While increases in CO2 levels have marginally slowed, in 2021 levels of methane (CH4) grew at their fastest pace in two decades. This surge in methane emissions has resulted in a renewed effort for urgent mitigation measures. In 2021, at COP26 in Glasgow, the Global Methane Pledge was initiated and 110 countries signed up to the pledge. The aim is to reduce methane emissions by 30 percent by 2030 compared with a 2020 baseline although scientists say that a 45 percent cut in emissions is necessary to keep to 1.5°C of global warming.
“Methane is more than 25 times as potent as carbon dioxide at trapping heat in the atmosphere. Over the last two centuries, methane concentrations in the atmosphere have more than doubled, largely due to human-related activities. Because methane is both a powerful greenhouse gas and short-lived compared to carbon dioxide, achieving significant reductions would have a rapid and significant effect on atmospheric warming potential.”
United States Environmental Protection Agency
Methane Emissions
Around 40 percent of methane emissions come from natural sources but 60 percent from human activity of which the main contributors are agriculture (40 percent), energy (35 percent) and waste (20 percent).
Agriculture
Around 32 percent of all man-made methane emissions are estimated to originate from the digestive system and manure management of large, farmed animals, mostly cattle. There are some technical solutions such as feed, animal health, husbandry and manure management, although the benefits of these are not easily quantifiable.
Meat production plays a disproportionate role in methane emissions and the difference between meat and plant based agriculture is stark. Agricultural emissions are set to rise steeply and, unless addressed now, it will constrain the efforts to meet the 1.5°C target. Cutting livestock emissions is critical and yet few governments have policies to reduce them. Governments generally have not grasped the importance of drastic methane reduction measures or applied measures to livestock. Herd size reduction is the most efficient solution to agricultural methane emissions. In Europe, Germany and The Netherlands have herd reduction targets.
About 80 percent of agricultural land globally is used to raise animals or the crops to feed them, although livestock produces less than 20 percent of the world’s supply of calories. The ongoing deforestation necessary to feed the rising demand for meat, particularly beef, is an ecological disaster. In addition, red meat consumption is considered to be above healthy levels in much of the world’s populations. A shift towards a plant-based diet would improve the health of populations as well as significantly decreasing methane in the atmosphere. As the meat and dairy industry is concentrated with a few companies in charge of much of the market, governments could drive targets for emission reduction with fiscal measures. They could also change the way food is procured in public institutions such as prisons, schools and hospitals.
Waste
Methane is produced when biodegradable materials such as food, plant clippings, wood, paper and human waste break down in landfill sites or in the sewage treatment sector. Waste prevention is the most important way to reduce related methane emissions. For example, a recent food-waste-prevention law in France fines supermarkets that exceed a set cap for discarded food. If food is discarded it can be redirected to people in need or turned into jams or sauces or used in other imaginative ways.
“Collaboration between food banks, grocery stores and local government in Milan, Italy, for example, has led to 130 million tonnes of food waste saved annually in just three years, putting the city well on its way to achieving its goal of 50 percent food waste reduction by 2030.”
Methane Matters: A comprehensive approach to methane mitigation
Where there is waste, it is crucially important to separate out organic materials for composting or to turn it into animal feed where the waste is generated whether that is in the home, a public institution or industrial setting. Composting can prevent up to 99 percent of methane that would otherwise be released from landfill sites. Most methane is emitted from active landfill sites. Emissions from closed sites can be controlled by a biologically active cover, such as compost, which encourages microbes to digest the methane as it rises.
Energy
Phasing out fossil fuel extraction is by far the most important way to reduce methane emissions and improve air quality. According to the World Health Organization (WHO), 99 percent of people worldwide live in areas where air pollution exceeds WHO limits. Ambient air pollution accounts for an estimated 4.2 million excess deaths each year. In the energy sector, 5 percent of energy leaks contribute to 50 percent of methane emissions. As the change to renewable energy sources continues, leak detection and repair in the oil and gas extraction supply chain is crucial, as well as capturing methane from both active and inactive coal mines.
Global Methane Reduction Strategy
Global and national responses are required as this surge in methane emissions must be tackled at scale. There are three approaches: measurement, reporting and verification (MRV); national methane action plans; technical and financial assistance.
International monitoring can include the use of satellites to identify super-emitter events and gather data. Global and national data could be shared internationally underpinning scientific research and national action plans. Governments should take on board the crucial need for methane reduction by developing national methane action plans based on latest research and tailored to their national situation. Financial assistance to developing countries, including access to the latest research for all policy makers, will enhance a global response.
Co-benefits
There is good news. Action to decrease methane emissions has many benefits. Methane is a primary contributor to the formation of ozone at ground level. Cutting emissions would prevent many thousands of deaths and hospital treatments due to breathing difficulties. It would also increase crop yields which are suppressed due to pollution. Societies with minimal waste, a healthy plant based diet, renewable energy and ecological sustainability would benefit us all. In addition, the Global Methane Assessment estimates that 30 percent of the necessary methane reduction can be achieved with either low or negative costs.
Action Now is Critical
This is the critical decade for climate action. Methane is a short-lived but extremely potent gas with many times more warming potential than CO2 over a 20-year time span. The rapid reduction of methane emissions is a low hanging fruit for making a real inroad into climate warming. Many of these interventions in energy, agriculture and waste are readily available and low cost. The strategies needed to cut methane emissions have attendant resultant benefits for us all. Governments across the world need to take these actions seriously, work together on a global scale and support developing countries with scientific and financial aid.
