Published 2 months ago.
About a 8 minute read.
Using enhanced rock weathering to draw down carbon from the
atmosphere, UNDO aims to spread enough crushed rock on farmlands by 2025
to permanently remove 1M tons of CO2.
Every year, humanity releases an alarming 40 billion tonnes of carbon
into the atmosphere — driving global temperature increases. This mounting crisis
is exemplified by the long-term average temperature, which has already soared to
1.2°C above pre-industrial
with a perilous 1.5°C milestone looming on the horizon. In 2021,
atmospheric carbon levels surged to a concerning 415 parts per
marking a staggering 20 percent increase in just 42 years and pushing us ever
closer to global tipping points.
The urgency for action is palpable, accentuated by the scientific consensus
demanding the removal of 10 billion tons of carbon per year by
to curtail the most devastating impacts of climate change. To restore our
planet's delicate equilibrium, we need innovative solutions that actively remove
carbon from the atmosphere. This is where companies such as
UNDO come into play.
Founded in 2022, UK-based UNDO is already a leader in the exploding
— in this case, demonstrating the potential of enhanced rock weathering
(ERW) to undo the climate-changing impacts of carbon dioxide.
“At UNDO, our ultimate goal is to reach gigaton-removal scale by spreading
CO2-capturing rock on agricultural land around the world,” Nick
Acfield, Account Manager
at UNDO, explains to Sustainable Brands®. “When we talk to companies,
the initial focus has to be on their decarbonization and switching away from
fossil fuels — we stress that even as a carbon-removal organization. But this
reduction is not enough; we are going to have to remove carbon from the
ERW is situated at the intersection of nature-based and engineered
carbon-removal solutions. The former includes techniques such as tree
— a quintessential, natural method of carbon capture. While economical, these
solutions have their limitations — being that trees only sequester CO2 for their
lifespan and don’t capture their full potential for many years. They release
their stored CO2 during decomposition or burning, often caused by logging and
clearcutting for farmland.
On the other end of the spectrum, direct air
(DAC) offers an effective and metered, though costly, means of mechanically
extracting CO2 from the atmosphere and securely sequestering it underground.
However, DAC can be energy-intensive — so, until we successfully shift our
global power mix to
energy-heavy technologies are counterproductive in terms of reducing reliance on
climate-changing fossil fuels.
Approaches such as ERW offer a compelling compromise. This technique accelerates
the speed and efficiency of the natural process of rock weathering, which
gradually absorbs carbon over geological timescales. In doing so, it provides an
avenue for sustainable and relatively rapid carbon removal — presenting an
attractive solution to mitigate the impacts of climate change. By focusing on
enhancing the carbon-sequestration ability of agricultural lands, UNDO is
building on the work of fellow ERW innovators such as
— which is applying the technique to coastal systems.
“People know that plants and trees absorb CO2; but most of the carbon on Earth
is stored in rocks or sediments or as bicarbonate — far more than is in organic
matter like plants or trees,” Acfield explains. “And rock weathering is one of
the most natural ways of regulating the amount of CO2 that's in the atmosphere.”
Enhanced rock weathering is a process where CO2 in the air is
absorbed by raindrops, forming weak carbonic acid (H2CO3). When this rain falls
on silicate or mafic rocks, the carbonic acid reacts with the minerals —
converting CO2 into stable bicarbonate ions. These ions eventually find their
way through soils and groundwater into the ocean, where they help to deacidify
our oceans and remain for long geological periods — roughly 100,000 years.
This process is a long-lasting and effective way to remove CO2 from the
atmosphere, in contrast to plants that take up carbon temporarily and release it
when they die. In fact, weathering already naturally removes approximately 1
billion tons of
from the atmosphere each year.
UNDO sources its crushed silicate rock, primarily volcanic rocks such as basalt,
from quarries. Commonly used in construction and road-building, powdered basalt
rock is left behind in large quantities. UNDO acquires this material from quarry
stockpiles and applies it to farmlands for practical use.
“When this rock is spread on farmland, it breaks down — releasing important
plant nutrients in the process. This enriches the soil, improves its pH levels
and increases crop yields for farmers,” Acfield says. “And of course, because
the reactive surface area of the rock is much greater, the CO2 capture process
is exponentially faster.”
These vital nutrients (namely phosphorus, potassium, magnesium and calcium) act
as natural fertilizers and prevent the need for other expensive soil inputs such
as liming. Along with sequestering carbon, ERW supports farmers, creates local
employment opportunities, and benefits biodiversity — furthering several UN
Sustainable Development Goals.
Along with these impressive co-benefits, UNDO's solution offers permanence — as
it locks away carbon for thousands of
versus carbon stored in soil — which can be easily released
of farmland, extreme weather or other disturbances. It is scalable due to the
abundant supply of silicate rocks such as basalt, which is the most common rock
on Earth. It is also highly sustainable, as UNDO uses existing infrastructure
and machinery to carry out its operations — which the company claims boast a >
90 percent carbon efficiency; and it continually strives to optimize to remove
more carbon with fewer emissions.
Over the past 18 months, UNDO has reached more than 70 employees and has spread
150,000 tons of rock — which is expected to sequester 35,000 tons of CO2 over
time. The sequestration process typically takes around 20 years for basalt rock,
with the majority occurring in the first 7 to 10 years. UNDO is researching
other rock types that, though not as abundant, have shorter weathering timelines
to capture more CO2 faster.
UNDO sources its rock from quarries in Scotland, Northern England,
Canada and Australia — creating another revenue stream for local
suppliers. The company takes pride in trying to keep benefits within the
communities it operates: In addition to purchasing crushed rock from local
quarries, it spreads it within 20 miles of where it was sourced — only hauling
the rock further when absolutely necessary — and employs local contractors
throughout the carbon-removal process. The company gives farmers the rock for
free, which reduces their expenditure on fertilizers while simultaneously
enhancing their crop output.
Importantly, UNDO regularly tests its rock for potentially toxic elements such
as heavy metals or materials that could damage the soil or seep into water
“We've now got too much demand from farmers in the UK, which is a really good
place to be. Farmers are getting FOMO in the communities;
because if a neighborhood farm is doing something new, it always sparks
competitive interest,” Acfield explains. “And there's been quite a lot of
evidence from farmers concerning the benefits to their land and crop — being
able to harvest more hay, for example.”
UNDO is currently scoping regions of interest to further franchise and scale. It
has developed a proprietary, global screener which overlays silicate rock
feedstocks, quarry operations, farmland availability and more to assess
potential next areas of expansion.
UNDO's business model relies upon corporate buyers who wish to meet their
net-zero goals through buying carbon
The company’s unique appeal lies in its capacity to address the quality and
effectiveness concerns inherent in the voluntary carbon
Quality assurance is crucial due to the market's perceived opacity and
reputational issues. UNDO’s carbon credits stand out — as they have multiple
co-benefits and are much more price-competitive than other high-permanence
Transparency and accountability in carbon removal are key priorities for UNDO.
Its comprehensive measurement, reporting and verification (MRV) system,
supported by a world-class science team, ensures that companies buying carbon
credits can confidently claim their legitimacy. MRV forms the foundation of the
business, helping to prevent greenwashing and establishing scientific
credibility in the carbon-removal process.
UNDO collaborates with a diverse range of companies seeking reliable
carbon-removal solutions to fulfill their carbon removal targets. The company
exclusively partners with companies firmly dedicated to reducing their emissions
first and using carbon removal to reach net zero. Earlier this year, UNDO became
first ERW supplier, announced a $12
funding round led by Lowercarbon Capital, and
announced a $1 million contract
from Stripe — one of the world’s leading carbon-removal
purchasers. And just last week, it announced a landmark
with British Airways, CUR8 and Standard Chartered in a
first-of-its-kind pilot for financing carbon removal.
"This is a really exciting time for UNDO. We are seeing a lot of interest from
many corporations, and we are partnering with scientific bodies and academic
institutions around the world,” Acfield says. “It's heartening to witness the
world's collective determination to combat climate change and embrace innovative
solutions. Together, we're forging a path toward a more sustainable and hopeful
Published Dec 20, 2023 2pm EST / 11am PST / 7pm GMT / 8pm CET
Scarlett Buckley is a London-based freelance sustainability writer with an MSc in Creative Arts & Mental Health.