54 Time September 23, 2019
carbon emissions. E.U.-funded rewilding
projects in Finland, the U.K. and Germany
are rewetting peatlands to turn them back
into carbon sinks.
Rewilding advocates are compet-
ing for investment with more modern
negative- emissions technologies. Doz-
ens of companies are developing carbon
capture and storage (CCS) technology, in
which machines use chemical processes
to filter CO₂ out of the air. The gas is then
used to make products or stored under-
ground, removing it from the atmosphere.
Swiss startup Climeworks, for exam-
ple, scrubs CO₂ from the air at plants in
Italy, Switzerland and Iceland, at a cost
of $500 to $600 per metric ton of CO₂. It
is then sold for use in greenhouses, soda
manufacturing and biofuel production, or
stored in rocks deep underground.
But most IPCC plans for preventing
more than 1.5°C of warming include a
different kind of CCS: bioenergy and
carbon capture and storage (BECCS),
which should account for the majority
of negative emissions by the end of the
century. BECCS power stations burn
trees and plants—which have sequestered
carbon while growing—to produce elec-
tricity, then trap the resulting CO₂ emis-
sions. The U.K. government has invested
$32 million in domestic BECCS projects,
including the first pilot program to launch
in the E.U., the Drax power station in the
U.K., which went online in February.
Currently, these high-tech methods
for removing carbon from the atmo-
sphere are expensive and so have limited
reach. Rewilding, at least at the moment,
is cheaper and more proven. Peatland res-
toration, for example, can trap a metric
ton of CO₂ per year for about $16.
Despite the low cost, however, there
are obstacles to rewilding on a meaning-
ful scale. “There’s a limited amount of
land that we can do restoration on,” says
Simon Lewis, a professor of global change
science at University College London.
The mudflats and salt marshes at Wal-
lasea currently bury around 1,200 met-
ric tons of CO₂ a year—the equivalent of
the per capita emissions of only around
200 Brits in 2018. The U.K. would need to
rewild wetlands about 10 times the size of
the entire country’s land area to zero out
national carbon emissions.
Large-scale nature restoration also
doesn’t yet have real political support.so-called afforestation, the planting of many of one species
of tree where there was none before, in regular lines. Many
afforested trees are regularly cut down and used to produce
timber, paper or biofuel.
Rewilding advocates say afforestation, while offering simi-
lar carbon- sequestration capacity to reforestation, offers little
benefit to wildlife and carries risks. Studies have found that
the large-scale planting of nonnative trees in Canada and
China have disturbed natural ecosystems, worsened wild-
fires and depleted groundwater levels.
Meanwhile, other landscapes have been neglected. “I
think politicians like planting trees because it’s a very clear,
simple action,” says Timon Rutten, head of enterprise at
Rewilding Europe, a Netherlands- based NGO that oversees
nature- restoration schemes from Portugal to Bulgaria. “But
peatlands, wetlands and grasslands are just as good or some-
times even better at storing carbon.”
Northern European countries shelter large expanses of
peatlands—sometimes called moors, bogs or mires—that
perhaps offer the greatest opportunity for natural climate
mitigation. The plants that grow on the surface of peatlands
sequester, or absorb, carbon dioxide as they grow. When they
die, the decomposing plants do not leach carbon back into the
atmosphere but get buried in waterlogged bogs, compressing
into a new layer of peat. These habitats cover about 3% of the
globe but contain more stored carbon than all other kinds of
vegetation on earth combined. They sequester 370 million
metric tons of CO₂ per year. But 15% of the world’s peatlands
have been drained for agricultural use, or so that their peat
could be burned to power generators, emitting carbon diox-
ide in the process. The dried-out peatland that’s left behind
then releases stored carbon into the atmosphere; peatlands
now account for almost 6% of annual global human-caused
Negative-emissions
plants like this
one by Swiss firm
Climeworks filter
CO₂ directly out of
the air