close the land gap by 20 percent and the GHG mitigation gap by 11 percent.
Actions farmers can take include improving fertilization of pasture, feed
quality and veterinary care; raising improved animal breeds; and employing
rotational grazing. Governments can set productivity targets and support
farmers with financial and technical assistance.
6. Improve crop breeding.
Future yield growth is essential to keep up with demand.
Conventional breeding, the selection of best-performing crops based on genetic
traits, accounted for around half of historical crop yield gains. New advances
in molecular biology offer great promise for additional yield gains by making
it cheaper and faster to map genetic codes of plants, test for desired DNA
traits, purify crop strains, and turn genes on and off. Actions to take include
significantly increasing public and private crop-breeding budgets, especially
for “orphan crops” like millet and yam, which are regionally important, but not
traded globally.
7. Improve soil and water management.
Degraded soils, especially in Africa’s drylands, may affect
one quarter of the world’s cropland. Farmers can boost crop yields in degraded
soils—particularly drylands and areas with low carbon—by improving soil and
water management practices. For example, agroforestry, or incorporating trees
on farms and pastures, can help regenerate degraded land and boost yields.
Trial sites in Zambia integrating Faidherbia albida trees yielded
88–190 percent more maize than sites without trees. A 20 percent faster increase
in crop yields between 2010 and 2050—as a result of improvements in crop
breeding and soil and water management—could close the land gap by 16 percent
and the GHG mitigation gap by 7 percent. Actions to take include increasing aid
agencies’ support for rainwater harvesting, agroforestry and farmer-to-farmer
education; and reforming tree-ownership laws that impede farmers’ adoption of
agroforestry. Agencies can also experiment with programs that help farmers
rebuild soil health.
8. Plant existing cropland more frequently.
Planting and harvesting existing croplands more frequently,
either by reducing fallow land or by increasing “double cropping” (planting two
crops in a field in the same year), can boost food production without requiring
new land. Increasing annual cropping intensity by 5 percent beyond the 2050
baseline of 87 percent would shrink the land gap by 14 percent and the GHG
mitigation gap by 6 percent. Researchers should conduct more spatially explicit
analyses to determine where cropping intensity increases are most feasible,
factoring in water, emissions and other environmental constraints.
9. Adapt to climate change.
The 2014 Intergovernmental Panel on Climate Change report
projected that without adaptation, global crop yields will likely decline by at
least 5 percent by 2050, with steeper declines by 2100. For example, growing
seasons in much of sub-Saharan Africa are projected to be more than 20 percent
shorter by 2100. A 10 percent decline in crop yields would increase the land
gap by 45 percent. Adaptation will require implementing other menu items, as
well as breeding crops to cope with higher temperatures, establishing water
conservation systems, and changing production systems where major climate
changes will make it impossible to grow certain crops.
Course 3: Protect and Restore Natural Ecosystems and
Limit Agricultural Land-Shifting
10. Link productivity gains with protection of natural
ecosystems.
While improving agricultural productivity can save forests
and savannas globally, in some cases it can actually cause more land clearing
locally. To avoid these results, productivity gains must be explicitly
linked with efforts to protect natural ecosystems from conversion to
agriculture. Governments, financiers and others can tie low interest credit to
protection of forests, as Brazil has done, and ensure that infrastructure
investments do not come at the expense of ecosystems.
11. Limit inevitable cropland expansion to lands with
low environmental opportunity costs.
When cropland expansion is inevitable—such as for local food
production in Africa and for oil palm in Southeast Asia—governments and
investors should support expansion onto land with low environmental opportunity
costs. This includes lands with limited biodiversity or carbon storage
potential, but high food production potential. For example, analysis that
applies environmental, economic and legal filters in Indonesia can develop more
accurate estimates of land suitable for oil palm expansion. Governments need
tools and models to estimate yields and effects on biodiversity and climate
change, and they should use these tools to guide land-use regulations, plan
roads and manage public lands.
12. Reforest agricultural lands with little
intensification potential.
In some cases, the most efficient use of land may be to
restore abandoned or unproductive agricultural lands back into forests or other
natural habitats. This can help offset the inevitable expansion of agriculture
into other areas. This should be limited to low productivity agricultural land
with limited improvement potential, such as steeply sloping pastures in Brazil’s
Atlantic Forest.
13. Conserve and restore peatlands.
Peatlands’ conversion for agriculture requires drainage,
which releases large amounts of carbon into the atmosphere. The world’s 26
million hectares of drained peatlands account for 2 percent of annual
greenhouse gas emissions. Restoring them to wetlands should be a high priority
and would close the GHG mitigation gap by up to 7 percent. Actions to take
include providing funds for peatland restoration, improving peatland mapping
and establishing laws that prevent peatlands from being drained.
Course 4: Increase Fish Supply
14. Improve wild fisheries management.
One third of marine stocks were overfished in 2015, with
another 60 percent fished at maximum sustainable levels. Catches need to
be reduced today to allow wild fisheries to recover enough just to maintain the
2010 fish-catch level in 2050. This would avoid the need to convert 5 million
hectares of land to supply the equivalent amount of fish from aquaculture.
Actions to take include implementing catch shares and community-based
management systems, and removing perverse subsidies that support overfishing,
estimated at $35 billion annually.
15. Improve productivity and environmental performance
of aquaculture.
As wild fish catches decline, aquaculture production needs
to more than double to meet a projected 58 percent increase in fish consumption
between 2010 and 2050. This doubling requires improving aquaculture
productivity and addressing fish farms’ current environmental challenges,
including conversion of wetlands, use of wild-caught fish in feeds, high
freshwater demand and water pollution. Actions to take include selective
breeding to improve growth rates of fish, improving feeds and disease control,
adoption of water recirculation and other pollution controls, better spatial
planning to guide new farms and expansion of marine-based fish farms.
Course 5: Reduce Greenhouse Gas Emissions from
Agricultural Production
GHG emissions from agricultural production arise from
livestock farming, application of nitrogen fertilizers, rice cultivation and
energy use. They’re projected to rise from 7 to 9 gigatons per year or more by
2050 (in addition to 6 gigatons per year or more from land-use change, not
shown in the chart below). This course addresses each of these major emissions
sources.
16. Reduce enteric fermentation through new
technologies.
Ruminant livestock were responsible for around half of all
agricultural production emissions in 2010. Of these emissions, the largest
source is “enteric methane,” or cow burps. Increasing productivity of ruminants
also reduces methane emissions, mainly because more milk and meat is produced
per kilogram of feed. In addition, new technologies can reduce enteric
fermentation. For example, 3-nitrooxypropan (3-NOP), a chemical additive that
inhibits microbial methane, was tested in New Zealand and cut methane emissions
by 30 percent and may increase animal growth rates. Governments should expand public
research into compounds like 3-NOP and require or incentivize adoption of the
most promising.
17. Reduce emissions through improved manure
management.
Emissions from “managed” manure, originating from animals
raised in confined settings, represented around 9 percent of agricultural
production emissions in 2010. Improving manure management by better separating
liquids from solids, capturing methane, and other strategies can greatly reduce
emissions. For example, using highly sophisticated systems to reduce virtually
all forms of pollution from U.S. pig farms would only increase the price of
pork by 2 percent while reducing GHGs and creating many health, water and
pollution benefits. Measures governments can take include regulating farms,
providing competitive funding for technology development, and establishing
monitoring programs to detect and remediate leakages from digesters.
18. Reduce emissions from manure left on pasture.
Livestock feces and urine deposited in fields turns into
nitrous oxide, a potent greenhouse gas. This unmanaged manure accounted for 12
percent of agricultural production emissions in 2010. Emerging approaches
involve applying chemicals that prevent nitrogen from turning into nitrous
oxide, and growing grasses that prevent this process naturally. Governments can
increase support for research into such chemical and biological nitrification
inhibitors and incentivize adoption by farmers.
19. Reduce emissions from fertilizers by increasing
nitrogen use efficiency.
Emissions from fertilizers accounted for around 19 percent
of agricultural production emissions in 2010. Globally, crops absorb less than
half the nitrogen applied as fertilizer, with the rest emitted to the
atmosphere or lost as run off. Increasing nitrogen use efficiency, the
percentage of applied nitrogen absorbed by crops, involves improving
fertilizers and their management—or the composition of the fertilizers
themselves—to increase the rate of nitrogen uptake, thus reducing the amount of
fertilizer needed. Actions governments can take include shifting subsidies from
fertilizers to support higher nitrogen use efficiency, implementing regulatory
targets for fertilizer companies to develop improved fertilizers, and funding
demonstration projects that increase nitrogen use efficiency.
20. Adopt emissions-reducing rice management and
varieties.
Rice paddies contributed at least 10 percent of agricultural
production emissions in 2010, primarily in the form of methane. But there are
less emissions- and resource-intensive rice production methods. For example,
shortening the duration of field flooding can reduce water levels to decrease
the growth of methane-producing bacteria. This practice can reduce emissions by
up to 90 percent while saving water and increasing rice yields on some farms.
Some rice varieties also generate less methane. Actions to take include
conducting engineering analyses to identify promising opportunities for
reducing water levels, rewarding farmers who practice water-efficient farming,
investing in breeding programs that shift to lower-methane rice varieties and
boosting rice yields.
21. Increase agricultural energy efficiency and shift
to non-fossil energy sources.
Emissions from fossil energy use in agriculture accounted
for 24 percent of agricultural production emissions in 2010. The basic
opportunities include increasing energy efficiency, which has been only
modestly explored in agricultural settings, and switching to solar and wind.
Reducing emissions per unit of energy used by 75 percent would reduce the GHG mitigation
gap by 8 percent. Actions to take include integrating low-carbon energy sources
and efficiency programs into agriculture programs and using renewable energy in
nitrogen fertilizer manufacturing.
22. Implement realistic options to sequester carbon in
soils.
Efforts to mitigate agricultural emissions have primarily
focused on sequestering carbon in soils, but recent research suggests this is
harder to achieve than previously thought. For example, practices to increase
carbon, such as no-till farming, produced little or no carbon increases when
measured at deeper soil depths. Important strategies include avoiding further
loss of carbon from soils by halting conversion of forests, protecting or
increasing soil carbon by boosting productivity of grasslands and croplands,
increasing agroforestry, and developing innovative strategies for building
carbon where soil fertility is critical for food security.
Moving Toward a Sustainable Food Future
The challenge of feeding 10 billion people sustainably by
2050 is much harder than people realize. These menu items are not optional—the
world must implement all 22 of them to close the food, land and GHG mitigation
gaps.
The good news is that all five courses can close
the gaps, while delivering co-benefits for farmers, society and human health.
It will require a herculean effort and major changes to how we produce and
consume food. So, let’s get started and order everything on the menu!
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