Peking University, June 16, 2026: Planting trees is often seen as a simple way to "store carbon" and slow climate change. But what happens when that tree eventually dies and its carbon is released back into the atmosphere? Does the climate still benefit in the long run? Led by He Yue from Institute of Carbon Neutrality at Peking University (PKU), a new Nature study establishes a scientific framework to judge whether temporary carbon storage can deliver real climate benefits.
Why It Matters
As countries and companies race toward net-zero targets, carbon dioxide removal (CDR) has become a core strategy in global climate action. However, most currently deployed CDR technologies only deliver temporary carbon storage, sparking widespread debate over their actual contribution to climate mitigation.
Key Findings
The research team from PKU's Institute of Carbon Neutrality and the International Institute for Applied Systems Analysis (IIASA) developed a novel framework for assessing the climate benefits of non-permanent carbon removal based on impulse response functions (IRFs). The study is the first to quantify the extent to which temporary CDR can offset emissions from non-carbon dioxide greenhouse gases.
The team introduced a new metric—the Offset Ratio (α)—which measures the amount of temporary carbon removal required to compensate for the warming impact of a given greenhouse gas emission.
The results show that temporary carbon storage is not a one-size-fits-all solution. It is effective for short-lived greenhouse gases such as methane, whose warming effects align with the cooling provided by temporary carbon sinks, but cannot fully offset gases that remain in the atmosphere for centuries.
The study identifies a critical atmospheric lifetime threshold of 30.9 years, which separates long-lived greenhouse gases from short-lived ones. Over a 100-year assessment period, offsetting the warming from 1 kilogram of methane requires removing 498 kilograms of carbon dioxide through 20-year storage or 101 kilograms through 100-year storage.
Future Implications
This study provides a physics-based framework for crediting temporary CDR activities, which can be highly valuable to sectors such as agriculture and waste treatment, where methane emissions pose persistent challenges. Moreover, the study clarifies that temporary carbon storage can only serve as a supplementary measure, rather than a replacement for cutting greenhouse gas emissions at the source.
*This article is featured in PKU News "Why It Matters" series. More from this series.
Read more: https://www.nature.com/articles/s41586-026-10607-3
Written by: Ma Xuan
Edited by: Wong Jun Heng, Chen Shizhuo
Source: PKU News (Chinese)
Journal
Nature