Going carbon neutral by planting a trillion trees will make our climate problem worse says Kathleen McAfee.

Will planting trees save the planet from global warming? Billionaires attending the 2020 World Economic Forum in Davos and even Donald Trump, seem to think so. The call from Davos to plant “a trillion trees”, mostly in tropical regions, reflects an international trend of pledges to go carbon neutral or reach zero-net carbon. Oil companies, airlines, governments, universities, and individuals around the world promise to offset the greenhouse-gas emissions they produce by paying for tree-planting or conservation of existing forests, especially tropical rainforests.

A headline-making paper in Science declared last year that massive afforestation is “the best climate change solution available– a claim that has since been amply debunked by environmental scientists. This has not stopped pundits and press officers from citing new tree-planting and tree-protecting promises as evidence that corporate leaders are taking climate change seriously and shifting their operations onto paths toward sustainability. Few seem aware that most saplings planted in recent mass reforestation schemes did not survive, or that new tree monocultures harbour little biodiversity and compete with land for food production. None cite research showing that carbon uptake by the world’s intact forests has been declining as Amazonian and other tropical forests become more saturated with carbon dioxide.

Fascination with forest-based carbon offsetting as a strategy against global warming runs deeper than public relations. Climate optimists increasingly advocate “natural climate solutions” based on forest preservation and “climate smart agriculture” meant to boost the capacity of soils and pastures to store carbon. Not all such proposals to achieve zero-net carbon call for financing by tradable offset credits but many do. They are based on the notion that activities paid for by sales of offsets can absorb or prevent the release of sufficient carbon dioxide to compensate for continuing emissions at some other location by the companies that purchase the offsets.

Why offsets don't work
Overlooked amid the country pledges and corporate self-congratulations is the simple fact that offsets do not slow climate change because they do not reduce the amount of carbon dioxide in the atmosphere. The carbon removal that offsets pay for is counteracted by the equivalent amount of greenhouse gases that credit buyers can emit while claiming that their activities are “carbon neutral” thanks to their use of the credits. Thus, at best, the use of offsets results in zero change in emissions. More often, the carbon storage or emissions avoidance that offsets pay for are only partial and transient. There are many reasons for this.


Production of the commodities most responsible for forest loss – palm oil, soy, cattle, minerals, and pulpwood – can be moved to unregulated locations as long as demand exists and other jurisdictions do not restrict it.


Offset credits for avoided deforestation are often issued for conservation activities that would have happened anyway, regardless of any projects or policies financed by offset sales.


A forest-carbon transaction can be completely reversed by a single event, like a fire, by changes in government, or government policies that encourage forest destruction.

Perverse incentives

Governments and landowners frequently exaggerate past deforestation or expected rates of new deforestation in order to increase their expected income from carbon-credit sales.

Conflicts of interest

Offset project developers, certifiers, and others who make their living from carbon markets have an incentive to ignore or minimise problems in order to report project success to those who employ them. The result is that when offsets are used to justify continued emissions by offset buyers, total global emissions actually increase (except in rare cases when buyers opt to retire carbon credits instead of using them to comply with policies that limit emissions). Yet sellers of offsets commonly claim that they reduce emissions. Intentional or not, this sleight-of-hand distracts attention from the need for genuine emissions reductions.

Prominent US environmental organisations are among the most active proponents of offsets and international emissions trading for forests. Other advocates include the World Bank, private investment banks and other brokers and speculators in carbon finance, and the carbon-accounting consultants and offset-project entrepreneurs who have carved out a niche as middlemen between offset buyers and sellers. This carbon-trading lobby is calling for a global carbon-compliance market between cash-poor tropical countries and industrial polluters that face emissions limits under cap-and-trade and other carbon-pricing regimes. They assume that conservation success depends mainly on money, and expect that the potential for carbon-market profits will persuade the private sector to come up with the funding that governments have failed to provide.

“Few seem aware that most saplings planted in recent mass reforestation schemes did not survive.”

The UN Paris Agreement, the world’s main multinational climate-mitigation effort, includes the Katowice Declaration on Forests. It describes better forest management as ”a keystone in achieving a balance between anthropogenic emissions by sources and removals by sinks”. That implies, misleadingly, that carbon storage in vegetation can substitute substantially for the very rapid reductions in emissions that the UN climate body says are urgently needed.

Article 6 of the same Paris pact is meant to provide broad rules for governments that want to trade credits for their climate good deeds, such as preserving forests, with other countries. But disputes about how to quantify forest-based credits and avoid double-counting, where more than one government claims credit for the same climate action, have stymied the Paris plan talks two years in a row. Until they are resolved, carbon-credit trades between member countries will not count toward countries’ claimed “reductions” under the Paris pact.

The case of forest conservation schemes under the rubric of Reduced Emissions from Deforestation and Degradation (REDD+) exemplifies the folly of forest carbon offsets. REDD+ was launched in the late 1990s as a “market-based” climate strategy. It was designed to create profit opportunies by taking advantage of global inequalities– participating investors could buy forest-conservation credits cheaply in developing countries and sell them for more in industrialised countries. But with no global carbon cap to limit the supply of carbon credits, the prices of these permits to pollute have been far too low to attract investors or limit emissions by offset-credit buyers.

Today REDD+ is a highly-subsidised hodge-podge of hundreds of UN, World Bank, and private programmes and projects that pay landholders and governments for their forest conservation promises. Although widely hailed as a relatively cheap and easy means of climate mitigation, REDD+ has failed to achieve demonstrable climate gains after 15 years of experimentation in dozens of countries. In many cases, poor farmers and forest dwellers have been denied access to the resources they rely upon to make way for REDD+ projects; others have been forcefully displaced for “carbon farms”: plantations of fast-growing trees that produce offset credits for sale, at least until the trees are harvested.

The thinking behind conservation financed by carbon trading aligns with that of conventional environmental economists who see emissions trading between industrialised and would-be developing countries as a conservation bargain. They reason that it is much cheaper to pay poor people and governments in developing countries to plant trees than it would be to compensate businesses in wealthy countries for phasing out fossil fuels. But conservation schemes based on this version of economic efficiency have, predictably, come to naught: profits from expanding forest-destroying industries consistently exceed the modest revenues from sales of low-priced, carbon-offset credits. Thus, forests conserved by offsetting schemes disappear when export agriculture and other extractive industries become more profitable.

Meanwhile, annual epidemics of fire devastate millions of hectares of forests in Amazonia and Southeast Asia, releasing the carbon that was temporarily stored in trees and adding more planet-cooking gasses to our overloaded planetary carbon sink. Not all these forests were under REDD+ or similar contracts to provide carbon-sequestration “ecosystem services” for sale, but those that were covered by such arrangements gave us a double dose of global warming. That is because carbon offset credits are rarely invalidated by such events: buyers of offset credits commonly claim greenhouse gas “reductions” as if the equivalent amounts of carbon dioxide were stored forever hence in the jungles of Indonesia, Congo, or Brazil.

“Forests conserved by offsetting schemes disappear when export agriculture and other extractive industries become more profitable.”

We can expect to see more such folly if national and subnational governments add or continue to accept forest-based offsets in their emissions-trading programmes. Consider the consequences of forest-based offsets under the state of California’s much-praised cap-and-trade policy.

California allows polluters extra emissions’ leeway if they invest in offsets, four-fifths of which have been based on forest management projects in the US or Quebec. Even where these North American forests are untouched by fire, recent analysis suggests that as much of 82% of the offset credits generated there are “false credits” that do not represent long-term carbon storage. Because logging and other forest-degrading activities are likely to be displaced to other forest tracts – “leakage” – credits issued to owners do not fully compensate for the extra greenhouse gases released by the Californian companies that use those credits. It has also become clear that the use of offsets – and cap-and-trade more broadly – has added to a glut in permits to pollute that is slowing California’s modest progress in reducing its total emissions.[1]

Despite that, California’s regulators want to expand the state’s offset policy to allow capped entities to purchase forest-based offset credits from national and provincial governments in Brazil and elsewhere in the tropics. The state’s Tropical Forest Standard (TFS) is a proposal to develop rules for such offsets. It is based on the REDD+ model but with the idea that deals between subnational governments, covering entire states or provinces, can produce better results than individual REDD+ conservation projects. In effect, the TFS would outsource part of the burden of mitigating global warming from California, a major importer, producer, and exporter of fossil fuels, to communities and governments in Amazonia and other parts of the global South – but without reducing the state’s own greenhouse gas emissions.

Nevertheless, conservation organisations, spearheaded by the Environmental Defense Fund, have joined oil and gas industry lobbyists and carbon-trading entrepreneurs in support of the California TFS. After contentious debates, the TFS was narrowly approved in late 2019 by the state’s climate regulators in the midst of alarm over the conflagrations in Brazil. But strong opposition from environmental justice organisations and many scientists, and growing skepticism among state legislators and academics about the effectiveness of offsets, may prevent its implementation.

“Another key to forest conservation is expansion and enforcement of the rights of indigenous peoples, whose record of forest protection is better than that of any other kind of land-use governance.”

Research that evaluates the TFS proposal in light of the track record of REDD+ and jurisdiction-wide tropical forest conservation programmes has found that the TFS, as designed, would replicate most of the main flaws that have plagued REDD+ programmes. Consequently, tropical forest offsetting, if linked to California’s cap-and-trade, would not represent the “real, additional, permanent, quantifiable, verifiable, and enforceable” reductions that California law requires.

Instead, the TFS would exacerbate environmental injustice. As scientists and grassroots activists have been pointing out for years, California polluters emit toxic particles and gasses along with their greenhouse gasses. Any system that allows them to pollute even more would mean more harmful air, worse health, and shorter lives in the low-income communities where the big polluters tend to be located.

Furthermore, policies that prioritise the use of land for carbon storage impose a carbon ontology upon forested regions. Under this paradigm, carbon sequestration becomes the greatest value and primary purpose of landscapes and the eco-social systems that are interdependent with them. Thus the California proposal, like past REDD+ and like the newer, offset-funded tree-planting schemes, also poses potential dangers to the peasant and indigenous communities whose survival practices stand in the way of carbon-first calculations.

Where conservation and carbon-sequestering farming practices are embedded in local lifeways and livelihoods, carbon storage in vegetation is more likely to contribute to climate stability than are massive tree-planting and offsetting schemes. Such sustainable carbon sequestration be encouraged through international grants and government policies that support the organisations and the livelihoods of small and medium-scale farmers – still the world’s main food producers – and that enable them to continue or adopt climate-enhancing, biodiversity-supporting agroecological farming practices.

“Financing such schemes by trade in carbon offsets is worse than doing nothing.”

Another key to forest conservation is expansion and enforcement of the rights of indigenous peoples, whose record of forest protection is better than that of any other kind of land-use governance, including national park systems in the tropics. A third essential requirement for slowing tropical deforestation is ending the government subsidies and other promotions of ecologically-destructive mineral and agricultural exporting. A counterpart to this is the reduction of rich-country imports of forest-killing tropical commodities such as palm oil and beef, as well as fossil fuels.

Planting a trillion trees, or similar putative solutions that would enable industries to achieve “carbon neutrality” or “net zero emissions”, do not slow global warming. They merely displace the burden of coping with climate change onto people and places that are so politically weak or impoverished that they have to sell their own natural environments. Financing such schemes by trade in carbon offsets is worse than doing nothing. It harms the most vulnerable and enables climate policymakers to rationalise their avoidance of real climate solutions: forceful, government-coordinated policy to phase out fossil fuels, with very stringent, very fast-falling emissions caps, public buy-outs, nationalisations of fossil-fuel stocks, and massive public investments in zero-carbon energy.

For decades now, advocates of such strong climate action have been told that the world cannot afford it. The world’s response to the Covid 19 pandemic is showing that when the crisis comes home to the centres of power, the impossible becomes doable almost overnight. The climate crisis is coming home to power, too.


  1. Cullenward, D. et al. (2019). Tracking banking in the Western Climate Initiative cap-and-trade program Environmental Research Letter 15 124037 ; Leslie, J. (2020). Why California’s climate solution isn’t cutting it.


Kathleen McAfee

Kathleen’s research is about “selling nature to save it”: climate cap-&-trade, carbon offsets, and alternative approaches linking climate change, public health, food, and global environmental justice. She was a co-founder …

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