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International
The Economist November 6th 2021
Forests and climate change
Up a tree
KYIV AND SÃO PAULO
If the world really loves forests, it should put a price on their carbon
T
he world’s leaders may quail at clos ing coalfi red power plants or raising petrol prices, but they can be relied upon to embrace one ally in the fi ght 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 fi rst 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 chiefl y 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 sig
natories have recognised that indigenous people are best placed to care for forests they live in. At least as signifi cant is a com mitment from the private sector, including fi nancial 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 the
world’s forests, wants to use them to off set 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 off sets can be traded are on the agenda in Glasgow. But quantifying the carbon sequestered by any project, ensur ing benefi ts 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 CO2 from the atmosphere, then return some of it when they decompose or burn in wildfi res. Over time, new plants absorb that CO2. Humans are distorting things in two ways. Deforestation and forest degradation increase emissions by releasing stored car bon. And the 1.11.3°C of global warming that has come with the 2.5trn tonnes of CO2 already added to the atmosphere further increases carbon emissions: more warm ing means faster decay and more fi res. At the same time, carbon dioxide from fossil fuels gives plants more to work with,
