Dr. Joeri Rogelj:

I thank the committee for the opportunity to speak at this meeting. I am director of research at Imperial College's Grantham institute for climate change and the environment and the lead author of IPCC reports and emissions reports from the UN environment programme. In addition, I am one of the members of the European Scientific Advisory Board on Climate Change, but I want to emphasise that I am participating here in a fully independent capacity.

We find ourselves today in a world that is more than 1.1°C warmer compared to pre-industrial times. As we experience today, this increase is caused by human activities and causes many extreme weather events - heatwaves, droughts, and flooding, which are exacerbated by this warming. These extremes lead to damage to crops and infrastructure, and also cause animal and human suffering. Methane emissions are a large contributor to this, second only to CO2. The IPCC wrote in its latest report that methane emissions from human activities, like fossil fuel use or agriculture, contribute about 0.5°C to the warming the world experiences today. As other experts, including Professor Thorne, have explained, methane is different from CO2 in that it does not accumulate in the atmosphere in the same way. As a consequence, much of the current 0.5°C of methane warming is not the result of past emissions having accumulated over centuries, like for CO2, but of activities that are taking place today and about which we are making decisions on whether they continue, increase, or strongly decrease their contribution to climate damages and suffering.

The calculation of methane emissions is therefore an extremely important topic.

Deep methane reductions are essential. Pathways that meet the goals of the Paris Agreement all require deep methane reductions over the next decades. Put differently, the remaining carbon budget for 1.5°C, that is, the total amount of carbon dioxide we could still emit while keeping global warming below 1.5°C, will be effectively zero if methane emissions are not kept in check. No sector is off the hook to make this happen. Fortunately, scientifically speaking, the calculation of methane emissions is a solved problem. The committee heard about this from other experts as well. Well-established scientific guidelines have been published by the IPCC on how to estimate a country’s methane emissions. It is also undisputable and uncontroversial that reporting emissions separately, in tonnes of methane actually emitted, is the least ambiguous and most scientifically accurate way of reporting methane. Currently, the latter approach is also the default way in which countries report their individual methane emissions to the UN, or the UNFCCC in this case.

Challenges arise when greenhouse gases are being aggregated. Under the Paris Agreement, countries aim to achieve global net-zero greenhouse gas emissions. In the EU, this goal is also known as reaching climate neutrality. To calculate when this goal will be achieved, methane and other greenhouse gases must be converted to an equivalent amount of carbon dioxide emissions before they can be aggregated. If emissions are aggregated with the current standard approach used in the UN and the EU, that is, using a metric called the 100-year global warming potential, GWP, the IPCC tells us that achieving net-zero greenhouse gas emissions results in global warming first peaking and then gradually declining. This basically means leading to a reversal of the problem. Other methods, such as GWP*, can lead to other results. For instance, if we switch to some of these newer methods, global warming will merely stabilise but not decline when net-zero greenhouse gas emissions are reached. The choice about how emissions of methane are calculated can therefore weaken the ambition of the Paris Agreement and of the EU's climate neutrality target. We must be honest about this choice when we discuss the calculation of methane emissions.

A second challenge is that these new methods to calculate methane emissions can sometimes, perversely, reward historically high methane polluters. These polluters would be less incentivised to reduce their methane emissions or could be rewarded with emissions credits that take past polluting behaviour as a reference point. This goes against basic notions of fairness and equity and against the scientific evidence that deep methane reductions are necessary to meet the goals of the Paris Agreement. We must remain honest here as well. Fortunately, the scientific literature here also presents solutions to how policy can be designed to avoid these pitfalls.

The scientific evidence clearly shows that deep reductions in methane emissions, including from the agricultural sector, are necessary to meet the Paris Agreement. The evidence also shows us how methane warming from current emissions is an active contributor to climate damage and current climate suffering around the world. Any choice about how to calculate methane emissions and how to incentivise or disincentivise action on methane emissions should keep these overarching concerns in mind. I thank the committee and I look forward to responding to any questions.