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8
June
2023
WUSF Public Media - WUSF 89.7
By
Josie
Heimsoth - University of Missouri
The price of plenty: Fertilizer’s greenhouse gas
emissions add up
Phosphates And Florida
Phosphate processing plants in the greater Tampa Bay region have
caused some of Florida's worst environmental disasters. Accidents like
the spill at the former Piney Point plant fill the history books in
Florida.
Josie Heimsoth/Missourian
In southeastern Louisiana, CF Industries’ Donaldsonville complex sits
along the west bank of the Mississippi River. It is the world’s
largest ammonia production facility and produces 8 million tons of
nitrogen products each year.
From the factory to the field, fertilizer is a
significant source of heat-trapping gases. Can the industry lessen its
footprint?
A complex of industrial towers rises from the flat landscape at the
edge of a highway here, its stacks and pipes snaking around each
other. Workers in neon yellow vests and protective helmets navigate
the maze in pickups while an industrial hum blankets the area.
Manufactured clouds float above the nearby Mississippi River, where
barges and ships move goods up- and downstream.
This is CF Industries’ Donaldsonville Complex, the world’s largest
ammonia production facility. The 1,400-acre nitrogen fertilizer plant
is part of a sprawling global industry that’s responsible for a
significant chunk of greenhouse gas emissions worldwide. According to
a 2022 study in Scientific Reports, the synthetic nitrogen fertilizer
supply chain is responsible for 2.1% of global heat-trapping gas
emissions – greater than the emissions from all aviation.
The Donaldsonville plant alone is the largest
source of industrial greenhouse gas emissions in Louisiana. But the
emissions footprint of nitrogen fertilizers doesn’t stop at the
factory; planet-warming gases arise throughout the fertilizer’s life
cycle.
According to the study, only about 41% of emissions come from the
process of making and shipping fertilizer from industrial facilities
like the one here. The majority come from emissions generated from
farm fields after the fertilizer is spread.
The root of the problem: Some farmers are applying more fertilizer
than what is needed for optimal plant growth. “The plants are not
taking the extra nitrogen,” said Alicia Ledo, a freelance scientist
and co-author of the Scientific Reports study. “It’s just going up
into the atmosphere, which is a waste.”
The journey of nitrogen fertilizer – and its release of potent
heat-trapping gases – is an extensive one, and it affects the climate
along the way.
The greenhouse gases from the lifecycle of fertilizer consist of
emissions from fertilizer production, transportation and use.
Starting at the factory
The discovery of a process to make synthetic fertilizer in the early
20th Century revolutionized agriculture, enabling great leaps in
productivity. The Haber-Bosch process, still in use today, takes
nitrogen from the air and combines it with hydrogen from fossil fuel –
usually natural gas, also called methane – to produce ammonia. The
process emits two main greenhouse gases: methane and carbon dioxide.
Ammonia is a feedstock in producing nitrogen-based fertilizers like
urea. It is also the world’s second most-produced chemical, accounting
for 2%
of worldwide fossil fuel energy use. As a result, the chemical
generates 450 million tons of carbon dioxide annually and is more
emissions-intensive than steel and cement making.
In 2019, CF Industries’ Donaldsonville Complex reported more than 10
million metric tons of carbon dioxide emissions – equal to the
annual emissions from 2.7
coal-fired power plants.
The manufacturing process also releases methane, a gas more than 25
times as potent as carbon dioxide that lasts a shorter time in the
atmosphere. A study by
Cornell University and the Environmental Defense Fund found methane
emissions from six representative fertilizer ammonia plants were 100
times higher than the fertilizer industry’s self-reported estimates.
On to farm fields in the Midwest and elsewhere
After production, fertilizer is shipped out via pipelines, barges,
ships, trains and trucks. Transportation accounts for 2.6% of
fertilizer’s total emissions, according to the study.
Then it’s on to distributors and ultimately, farmers and their fields.
Every year, 6
million tons of nitrogen fertilizer are applied to corn across the
U.S. Much goes to the nation’s Corn Belt, nearly 1,500 miles of
Midwestern landscape dominated by this nitrogen-needy crop.
In the United States, an estimated 72
million tons of carbon dioxide-equivalent emissions come from the
nitrogen applied on farmers’ fields.
It’s all about the nitrogen cycle, a series of processes where
nitrogen and its compounds are made accessible to plants and other
living organisms. The air we breathe is full of nitrogen, but plants
need to convert the gas into a usable form. Bacteria and other
organisms help break it down.
Some crops are good at fixing nitrogen, like legumes, beans and peas.
But nitrogen-guzzling crops such as corn, tomatoes and melons often
cannot meet their nitrogen needs without extra help.
Synthetic fertilizer adds a shot of pure nitrogen to the soil – but
not all of it gets used by plants. Some of it is lost to the air
during application, and some is lost as microbes fix nitrogen in the
soil and later release it again to the atmosphere. Fertilizer gooses
the soil’s natural microbial activities to produce more nitrous oxide,
a gas 265
times more potent than carbon dioxide. This gas consumes the ozone
layer, which shields earth from the sun’s ultraviolet radiation.
Maya Morris/Missourian/University Of California,
Agriculture And Natural Resources Nitrogen fertilizer has tipped the
soil's nitrogen cycle out of balance.
Nitrous oxide emissions are produced “to some extent anytime nitrogen
is available in the soil,” said Rod Venterea, a soil scientist at USDA
and adjunct professor at the University of Minnesota. “That’s been
going on for thousands of years. Now, we have the opportunity to add
larger amounts of nitrogen to the soil, and that’s stimulating natural
processes, as well as creating hot spots of production well beyond
what is produced naturally.”
Emptying into streams and rivers
Extra fertilizer also can wash off fields and into groundwater and
rivers, sending nitrogen, phosphorus and other nutrients downstream.
High levels of nutrients causes algae to grow in bodies of water, in
turn creating more emissions of nitrous oxide, carbon dioxide and
methane. This process is called eutrophication.
A 2018 study estimated
that emissions from eutrophication in lakes and impoundments are equal
to about 20% of global carbon dioxide emissions from fossil fuels.
Global methane emissions from eutrophication in the world’s lakes are
expected to increase
30-90% over the next century due to climate change and population
growth.
Jessica D’Ambrosio, Ohio agriculture project director of the Nature
Conservancy, works to reduce nutrient pollution into Lake Erie, which
has suffered from extensive algae blooms caused in part by fertilizer
runoff. Roughly 80% of the land draining into the lake is
agricultural.
“If you reduce the amount of nitrogen fertilizer you use, you’re
helping reduce algal blooms and greenhouse gas emissions,” D’Ambrosio
said. “If your soils are healthy and they’re holding on to nutrients,
it’s doing both things for you and your watershed.”
Lowering fertilizer’s greenhouse gas emissions
Given fertilizer’s huge greenhouse gas footprint, producers and users
are facing increasing pressure to change.
Earlier this year, André Cabrera Serrenho, an assistant professor of
engineering at the University of Cambridge, co-authored a study
in Nature Food that found the emissions from fertilizers could be
reduced by 80% by 2050 using currently available technologies.
Serrenho’s study estimated that about a third of fertilizer emissions
could be reduced by decarbonizing in the production process. Renewable
energy can be used for heating and creating the hydrogen used to make
ammonia. This process is sometimes called “green hydrogen” production.
Another option is using so-called “blue ammonia,” which still relies
on fossil fuels but captures and stores the resulting carbon dioxide,
sometimes injecting it underground to help
recover oil and gas.
Lauren Whiddon/WUFT In Florida’s “Bone Valley,” a
hotspot for fertilizer production, a pipeline transports liquid
ammonia.
The fertilizer industry has latched onto both
technologies. For example, CF Industries’ Donaldsonville plant began
construction on an electrolysis system at the end of 2021 that is
expected to produce 20,000 tons of green ammonia a year, or a quarter
of 1% of its total production. The company also has partnered with
ExxonMobil on a project to capture and sequester about 20% of the CO2
produced at its Donaldsonville Complex, and last year the company
announced it was evaluating a site in Ascension Parish for
construction of a new $2 billion, export-oriented blue ammonia
production facility.
The Mosaic Co., another leading fertilizer company, is working to
achieve net-zero emissions by 2030 in Florida, where it’s
headquartered, and throughout its operations by 2040. Mosaic is not
pursuing green ammonia at this time due to the high cost and is
exploring carbon capture, spokeswoman Natali Archibee said.
Carbon capture technologies have been met with controversy from
residents who don’t want more industrial facilities in their
backyards, and from critics who say it only maintains reliance on
fossil fuels.
A 2022 report by the Center for International Environmental Law called
carbon capture technology a “false solution” that attempts to launder
the fertilizer industry’s emissions through “greenwashed” products.
“The energy required to produce blue hydrogen makes it as bad, if not
worse, than just burning gas directly,” said Carroll Muffett,
president and CEO of CIEL.
Serrenho said that greener production is only part of the solution
because most emissions come from soil. “Even if the petrochemical
industry is amazing at decarbonizing their own productions, that only
reduces one-third of the total emissions,” he said. “The other two
thirds need to be tackled.”
Nitrous oxide emissions from bacteria in the soil can be reduced by
adding chemicals called nitrification inhibitors, his study found.
Switching to lower-emission fertilizers also would help.
However, the most important change is to cut the amount of fertilizer
used. Less than half of fertilizer applied globally is taken up by
plants. Farmers could use far less without reducing yield. “Just by
doing that we can save half of emissions associated with fertilizers
and other environmental impacts,” Serrenho said.
The CIEL report called for a transition away from industrial
agricultural models and synthetic fertilizer and toward more
regenerative models that would make food more sustainable to produce
while protecting biodiversity.
“Beginning that transition away from fossil fertilizers to more
sustainable food solutions is not only a critical part of responding
to the climate crisis, but also putting us back within our planetary
boundaries that keep the Earth safe to live on,” Muffett said.
This story is part of The Price of Plenty, a special project
investigating fertilizer from the University of Florida College of
Journalism and Communications and the University of Missouri School of
Journalism, supported by the Pulitzer Center’s nationwide Connected
Coastlines reporting initiative.
Green Play Ammonia™, Yielder® NFuel Energy.
Spokane, Washington. 99212
509 995 1879 Cell,
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General office: 509-254
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4501 East Trent Ave.
Spokane, WA 99212
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