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Permanence of carbon credits

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Being aware of the tenets constituting a high integrity carbon credit is important to avoid claims of greenwashing while increasing accountability and transparency in an opaque market. There are ten tenets recognised by the Integrity Council for the Voluntary Carbon Market (IC-VCM). Two of these, additionality and double counting, have been explained in previous posts. Today, we cover the principle of permanence.

What is Permanence?

Briefly, this refers to the timescale for which a tonne of carbon will remain captured or avoid emission.

Why is it important to account for the permanence of a credit?

Around 25% of emissions released by human activity remain in the atmosphere for hundreds to thousands of years. In addition to the longevity of CO2, its global warming potential (GWP) is also cause for concern. Since longevity and warming potential are often referred to conjointly, the GWP of a GHG is measured on a timescale. Most commonly, policy applications use a 100 year timeframe.  Therefore, high quality offset standards calculate carbon credits on a GWP100.

Hence, a carbon credit is required to at least match this timeframe. I.e., the permanence of a carbon avoidance or removal credit is required to be of at least 100 years. Otherwise, allowing any program to subsequently protect the sequestered carbon for something less than 100 years is equivalent to awarding 100 years’ worth of climate benefits without a corresponding requirement to actually deliver 100 years’ worth of climate benefits.

Can the permanence of a credit be assured?

The IC-VCM launched a public consultation in summer 2022 on the draft Core Carbon Principles. The aim of the resulting Assessment Framework was to “provide a credible, rigorous, and readily accessible means of identifying high-quality carbon credits that create real, additional and verifiable climate impact with high environmental and social integrity.”

Under this framework, it has been stated that “the GHG emission reductions or removals from the mitigation activity shall be permanent, or if they have a risk of reversal, any reversals shall be fully compensated.”

These guidelines were drafted by the IC-VCM to counter the risks of short-term credits, and to safeguard those with high risk factors. Human activity alongside natural disasters can lead to carbon leakage. For instance, when sequestering carbon through afforestation, there is a natural risk of fires. In this event, the carbon which was being sequestered by trees and soil would be released back into the atmosphere. It is due to this concern that the Gold Standard does not issue forestry-based REDD+ carbon credits.

How do we mitigate for the risks of reversal?

To mitigate the risk of reversal from fires, logging or disease, standards include a buffer provision. This means, projects with a risk of reversal are required to set aside a percentage of credits in a buffer or insurance pool. Under the Gold Standard, for instance, this buffer is 20%. In the event of a reversal, these credits from the buffer compensate the loss of the carbon sink.

Plannet Zero and Permanence

Different verifying standards have different methodologies to ensure permanence. The requirements will vary according to the type of project, too. Therefore, as a consumer, you should not worry about the permanence of a carbon credit, as when you procure from an approved retailer, all their carbon credits will meet the standards required.

Plannet Zero, for instance, exclusively sources its carbon credits from standards that mandate its projects’ use these buffers, helping buyers to be confident in the permanence of their offsets.


Edited by Tiffany Cheung

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