As methane emissions deplete rapidly compared to carbon dioxide emissions, cutting them can help quickly lower global warming. Furthermore, cutting methane emissions is both cost-effective and easy.
The Climate & Clean Air Coalition estimates that human-caused methane emissions could be reduced by as much as 45 percent this decade, helping prevent nearly 0.3 degrees Celsius of global warming and keeping pace with Paris goals.
Preventing Leaks
Methane emissions decline rapidly compared to carbon dioxide levels, making reducing methane one of the fastest and cost-effective methods of combatting climate change, according to scientists. Methane reduction forms part of Paris Agreement’s goal of keeping global warming to 1.5 degrees Celsius above preindustrial temperatures.
Methane emissions resulting from human activities primarily come from fossil fuel production, waste disposal and agriculture. In the US alone, oil and gas production account for 23% of emissions followed by coal mining (12%) and livestock (8%) as major sources. Marcellus Shale region in Pennsylvania remains a primary source of methane and has become the focus of state and industry efforts to limit leakage of this harmful gas into the atmosphere.
But despite best intentions and some progress, much work remains. Even if oil and gas companies found and repaired all known leaks, experts believe there would still be many more undiscovered ones; many methane emissions from drilling operations — such as when valves or storage tanks remain open — don’t produce visible evidence; leaving industry players to speculate where these leaks may be taking place, says Mark Zondlo of Princeton University Engineering Faculty. “A lot of guessing by industry players as to where and how often these leaks may be occurring,” according to Professor Zondlo.
GAO conducted an investigation to gain a better understanding of methane emissions from federally leased and operated land, interviewing agency officials and industry representatives, reviewing academic studies and documents, as well as reviewing seven selected state efforts at regulating methane emissions. As a result of its investigation, the GAO provided a proposal which would cut 41 million tonnes of methane between 2023 and 2030 – equivalent to about 920 million metric tons of carbon dioxide emissions.
That would be an immense achievement: it would reduce greenhouse gas levels in the atmosphere by approximately 5 billion tonnes – nearly one third of what climate scientists consider necessary to limit warming to 1.5 degrees Celsius and avoid dangerous tipping points that would accelerate climate change further.
Detecting Leaks
methane gas emissions enter the atmosphere from human activities including oil and natural gas production, coal mining, agriculture, landfills, solid waste management and wastewater treatment plants. Once considered an unavoidable byproduct of these activities, methane emissions are now seen as harmful greenhouse gasses that must be reduced to combat global warming. Technology exists that detect leaks at their source to minimize pollution levels and limit methane pollution.
Fugitive methane emissions make up nearly 25% of global greenhouse gas emissions and have increased twice as quickly since 2007. Methane traps 80 times more heat per molecule than carbon dioxide and has an extremely short lifetime in the atmosphere – so controlling its release is one of the key ways we can protect against catastrophic climate tipping points.
There are numerous readily available solutions to reduce methane emissions from fossil fuels, landfills and agriculture. Most involve fixing leaks, reducing venting or capturing methane instead of releasing it to the air – most measures have very low costs; indeed some oil and gas production companies even generate profits by preventing leaks and capturing methane instead of releasing it into the environment.
Researchers have developed numerous tools to detect methane leaks, from infrared cameras and pressure sensors to acoustics. These devices are typically deployed alongside surveys to ascertain the full scale of methane emissions from sites and identify problem locations while devising effective plans to lower those emissions.
Methane fees offer one of the most promising solutions, serving as a tax on emissions of methane and other pollutants at their source. Similar to existing business taxes, this policy could rapidly reduce emissions from fossil fuels, landfills, agriculture and livestock. A recent study showed that even a 45 per cent decrease in methane emissions by 2045 could prevent 260,000 early deaths, 775 000 asthma-related hospital visits and 73 billion hours lost due to extreme heat.
Repairing Leaks
Although much attention has been focused on carbon dioxide emissions, methane reduction should also be prioritized. Methane’s decomposition in the atmosphere occurs rapidly and poses greater short-term greenhouse gas risks than CO2. Furthermore, its decay increases risk for dangerous tipping points that could destabilize climate systems altogether.
The Global Methane Assessment finds that human-caused methane emissions could be reduced by 45 per cent this decade, avoiding nearly 0.3 degC of warming and keeping Paris Agreement’s goal of not exceeding 1.5degC within reach. Lowering methane emissions also has positive health benefits and cost reduction effects; one million tons of methane reduced annually can prevent approximately 1,430 premature deaths, 90 asthma hospital visits and 145,000 tons of crop losses annually.
However, unlike carbon dioxide emission strategies, many of the methane reduction measures highlighted by this report are readily available and easy to implement. For instance, within the fossil fuel sector there are already established policies which can drastically decrease methane emissions such as leak detection and repair programs, equipment mandates and regulations limiting non-emergency flaring/venting activity – some even being profitable for companies!
Project Drawdown also highlights other climate and air quality solutions that can further decrease methane emissions, such as switching to renewable energy, improving energy efficiency, or decreasing food loss and waste–which are easier to scale up than targeted methane reduction measures and can bring multiple advantages.
Not only can these strategies reduce methane emissions, they can also keep ground-level ozone – an air pollutant linked to heart attacks, asthma attacks and death – within safe levels. A 45 per cent reduction of both methane and ozone would prevent approximately 260 000 premature deaths each year as well as 775 000 asthma-related hospital visits plus 73 billion hours lost labour due to smog pollution.
Capturing Methane
Methane emissions, the second-biggest contributor to global warming, must also be reduced as these increase even as CO2 decreases.
Methane emissions have more of an effect than CO2, as their effect is far-reaching and much greater in quantity. A pound of methane traps 25 times more heat in the atmosphere than CO2. Thus it’s imperative that emissions be kept to an absolute minimum.
Capturing methane from the atmosphere is another effective strategy for cutting emissions, and Stanford University researchers have developed a system using porous crystalline structures to soak it up. If successful, this technique would restore atmospheric concentrations back to those pre-industrialization and lower global warming by an estimated one sixth.
Researchers envision a system that would trap methane entering chambers from large volumes of air forced in by electric fans (powered by renewable sources). According to them, this will convert methane to less harmful carbon dioxide emissions while providing time to address more pressing climate feedback loops that increase Earth warming.
Current sources of methane emissions include landfills and oil and natural gas production facilities, where it can be released as waste gas. Researchers are exploring other means of sequestering this greenhouse gas as a greenhouse solution; one approach involves using bacteria to convert it to liquid form that can then be stored, transported and sold on.
Methane removal requires massive investments, but is achievable within our means. A recent project to sequester carbon dioxide began operating in April and according to McKinsey analysis would cost about USD 11 billion a year in order to fully mobilize methane reduction measures across all oil and gas sector operations worldwide.
Other techniques, like catalytic converters that transform natural gas into methanol, can be costly and complex. Furthermore, such processes often rely on high temperatures or precious metals that are limited in supply; while others rely on chemical reactions which take time and may break down over time.
