At the December 2021 convening of the U.S.-China High-Level Dialogue on Energy and Climate Change, delegates from China and the U.S. identified methane as an issue area with significant potential for shared learnings and one that may need significant support beyond the channels of national government engagement.
At COP26, the U.S. and China signed the U.S.-China Joint Glasgow Declaration on Enhancing Climate Action in the 2020s. The declaration included commitments between the two countries to cooperate on methane measurement, to exchange information on policies and programs for strengthening management and control of methane and to foster joint research on methane. It recognized the U.S. Methane Emissions Reduction Action Plan and committed China to developing a comprehensive and ambitious national action plan on methane prior to COP27.
At the request of Dialogue participants, WRI China and WRI U.S. each convened roundtables with experts from domestic national and subnational government agencies, industry, academia and the INGO community focused on two key sectors: agriculture and waste. Through the course of technical, policy and market-oriented discussions, experts identified several areas of concern and potential opportunities for international collaboration.
Methane emissions from agriculture comprise approximately 40% of total U.S. and Chinese methane emissions. The Food and Agriculture Organization of the United Nations (FAO) reports that approximately 66% of agricultural methane emissions come from enteric fermentation and 20% from rice cultivation. Methane emissions from agriculture globally equate to roughly four gigatons of CO₂ — equivalent of 8% of global greenhouse gas (GHG) emissions. According to U.S. EPA’s most recent data, municipal solid waste (MSW) landfills are the third-largest sources for methane emissions in the U.S. and account for more than 15% of the total inventory of methane emissions. In China, methane emissions from waste and wastewater account for roughly 10% of total methane emissions.
Opportunities to collaborate were identified across the range of emissions sources.
Promising Focus Areas for International Collaboration to Reduce Enteric Methane Emissions:
- Enteric methane inhibitors, including 3-Nitrooxypropanol (3NOP) and red algae, are gaining traction as effective in reducing enteric emissions. Some of the experts who participated in the roundtables have suggested that if studies are done in multiple parts of the world, enteric emissions-reductions strategies would be ready to be deployed within two to three years. The global price tag for this work was estimated to be $100-200 million.
- Improving feed quality, animal husbandry practices and herd structure management in low-yield settings could dramatically improve yield and thereby reduce methane emissions intensity, as evidenced by the successes of the Dairy Nourishes Africa pilot.
Potential Focus Areas for International Collaboration to Reduce Methane Emissions from Rice:
Rice cultivation was identified as a relatively low-cost mitigation opportunity in China and U.S. roundtables, and collaborative work has identified improving yield, optimizing water management, adjusting the time of straw being returned to the field and using biochar as significant opportunities. Increased cooperation could enhance and accelerate adoption of appropriate technologies and management practices.
Potential for International Collaboration to Reduce Methane from Waste:
Within the waste sector, one area of potential collaboration between the U.S. and China is building the economic case for the installation of anaerobic biodigesters. China has committed to establishing Zero-Waste Cities in 100 cities by 2025, but the program does not consider anaerobic biodigestion. Barriers to installation and investment include a lack of modeling demonstrating the amount of energy that the waste and wastewater sectors can produce — without these models, potential buyers do not trust the reliability of supply. Coupled with the lack of incentives or subsidies for biogas recovery, there are few market indicators encouraging biodigester installation and utilization. Knowledge-sharing in the policy space could be beneficial. California is a leader in developing regulatory incentives for renewable natural gas from biodigesters; there may be transferrable lessons learned between states like California and Chinese provinces.
Potential for International Collaboration on Remote Sensing:
A range of remote sensing collaboration opportunities were discussed. First, facility-level monitoring with remote sensing is in nascent stages in the U.S. and is also under consideration for regulatory purposes. These strategies could be shared with Chinese regulators. Second, the use of remote sensing to identify hotspots or outlier behavior was identified as an opportunity to support multi-sector methane reduction efforts. Finally, there is an opportunity for China, the EU and the U.S. to support data collection or provide methane emission data using their satellite technologies, providing emissions data to governments that do not have their own remote sensing satellite data. This type of multilateral collaborative project would frame data collection and synthesis not within the contentious context of compliance, but rather a framework of development and assistance via technology and capacity-building.
