Durability, not permanence: Why we must act on natural climate solutions now

As scientists committed to advancing climate solutions, we are increasingly concerned that misunderstandings surrounding the concept of “permanence” are being used to dismiss natural climate solutions.

We cannot wait for perfect certainty before deploying climate solutions at scale. The cost of delay – ecologically, economically and climatically – is far greater than the risk of carbon reversals.

Concerns over permanence – focused on the chance that carbon stored in forests and other ecosystems might one day be released – have become a red herring. The relevant question isn’t whether risk exists but whether it can be understood, managed and compensated for.

It can – and our ability to do so will only continue to improve through a combination of science, smart policy decisions and innovative financial products.

Binary thinking – permanent versus impermanent – once offered a convenient abstraction. Today, it obscures more than it illuminates. Climate science and carbon market architecture have evolved and so should our vocabulary.

We should instead focus on durability: how long carbon remains out of the atmosphere for a given intervention, what mechanisms exist to manage the risk of its return and what scale of implementation would be needed to realize climate benefits given those realities.

Scientists agree that we need more robust accounting but these accounting options should accommodate different interventions with different durabilities.

It’s essential to acknowledge that varying degrees of durability provide distinct, quantifiable climate benefits. Not all climate solutions need to last forever to be valuable. What matters is how long carbon is stored, at what scale and how effectively we can compensate for eventual losses.

This is how society handles risk in nearly every domain – from finance to engineering – and the same principle applies here.

Much of the scepticism about the durability of natural climate solutions stems from a narrow perspective. We think about individual trees or forest plots that may die, burn or blow down. But natural climate solutions function at the landscape, regional and global scales.

While any single stand of trees is vulnerable, entire ecosystems can be remarkably resilient.

In fact, the response of ecosystems at large scales to increased atmospheric CO2 has, until recently, been to increase their stored carbon, driven by factors such as CO2 fertilization and longer growing seasons.

Even dead trees represent a previously underappreciated and very large carbon store.

Moreover, we have no viable alternative at this point, when climate action is critical, to large-scale natural carbon storage. For decades, our natural lands have quietly and reliably absorbed about a third of humanity’s fossil fuel emissions despite the fires, pests, storms and disturbances that appear in the headlines.

Allowing these systems to degrade or deferring protection until every accounting challenge is solved is shortsighted at best and reckless at worst. Reducing the capacity of natural climate solutions today means more work for us tomorrow.

Carbon markets have long used compensation mechanisms, such as buffer pools, to account for and address unexpected losses.

These systems require that a portion of climate benefits from each intervention be set aside in a pooled reserve of credits to insure against reversal events, functioning like an insurance policy that doesn’t prevent accidents but helps ensure all parties are made whole again.

This mechanism can maintain atmospheric integrity, protect the buyer’s investment and uphold trust in the system even when individual projects experience setbacks.

Can these mechanisms be improved? Yes. But they are already real, workable and improving. What’s more, buffer pools are just one of many tools available. As carbon markets mature, we can – and should – import well-tested financial instruments from other sectors: reinsurance, long-term risk pooling and contractual guarantees, among others.

Managing permanence risk is about practicality, not science. Continually improving science can inform us about the when, where and what of risk, enabling more strategic, informed decisions regarding policy and financial planning.

The point is not to claim that reversals won’t happen. It’s to recognize that we can manage them, just as we do with other risks that are uncertain in timing but inevitable in occurrence.

Science can help us quantify not only the risk of reversal but also the cost of delay. Both matter and when weighed together, it becomes clear: the greater danger lies in failing to deploy the solutions already at hand.

In other words, the greatest risk we face today is not whether nature can store carbon for a century or more. It is that we fail to act – now while nature still can help stabilize the climate.

Insisting on an unattainable standard of permanence for individual projects and programmes ignores both the urgency of the climate crisis and the tools we already have to manage uncertainty.

We must also correct a dangerous misperception: if a solution isn’t permanent, it’s worth nothing. This is false.

Building a natural climate solution that stores carbon for many decades while delivering water, biodiversity and livelihood co-benefits is far more valuable than doing nothing. Critically, these decades matter – because the next 20 to 30 years will determine whether we can avoid the worst of climate change.

Just look at the Eastern Deciduous Forest Biome in North America, where a century of reforestation has locked away massive amounts of carbon, to see the scale and integrity that can be achieved.

As scientists, we reject the false choice between natural and engineered climate solutions. We need both. Nature is available now at enormous scales that allow for global participation in climate mitigation while also offering climate adaptation and livable communities.

This is not a plea to lower standards. We must ensure that all solutions represent real, additional climate benefits, that the durability of these benefits is accurately accounted for and that any subsequent emissions of stored carbon are effectively addressed.

However, we must also be honest about what science can and cannot say – and not expect scientific answers to solve what are ultimately policy questions.

Perfection should not stymie progress. Natural climate solutions are already delivering results with science-backed strategies that can ensure high levels of durability. They complement, rather than compete with, engineered technologies.

The climate emergency will not wait for perfect solutions. Why wait for a perfect technology when nature has already provided us with a powerful one?

The following individuals co-authored this piece: Dr Brian Buma, Environmental Defense Fund; Dr Susan Cook-Patton, The Nature Conservancy; Peter Ellis, The Nature Conservancy; Dr Jason Funk, Conservation International; Dr Bronson Griscom, Conservation International; Dr Steven Hamburg, Environmental Defense Fund; Dr Sara Kuebbing, Yale University; Dr Jigme Tenzin, Fauna & Flora; Dr Sarah M Walker, Wildlife Conservation Society; Dr Lahiru S. Wijedasa, BirdLife International.