Policy Strategies to Mitigate Climate Change by Reducing Global Methane Emissions

In the climate debate, the methane gas merits considerable attention as it contributes approximately half of the human-induced global warming in the short-term. A new study at IIASA reveals that global warming can be substantially reduced by implementing available technology that restricts the release of methane into the air.

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The study was recently reported in the Environmental Research Communications journal.

This could help alleviate some of the very expensive effects of climate change that are predicted in the few decades to come. If considerable reductions in human-induced methane emissions are to be achieved to fulfill the Paris Agreement, it is essential to know precisely where and from what sources emissions occur, which would help policymakers to start creating plans to mitigate methane and its effect on global warming.

To develop policy strategies to mitigate climate change through reductions of global non-CO₂ greenhouse gas emissions like methane, we need detailed inventories of the sources and locations of current man-made emissions, build scenarios for expected developments in future emissions, assess the abatement potential of future emissions, and estimate the costs of reducing emissions.

Lena Höglund-Isaksson, Study Lead Author and Senior Research Scholar, International Institute for Applied Systems Analysis

Höglund-Isaksson continued, “In this study, we looked at global methane emissions and technical abatement potentials and costs in the 2050 timeframe.”

The researchers used the IIASA Greenhouse Gases – Air Pollution Interactions and Synergies (GAINS) model to discover how well the GAINS bottom-up methane emissions inventory at source-sector and country level from 1990 to 2015 match top-down estimates of the global methane concentration quantified from the atmosphere.

Additionally, the research group intended to observe the amount of methane that would be emitted globally until 2050 if no further measures are taken to decrease emissions. The outcomes demonstrate that at the global level, the GAINS methane inventory compares well with the top-down estimate of the contribution of human-induced methane emissions to the concentration of methane in the air.

It is crucial to achieve a reasonable match between top-down and bottom-up budgets, both at the regional and global levels, for gaining the confidence in bottom-up inventories, which are a precondition for policy plans to be understood as “certain enough” by stakeholders in climate mitigation.

The researchers’ investigation showed a steady increase in emissions after 2010, confirming top-down measurements of increases in the atmospheric methane concentration in the recent past.

In this study, these are elucidated by elevated methane emissions from the production of shale gas in North America; increased coal mining in countries other than China, for example, Australia and Indonesia; and rise in wastewater and waste generation from economic development and growing populations in Africa and Asia.

Moreover, the outcomes revealed a small but strong increase in emissions from dairy and beef production in Africa and Latin America, pointing out at the difference in distributions of emission source sectors over different regions of the world.

Additionally, the outcomes revealed that without any actions to control emissions of methane, there would be a worldwide increase in emissions of about 30% until 2050. Although it is technically feasible to eliminate approximately 38% of these emissions by applying available abatement technology, a considerable amount of methane would still be released between 2020 and 2050, rendering it impossible to achieve global warming below 1.5 °C.

The scientists indicate that it is still possible to use the technical abatement potentials to realize significant reductions in methane emissions in the near-term and at a relatively low cost. About 30%–50% of future global methane emissions can be eliminated at a cost below 50 €/t CO₂eq. However, fossil fuel use will also have to be brought down to bring about a positive impact.

Technical abatement potentials are specifically restricted in agriculture, implying that it is necessary to address these emissions through non-technical measures, like behavioral changes to decrease the consumption of meat and milk, or socioeconomic and institutional reforms to make smallholder livestock herding a risk management means in South-East Asia and Africa.

There is no one-size fits all solution for the whole world. In the Middle East and Africa, for instance, oil production is a major contributor to methane emissions with relatively extensive potentials for emission reductions at low cost.

Lena Höglund-Isaksson, Study Lead Author and Senior Research Scholar, International Institute for Applied Systems Analysis

“In Europe and Latin America, dairy and beef production are the main sources with relatively limited technical mitigation potentials, while in North America it is emissions from shale gas extraction that can significantly contain emissions at a low cost. Our study illustrates just how important it is to have a regional- and sector-specific approach to mitigation strategies,” concluded Höglund-Isaksson.