The idea of reducing carbon emissions by offsetting them with reductions elsewhere has become central to government and business strategies to tackle climate change. Yet this approach deserves serious questioning.
Fundamentally, offsetting assumes that emissions released now, which are stored away by biological processes over millions of years, can be diminished within the current carbon cycle through compensatory actions. Since the Kyoto Protocol, forest clearing and reforestation have often been promoted as solutions.
Planting trees to counteract deforestation, provide shade, stabilize land, and support biodiversity can help remove some carbon from the atmosphere in ways that would not happen otherwise. But this does not imply the planet can automatically absorb all fossil carbon produced by human industry. The notion that damage today can be “compensated” later elsewhere, a concept also seen in aquatic ecology, cannot be accepted at face value.
How does the carbon cycle work?
Globally, fossil fuel burning currently emits about 10 billion tonnes of carbon each year. If this pace continues, emissions could reach roughly 280 billion tonnes between now and 2050, far exceeding the maximum potential of natural carbon sequestration. Between 2015 and 2050, the amount sequestered is estimated to be about 38 billion tonnes.
Planting a tree only offsets the impact of another tree that is removed; it does not offset the extra fossil emissions. This practice highlights a fundamental limitation of relying on forestry alone to balance fossil carbon released today.
Before industrialization, carbon circulated in a dynamic balance, with inputs and outputs roughly matching and the total stored carbon remaining stable. The shift to coal, oil, and natural gas disrupted this balance, releasing carbon stored for thousands of years into the atmosphere.
“Carbon sequestration by plants, trees, soils and oceans can only reduce carbon in the current cycle, but not additional fossil carbon.”
Even though the carbon atom in a tree is the same as that in fossil fuels, the contexts are different. The fossil carbon that trees are expected to offset is a separate, distinct pool. Planting trees reduces the loss of carbon from another tree that has already been removed, and it does not eliminate fossil emissions. This reality also implies that widespread tree planting does not guarantee a future free of carbon pressure if fossil emissions persist. The long-term effect on land use may constrain land available for food production as forests replace other uses. Currently, forest clearing outpaces replanting, amplifying this concern.
There are significant risks including forest fires, storm damage, drought, and rising temperatures. These factors can destabilize forests and limit or even halt their capacity to sequester carbon.
carbon trading trap
The idea of “Net zero” is often criticized as a postponement or a form of self-deception if it relies on accounting tricks rather than real emission reductions. In some cases, subtracting the carbon sequestered by forests planted since 1990 can give a misleading picture of emissions being lower than they are in reality.
Net emissions can be misrepresented when sequestered carbon replaces pre-existing trees, and fossil emissions remain unoffset. The practice of trading credits, including so-called ghost credits, has shown that many credits do not correspond to real reductions in emissions. The central assumption—reducing fossil carbon in the current cycle—has been challenged by authorities that emphasize the permanence of added fossil carbon on human timescales.
More trees alone won’t do the trick
Beyond natural strategies, artificial carbon capture and storage techniques exist but require massive energy input, come with high costs, and show limited potential. Many attempts have fallen short. The IPCC notes that CO2 captured is often not permanently stored, and the net energy required for carbon capture reduces the overall energy yield from fossil fuels, which is already in decline. In the best-case scenario, even a full reforestation effort would absorb only a fraction of current annual emissions, roughly a decade’s worth, if at all scalable enough to offset ongoing fossil output.
Reversing deforestation and expanding planting can help, but planting trees while continuing fossil fuel emissions is not a solution. The only viable path is to stop emitting fossil carbon and to reduce dependence on fossil fuels altogether. The conversation around these topics continues to be debated by researchers worldwide, emphasizing practical, long-term strategies over quick fixes.
Source discussions in the literature highlight that eliminating fossil fuel use remains essential for meaningful climate progress. The emphasis is on real emission reductions rather than relying solely on offsets or plantings as a substitute for cutting fossil fuel use.
In summary, balance in the carbon cycle requires a combination of preserving existing forests, restoring degraded ecosystems, and, most critically, reducing fossil fuel emissions to prevent ongoing accumulation of atmospheric carbon.
Note: This summary reflects broader expert discussions on carbon dynamics and offsets, focusing on the need for transparent, verifiable emissions reductions and sustainable land-use practices.