There has certainly been a lot of debate about the safety of glyphosate, especially since the World Health Organization’s International Agency for Research on Cancer (IARC) classified it in 2015 as a “probable human carcinogen,” A new paper published in GM Crops & Food, analyzes the CO2 equivalent emissions reductions that arise from the manufacture, distribution and farm level use of glyphosate as a vital part of conservation tilling, which refers to reduced-till or no-till farming. The paper attempts to quantify the emissions. According to the abstract, those emissions reductions are massive:
“Conservation tillage practices provide a net reduction
in combined annual fuel and increased soil carbon retention-related emissions
of −179.67 billion kg CO2e relative to a conventional plow-based alternative
production system.”
Glyphosate is typically used
to control weeds in preparing land before crops are planted. It is also applied
between crop rows and around the perimeters of the crops.
The paper’s analysis includes
an extensive literature review. Methodologies include the quantification of
global glyphosate use, calculation of emissions from glyphosate manufacture,
distribution, and farm-level use, calculation of emissions reduction from the
use of conservation tillage, calculation of the
contribution of glyphosate to emissions reduction from the use of conservation
tillage, and comparisons to conventional crops and genetically modified
herbicide-tolerant (GM HT) crops. The paper explains some of the aims of the
literature review:
“A primary aim of the literature review was to identify
the evidence about emissions after adoption of conservation tillage practices,
soil organic carbon levels and other possible emissions such as nitrous oxide
(N2O) relative to conventional tillage practices.”
The literature review
explored duration of studies, depth of soil carbon measurements, soil types,
latitude and climate differences, interaction of conservation tillage with
other conservation management practices, continuity of conservation tillage,
and the combined effect of temperature, moisture, and soil texture on soil
carbon.
Table 1 shows the different
tillage practices and how they are defined. These include conventional tillage
(CT), reduced tillage (RT), and no tillage (NT. In addition, mulching and crop
rotations are typically used in CT and RT. CT and RT make up conservation
tillage (COT).
Table 2 quantifies fuel use
for CT, RT, and NT.
Table 3 shows glyphosate use
by country, and that the U.S. and Brazil, two of the world’s agricultural
powerhouses, use the most glyphosate.
Table 4 shows the annual
average glyphosate use for 2019–2022 by crop/use.
Table 5 shows the annual
average CO2e emissions from the manufacture and distribution of glyphosate used
in global agriculture by country of use: baseline 8.39 billion kg.
Tables 6 and 7 show
comparisons of RT and NT with CT in terms of fuel use and soil carbon
retention.
Table 8 notes glyphosate use
in stages of crop growth key to the adoption of conservation tillage for
2019-2022, and Table 9 breaks that information down by country.
Table 10 compares NT/RT-based
conservation tillage area compared to levels if the same area was tilled by
plough, attributable to glyphosate, by country.
Table 11 compares annual
global soil carbon retention CO2e emissions for NT-based conservation tillage
area compared to levels if the same area was tilled by plough, attributable to
glyphosate, by country.
Table 12 is a summary of
global annual CO2e emissions/storage attributable to the use of glyphosate in
agriculture: 2019–2022 annual average.
The paper goes on to describe applying
sensitivity analysis to arrive at the final estimates.
The Environmental Benefits of Glyphosate
Dan Blaustein-Rejto, writing
for the Ecomodernist, explores the environmental benefits of glyphosate. He
recounts public opposition to glyphosate due to perceived health impacts, soil
health impacts, pollinator impacts, water contamination, and degradation of
biodiversity. He argues that the net impacts of glyphosate are beneficial due
to it replacing other, more toxic herbicides and “enabling farming practices
that reduce soil erosion, water and air pollution, energy use, and crop losses.”
He explains that glyphosate
is mostly used for animal feed, biofuel, and fiber instead of human
consumption:
“Glyphosate was first approved and marketed in the
United States in 1974 as a broad-spectrum herbicide designed to kill most
plants it contacts. Its rise coincided with the commercialization of
genetically engineered glyphosate-tolerant (“Roundup Ready”) crops beginning in
the mid-1990s. Today, glyphosate is primarily used on corn, soybean, and cotton
operations, applied to roughly 80–90% of those crops’ acreages. These
crops—which are overwhelmingly grown for animal feed, biofuel, and fiber rather
than direct human consumption—account for the vast majority of all agricultural
glyphosate usage, about 84%.”
He emphasizes glyphosate’s
low toxicity compared to other herbicides:
“By almost any measure, glyphosate and glyphosate-based
herbicides (which contain other substances such as surfactants) have a low
toxicity even at the high volumes used.”
He also notes that glyphosate
is not environmentally harmless:
“Ecological risk assessments from EPA and other
regulatory agencies identify real concerns in some contexts. Chronic glyphosate
exposure may slow growth of some birds. But one of the most concrete risks is
not from glyphosate itself, but from surfactants that are mixed into some
formulations to help it better penetrate plant leaves: EPA finds that drift
from heavy aerial application of formulations with polyethoxylated tallow amine
(POEA) carry a slight risk to some freshwater fish, amphibians, and aquatic invertebrates.
Likewise, some formulations may increase the impact of acute exposure to birds,
though the evidence on this is limited.”
The graph below compares glyphosate to other herbicides.
As the paper explored above
notes, one of glyphosate’s most important environmental benefits is in
herbicide-enabled no-till farming. He notes that once glyphosate-tolerant (GT)
crops were developed, conservation tillage was enabled to grow successfully.
Avoiding tillage has several other benefits, such as less fuel use, reducing
soil erosion, soil moisture retention, preservation of soil structure, and much
more.
“Though often overlooked, conservation tillage also
reduces the amount of dirt and dust from farming, significantly improving air
quality.”
One practice that has been
particularly vilified is the pre-harvest spraying of glyphosate on wheat and
some legumes. RFK Jr. and other MAHA advocates have recommended banning this
practice. Blaustein-Rejto points out that this practice is uncommon, considered
safe, and has unique environmental benefits. The practice is rare, being used
on only about 3% of wheat. Measured residues were still small for these crops.
“Even in an implausibly extreme scenario where a child
ate only wheat products made from grain that was sprayed pre-harvest and had
the maximum legal glyphosate residues persist on it through processing, they
would need to eat more than 1 ½ loaves of bread or 15 cups of pasta per day to
reach EPA’s daily safety limit. That threshold is itself quite conservative,
set 100 times below the highest dose that caused no harm in relevant animal
studies.”
Pre-harvest spraying can keep
weeds down for subsequent crops, help spare land, and increase yields.
“Grain dryers burn large amounts of propane or natural
gas to reduce moisture levels. Finally, when compared to other chemical
desiccants, glyphosate is often one of the lowest-impact options available.”
Glyphosate is certainly not
the perfect herbicide, but it is much more beneficial than other herbicides,
including some organic ones. Even better alternatives should continue to be
pursued.
He also touts new
technologies:
“Precision application technologies that use computer
vision and machine learning to identify and spray individual weeds can reduce
herbicide use by about 30–60%, and up to 90 percent in some cropping systems
and studies. Autonomous robotic weeders are beginning to scale beyond specialty
crops and into row-crop agriculture. Recent proposals in Congress to increase
support for farmers to purchase precision agriculture equipment could go a long
way to accelerating adoption. But development of new pesticides, both synthetic
and biological, as well as herbicide-tolerant genetically engineered crops
remains critical for farmers to better manage weeds, especially ones that are
resistant to existing herbicides.”
Regulatory support for
residue analysis is also important:
“USDA and FDA should expand routine monitoring for
glyphosate and other herbicide residues and report results clearly. This is not
because more evidence would necessarily identify new risks, but rather because
public trust depends on visibility and accountability.”
Finally, he summarizes the
benefits of glyphosate:
“Glyphosate illustrates the environmental promise and
tradeoffs of agricultural innovation. It helped enable meaningful reductions in
tillage, fuel use, and herbicide toxicity. It also carries ecological risks
that warrant continued research, scrutiny, and management. For policymakers,
the key question is not whether glyphosate is flawless, but rather how to
encourage its responsible use and develop alternatives that deliver better
environmental outcomes. That requires rigorous oversight, transparent monitoring,
and federal support for innovation instead of bans that replace one set of
impacts with more damaging ones.”
Trump Executive Order Calls Glyphosate “Central to American
Economic and National Security” and Calls for Adequate Supply
In a break from RFK Jr. and
anti-GMO activists, an executive order was announced that calls glyphosate
necessary for the American economy and national security, and calls for
maintaining an adequate supply. RFK Jr. relented and praised the EO.
References:
Glyphosate
use in agricultural production: it’s contribution to global carbon dioxide
emissions. Graham Brookes. GM Crops & Food: Biotechnology in Agriculture
and the Food Chain. Volume 17, 2026 - Issue 1. Full article: Glyphosate use in
agricultural production: it’s contribution to global carbon dioxide emissions
What
to know about glyphosate, the herbicide behind a Trump executive order that’s
angered MAHA moms. Michal Ruprecht, CNN. February 24, 2026. What to know about glyphosate, the
herbicide behind a Trump executive order that’s angered MAHA moms
Glyphosate’s
Environmental Benefits: How the controversial herbicide saves wildlife and
where it still falls short. Dan Blaustein-Rejto. The Ecomodernist. March 13,
2026. Glyphosate’s Environmental Benefits -
The Ecomodernist
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