Global trend of methane abatement inventions and widening mismatch with methane emissions

nature climate change Analysis https://doi.org/10.1038/s41558-024-01947-x Global trend of methane abatement inventions and widening mismatch with methane emissions Received: 27 June 2023 Jingjing Jiang1, Deyun Yin 1,2,3 , Zhuoluo Sun , Bin Ye4 & Nan Zhou5 1 Accepted: 2 February 2024 Published online: 19 March 2024 Check for updates Substantially reducing methane emissions is the fastest way to repress near-term warming and is an essential prerequisite for reaching the 1.5 °C target. However, knowledge about the global invention trend, sectoral and national distribution and international diffusion of methane-targeted abatement technologies (MTATs) remains limited. On the basis of patent data, we identify more than 175,000 MTAT inventions applied between 1990 and 2019 by 133 countries or dependent territories. Our results revealed that after sustained growth of more than fourfold, the number of global high-quality MTAT inventions declined by 3.5% annually from 2010 to 2019. The sectoral and national-level distributions of MTAT inventions and methane emissions are strongly mismatched. Additionally, the international diffusion of MTATs is 11.1% lower than that of overall climate change mitigation technologies and most transfers occur between developed countries or flow to China, South Korea and Brazil; however, other developing countries and the least developed countries are rarely involved. The amount of atmospheric methane (CH4) has surged rapidly since 2005 and hit a new record high in 2022 (ref. 1). The globally averaged atmospheric concentration of methane has more than doubled since preindustrial times and is responsible for approximately one-third of global warming2–5. Methane, although powerful, is a short-lived climate pollutant with an atmospheric lifetime of roughly one decade6. Such a short life cycle means that methane abatement can gain immediate payoffs from decreased atmospheric abundance and thereby weakened climate forcing. Substantially reducing anthropogenic methane emissions has thus been identified as the fastest way to curb near-term warming and the most effective strategy for pursuing the 1.5 °C target7–9. Moreover, anthropogenic methane emissions contribute to the formation of ground-level ozone, causing nearly half-a-million premature deaths each year and impairing agricultural productivity10,11. Hence, decreasing methane emissions will provide cobenefits for improving public health and alleviating food shortages. Given the great leverage of methane in mitigating climate change and facilitating the achievement of several sustainable development goals, the COP26 launched the Global Methane Pledge initiative, which aimed to abate anthropogenic methane emissions by at least 30% by 2030 (ref. 12). A host of technologies and measures have been proposed in the recent literature, presenting a general blueprint for methane abatement13–15. The potentials and costs of methane-targeted abatement technologies (MTATs) have been broadly examined for major sectors or systemwide13,15–18. Despite the considerable estimated potentials9,19–21, it has been acknowledged that technologies available at present fall short of the methane abatements required for the 1.5 °C target7,13,22–24. Hence, expediting innovation in MTATs is urgently needed to close such a gap. Recent studies based on patent data have shown global trends in climate change mitigation and adaptation technologies25–27 and energy technologies28–30. However, knowledge about global inventions in MTATs remains limited. School of Economics and Management, Harbin Institute of Technology (Shenzhen), Shenzhen, China. 2Innovation Economy Section, World Intellectual Property Organization, Geneva, Switzerland. 3Research Institute for Data Management & Innovation, Nanjing University, Suzhou, China. 4School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China. 5International Energy Analysis, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. e-mail: 1 Nature Climate Change | Volume 14 | April 2024 | 393–401 393 Analysis https://doi.org/10.1038/s41558-024-01947-x Table 1 | Technology field, brief definition and amount of MTAT inventions in 1990–2019 Technology field Brief definition Amount of all patented inventions Amount of high-quality inventions Agriculture Technologies which aim to reduce methane emissions from rice cultivation, land use and livestock or to increase carbon sinks by afforestation and reforestation, such as breeding, methane-inhibited irrigation, rumen fermentation manipulation, manure management and interplanting technologies. 2,112 179 Fossil energy Technologies which aim to reduce fugitive, vented or flared methane emissions from coal mines or oil and natural gas supply, such as methane extraction, low-concentration gas use, leak detect and repair, satellite monitor, blowdown capture, portable flare and green completion technologies. 7,614 2,339 Waste treatment Technologies which aim to reduce methane emissions from wastewater and solid waste treatment, such as methane-reduced wastewater and sludge treatment, landfill gas collection, waste to energy or fertilizer technologies and organic waste separation and recycling technologies. 156,684 25,896 Biomass Technologies which aim to reduce methane emissions from biomass, such as bioethanol, biodiesel, integrated biofuel utilization and other biomass-to-fuel technologies, as well as biomass densification, biomass boiler and stove and other high-efficient biomass combustion technologies. 27,365 8,087 Cross-cutting enabling Methane reduction or removal technologies that can be deployed beyond specific sectors or facilitate the application of other technologies, such as carbon accounting, pricing and management, methane tax, direct air capture of methane and atmospheric methane destruction technologies. 6,886 2,653 175,963 32,616 Overall MTATs High-quality inventions refer to inventions that are filed in at least two countries or regions to seek to be protected internationally. The sum of inventions in all technology fields does not equal the number of overall MTAT inventions because some inventions may pertain to several technology fields. Moreover, there are large mismatches between growth sources and abatement potentials in terms of global methane emissions. Driven by expanding and increasingly affluent population, the agricultural sector is widely projected to be the dominant growth source of methane emissions7,13,21. However, the expected technological potential of methane abatement in this sector is very limited, urgently calling for new breakthroughs22,31–33. Additionally, most growths in future methane emissions are projected to come from countries currently less developed or poverty-stricken, such as the constantly increasing emissions caused by livestock farming, waste disposal or rice cropping from African, Latin American and Asian cou (...truncated)