54 The Economist November 6th 2021
International
ForestsandclimatechangeUp a tree
T
he world’sleaders may quail at clos
ing coalfired power plants or raising
petrol prices, but they can be relied upon to
embrace one ally in the fight against cli
mate change: the tree. For all his claims
that climate change was a hoax, even Do
nald Trump, as president, championed an
initiative to plant a trillion trees. Yet there
is cause for scepticism about the pact, an
nounced at the Glasgow climate summit
this week, to put an end to deforestation
before the decade is out.
The world has seen similar unenforce
able declarations before. In 2014 govern
ments, companies and ngos promised to
halve deforestation by 2020 and end it by
2030. The first target was missed, making
the second, to which many of the same
countries have now resubscribed, a
stretch. And those trillion trees remain an
achievement chiefly of alliteration.
Still, this week’s announcement is more
credible than previous pledges. This time,
Brazil and Indonesia, both deforestation
hotspots, have signed up (India has not).
Rich countries have promised to stump up
cash to protect and restore forests. All signatorieshave recognised that indigenous
people are best placed to care for forests
they live in. At least as significant is a com
mitment from the private sector, including
financial institutions, to uproot deforesta
tion from their supply chains and invest
ment portfolios.
Slashing, burning or thinning trees or
otherwise degrading ecosystems accounts
for 11% of emissions. Standing forests, by
contrast, serve as carbon “sinks”, breathing
in a net 7.6bn tonnes of carbon dioxide
each year. Programmes to plant and protect
forests will be essential to meeting the Par
is agreement’s targets of limiting global av
erage temperature rises to “well below 2°C”
above preindustrial levels. The Paris
agreement calls for the amount of carbon
sequestered each year in sinks to equal or
exceed humanmade emissions “in the
second half of this century”.
This has spurred national and cor
porate strategies to hit netzero emissions
through forestry, from restoring carbon
rich peatlands to developing agroforestry.
China and India have vast treeplanting
programmes. Russia, home to 20% of theworld’s forests, wants to use them to offset
its sizeable greenhousegas emissions.
Bhutan, which plausibly claims to have
reached netzero, can do so only by taking
credit for a heavy dose of forestry. Myan
mar is in a similar situation.
The problem is that the world lacks a
shared, sensible system for valuing the
contribution of trees to sequestering car
bon. This is an accounting puzzle of great
complexity. Depending on whether and
how it is solved, trees could wind up being
either part of the solution to global warm
ing or part of the problem.
The accounting standards now in use
and new standards for a carbon market in
which forestry offsets can be traded are on
the agenda in Glasgow. But quantifying the
carbon sequestered by any project, ensur
ing benefits are durable, providing consis
tent, transparent data and weeding out bo
gus schemes all pose thorny problems.
The natural carbon cycle of forests is
selfregulating. Trees soak up CO 2 from the
atmosphere, then return some of it when
they decompose or burn in wildfires. Over
time, new plants absorb that CO 2.
Humans are distorting things in two
ways. Deforestation and forest degradation
increaseemissions by releasing stored car
bon. And the 1.11.3°C of global warming
that has come with the 2.5trn tonnes of CO 2
already added to the atmosphere further
increases carbon emissions: more warm
ing means faster decay and more fires.
At the same time, carbon dioxide from
fossil fuels gives plants more to work with,K YIV AND SÃO PAULO
If the world really loves forests, it should put a price on their carbon