How Temporary CO2 Removals Can Counter Methane Warming

When greenhouse-gas cuts are discussed, carbon dioxide (CO2) usually receives most of the attention. Methane, however, is the faster-acting threat: over the short term it warms the planet far more powerfully, despite remaining in the atmosphere for less time than CO2.

New research is built around that distinction. Its premise is straightforward: instead of viewing short-lived carbon-removal schemes as an inadequate replacement for CO2 cuts, they should be used for their particular strength - counterbalancing methane’s brief but intense warming effect.

Methane’s distinctive climate impact

Methane and CO2 act very differently once they enter the atmosphere. Methane delivers a much greater immediate warming effect.

It is responsible for substantial near-term warming, a crucial issue for the coming decades and for impacts affecting people today and in the near future, including heatwaves, crop stress and coral bleaching.

However, methane’s influence diminishes with time as it breaks down in the atmosphere.

CO2 behaves in the reverse way. Although a tonne of CO2 does not produce such a dramatic initial temperature rise, it persists for an exceptionally long period. From a climate perspective, it represents a long-term commitment.

Managing warming both in the present and in the future therefore requires measures suited to the timescale of each challenge, rather than a single approach for every problem.

The challenge of “temporary” projects

Nature-based carbon removal, including afforestation and reforestation, is frequently criticised - and there are valid reasons for that criticism.

If a project is no longer maintained, is destroyed by fire, felled or simply comes to an end, the carbon removed from the atmosphere may be released again. This is why opponents describe such projects as “temporary” and why some argue that they are too uncertain to qualify as genuine climate action.

The researchers acknowledge this concern. Their argument instead turns it on its head: when temporary removal is used to offset a temporary climate pollutant, its limited duration is precisely what makes sense.

Using short-term removals to “cancel out” CO2 can also lead to ethical and practical difficulties.

There may be a short-lived gain today, while future generations are left to deal with lasting consequences if the stored carbon is released once more. Put simply, the burden would be pushed into the future.

Matching climate timescales

The team proposes properly matching the relevant timelines. Methane creates strong warming over the short to medium term before its effect declines, so CO2 removals lasting for a similar period should be used to counteract that warming.

They contend that a carefully designed removal project lasting roughly 30 years can align remarkably well with methane’s short-lived temperature effect.

In comparison with permanent carbon removal, 30-year projects are generally less expensive, simpler to verify and avoid requiring a pledge to preserve carbon storage indefinitely.

Permanent removals, such as some geological storage methods, may be expensive and depend on economic assumptions extending far into the future. They also involve a monitoring obligation lasting “forever”, which is hard to guarantee in real-world conditions.

A methane offset formula

The study’s central figure is that 87 temporary removals of one tonne of CO2 lasting 30 years are estimated to be broadly equivalent, in temperature impact, to 1 tonne of methane emissions.

This matters because it turns an uncertain question - whether methane should be cut directly or offset - into something closer to a decision-making framework.

Reducing methane may be challenging or slow in certain industries, with agriculture being the familiar example. In such cases, temporary removals could act as a bridge, limiting near-term harm while methane reductions are scaled up.

Supporting nature-based climate goals

The argument is not that methane should not be reduced. Rather, achieving climate targets means managing warming across several time horizons.

The researchers also suggest that this method could bring additional funding to nature-based projects by assigning them a role that matches their real strengths.

“Meeting the goals of the Paris Agreement requires reducing temperatures in both the short and long term,” said Ben Groom, an expert in biodiversity economics at the University of Exeter.

“Rather than seeing the temporary nature of land-based carbon removals as a weakness, we show that it can be an advantage when used to counter methane’s short-lived warming.”

“This approach could unlock new climate finance for nature-based solutions and deliver immediate relief from temperature stress.”

Temporary CO2 removals are not a magic solution for carbon dioxide. Yet, when deployed strategically, they can serve as a practical measure rather than a disputed loophole.

In essence, it is climate accounting with more appropriate timing: pair the warming being offset with a solution that endures for roughly as long as the problem itself.