Scientists express ‘concern’ about ‘misuse of new approaches to methane’
Climate mitigation risks are being “undermined by misuse of new approaches to methane” according to a group of international scientists.
A letter signed by over 40 scientists from 10 countries, including Ireland, warned against using "Global Warming Potential Star (GWP*)” as a metric.
GWP100 is a more commonly used metric at present.
Last year, an international cohort of farming groups (including Irish representatives) called for a split-gas approach when reporting greenhouse gas (GHG) emissions.
The group’s chair Kate Acland said at the time: “The use of GWP100 is particularly concerning in the New Zealand setting where methane emissions are already reducing.
“GWP100, which works well for long-lived gases like carbon dioxide, is inaccurate when measuring the warming impact of short-lived gases such as methane, especially when those emissions are trending down.”
This week’s statement from the group of scientists expressed “deep concern that this crucial methane mitigation is being undermined globally by efforts to redefine approaches to greenhouse gas metrics and climate targets”.
It added: “Across several high-emitting countries - notably the United States, the EU, New Zealand, Ireland, Brazil, Uruguay, Paraguay and Argentina policymakers and industry groups are promoting new approaches, such as ‘Global Warming Potential Star (GWP*)’.
“While these approaches are rooted in legitimate scientific methodologies, they are increasingly being used to justify revised climate targets that aim for ‘temperature neutrality’ or ‘no additional warming’.
“In practice, these targets facilitate weakening ambition below what can readily be achieved by high-emitting countries. This entrenches historical privilege and distorts the Paris Agreement's core temperature and equity principles.”
Methane emissions
The scientists’ letter also refers to “grandfathers methane emissions”.
This was decried by an Irish scientist last year, Dr. Colm Duffy, honorary lecturer in agri-sustainability, School of Biological and Chemical Sciences and Ryan Institute, University of Galway.
At the time, Dr. Duffy and his colleagues called out the new “temperature neutrality”, also known as "no additional warming", which allows Ireland to maintain a high share of global agricultural methane emissions while claiming to meet its climate targets.
Dr. Duffy said: “The science shows that the new policy essentially grandfathers methane emissions - meaning a country’s future share of warming is based not on equity or ambition, but on historical share of emissions."
This week’s letter said: “The advancement of these new approaches would allow major methane emitters to continue producing large quantities of greenhouse gases while claiming ‘climate neutrality’."
According to the statement, this is done "by focusing only on changes in warming over time, rather than total warming, inappropriate applications of GWP* and ‘no additional warming’ grandfather current methane emissions, rewarding countries and companies with high historical methane emissions and penalising countries with low emissions who need space to develop”.
The letter warned that, if widely adopted, these methods would “downplay the significant climate impacts of methane-intensive sectors, such as ruminant livestock and fossil fuel extraction; allow countries and companies to meet nominal ‘neutrality’ targets while their contribution to warming continues; legitimise minimal methane reductions and undermine progress toward the Global Methane Pledge (-30 % by 2030)”.
The scientists’ letter urged governments to “reject the inappropriate application of GWP*, including using ‘temperature neutrality’ as a basis for national targets or reporting”.
Legislative framework
A spokesperson for the Department of Climate, Energy and the Environment (DECC) told Agriland:
"As a member of the EU, it should be noted that Ireland operates in a distinctly different legislative framework to countries outside of the EU, such as New Zealand, which governs how we measure and act on emissions to achieve our climate targets".
The European Climate Law commits the EU to achieving climate neutrality (or net zero GHG emissions) by 2050.
The spokesperson said any decisions on Ireland’s carbon budgets must align with this overarching framework.
"Domestically, the methodology for the accounting of greenhouse gases in Ireland is set down in Regulation S.I. No. 531/2021 and this requires that all greenhouse gases, including methane, are calculated and accounted for in a manner consistent with agreed EU and international standards.
"This government is committed to delivering on Ireland’s responsibility to address the climate crisis and the Programme for Government 2025 recognises the scale of the challenge Ireland faces and sets out a comprehensive agenda for responding to the climate crisis," the spokesperson added.
Carbon budgets
The Joint Oireachtas Committee on Climate, Environment and Energy has undertaken detailed scrutiny of the Second Carbon Budget Programme, as proposed by the Climate Change Advisory Council (CCAC).
In its extensive report, the committee presented 38 recommendations spanning multiple sectors including agriculture, electricity, transport, Just Transition and buildings.
The department said the recommendations, and the proposal by the Council itself, will need to be carefully evaluated before the Minister for Transport and Minister for Climate, Energy and the Environment Darragh O'Brien brings any further proposals to government.
"That is what we are now focussing on, in addition to the work that has already been taking place over the course of the past few months.
"Minister O’Brien notes the extensive feedback received to date from a wide range of experts and stakeholders on the Carbon Budget proposals, including on the issue of temperature neutrality.
"These are important factors which are being given due consideration in the context of the process for developing the Minister’s finalised recommendations to government on the next budget programme," the department spokesperson said.
