19 February 2022 | New Scientist | 21There is a lively debate about how
UK farmland will need to change
to boost carbon dioxide removal.
About a fifth of agricultural land
should be turned over to tree
planting and other carbon
sequestration, says the UK’s
independent Climate Change
Committee, enabled by a shift
to more plant-based diets.
Some farmers, such as Andrew
Blenkiron in the east of England,
are already turning over land used
for cereal crops to fast-growing
Paulownia trees. Pat Brown, the
chief executive of plant-based
“meat” firm Impossible Foods,
is talking to UK farmers about
replacing pasture with trees
to store carbon. But a shift fromfood to forestry will be hard.
UK environment secretary
George Eustice says farmers are
being supported to remove CO₂
through the government’s Nature
for Climate Fund now and, longer
term, through the Landscape
Recovery scheme and private
green finance. “The key thing
really is to expand woodland
cover,” he says, pointing to
the government’s target of
30,000 hectares a year.
Peatland restoration is also
important, Eustice adds, along
with technology and innovation.
He cites a project in Cornwall
capturing methane from livestock
and using it instead of red diesel,
a fuel used in farm vehicles.From food to forestry
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Your guide to a rapidly changing world
newscientist.com/insightAn Extinction Rebellion
protest in London on
1 September 2020
for companies to remove and
store CO2, beyond private-sector
initiatives such as firms like
Shopify and Stripe paying for DAC
removals. That means, for the
most part, there is no “route to
market” for company boards
mulling investment decisions.
Then there are public attitudes.
The 108 people on the UK’s first
Climate Assembly in 2020, which
aimed to weigh the views of the
general public, were very coolrenewable electricity needed
for cars, heat and more.
The scale of the challenge is
huge. By 2050, the UK government
thinks engineered technologies
will need to remove between
75 and 81 million tonnes of CO2
a year, up from zero today. Even
getting to net zero by 2050 with
BECCS, DAC and tree planting is
a stretch, says Smith. But they are
our best bet, he says. Other ideas
aren’t worth banking on for 2050,
but may prove useful on longer
timescales. “Our children may
decide we need to unwind some
of the climate change we’ve
experienced, and go beyond
net zero to net negative. In which
case, having started on these
technologies will help,” he says.
There remain many obstacles.
Large-scale storage and transport
infrastructure needs to be built,
although in the UK and Norway,
the governments are already
working to enable the pipes and
vaults needed. “If we don’t make
progress on those this decade,
there’s a bottleneck later on,”
says Joffe. Old oil and gas
reservoirs mean the two countries
may end up as big stores for the
EU’s CO2, says Ruth Herbert at
the Carbon Capture and Storage
Association, a UK trade body.
Another issue is that there
are still almost no incentivesPJRNEWS/ALAMYUK cannot rely on such solutions
to remove millions of tonnes
of CO2 and meet current carbon
targets, she says.
In the short-term, that role will
fall to nature-based approaches,
mostly tree planting and peatland
restoration, says David Joffe at the
Climate Change Committee (CCC),
an independent group advising
the UK government (see “From
food to forestry”, right). The reason
such measures come first is that
they are inexpensive and can
take years to draw down carbon.
However, there is only so much
land, and so much carbon that
trees can absorb, meaning climate
targets won’t be met without
engineered removals in the
medium term too. The first big
prospect is bioenergy with carbon
capture and storage, also known
as BECCS, which energy firm Drax
wants to deploy in the north of
England to burn biomass for
power and pipe the CO2 into old oil
and gas reservoirs off the coast.
The second is direct air capture
(DAC), machines using fans, heat
and chemicals to take CO2 directly
out of the air, a technology that
Canadian company Carbon
Engineering plans to have running
at scale in Scotland by 2026.
“They are the main front
runners,” says Joffe. “Others
we regard as, to some extent,
speculative. Which is not to say
they cannot contribute, but we
don’t think they’re proven enough
to include in our scenarios.”
Keeping alternatives in play is still
worthwhile, he says, because there
are physical limits to how much
biomass can be grown in the UK
for BECCS. And DAC is energy
intensive, so too much deployment
in the next 15 years could consume
on engineered removals.
“The crucial thing in bringing
people along is to have a clear
public strategy to say this
is what the removals are for:
counterbalancing those
remaining emissions where
we just can’t get to zero, not
to allow companies off the
hook,” says Joffe.
Given all those hurdles,
“there is a world in which none
of this happens”, says Smith.
Two possible triggers for failure
are hostile public opinion
and governments not giving
incentives to scale up the
innovations that schemes like
the competition in the UK are
producing, he says. Fortunately,
Smith thinks that is unlikely,
not least because countries are
beginning to realise that avoiding
more dangerous climate change
means not just CO2 reductions,
but CO2 removal. “We essentially
need to solve this problem in our
generation,” says Smith. ❚90%
Share of global economy
with net-zero targets£100m
Funds for UK CO₂ removal
competition75-81m
Tonnes of CO₂ that the UK needs
to remove from the air in 2050