President Joe Biden announced on September 17, 2021 that the United States and the European Union are working to commit to reducing methane emissions by at least 30% within this decade, and urged countries around the world to join this year before the United Nations climate summit later.
This move is a major event for efforts to mitigate climate change and for health. Although methane is not as abundant as carbon dioxide, it is a more effective greenhouse gas, warming the earth, and a source of unhealthy air pollution.
Climate scientist and physicist Drew Shindell explained the urgency of reducing methane emissions and how the benefits of reducing methane emissions far outweigh the costs.
Why is methane a problem, and is this goal sufficient?
Methane emissions have been rising rapidly, and studies have shown that they need to be reduced by nearly half by 2030 to achieve the Paris Climate Agreement’s goal of keeping global warming below 1.5 degrees Celsius (2.7 degrees Fahrenheit) at the lowest cost. This means that the world needs to turn around quickly.
If the new commitment is widely adopted and implemented, it will greatly change the world’s methane development trajectory. This is an ambitious minimum goal, and ideally, it must be significantly more than 30% to increase the chance of methane following the 1.5 C path.
The good news is that by reducing these emissions, the world will benefit a lot.
Methane is a potent greenhouse gas, but it is also a precursor of surface ozone, which is a toxic air pollutant. Therefore, reducing methane can improve the quality of the air we breathe while reducing climate change, and the effect is almost immediate.
Methane is also very valuable. If you collect methane from a landfill, you can get a source of income there. To capture it from leaking natural gas pipelines, it will pay for itself, because that is what these pipelines are all about-they transport methane as natural gas.
With technologies already available today, the world can reduce methane emissions from fossil fuels, agriculture, and decaying waste by 45% within ten years. This will avoid a warming of 0.3 degrees Celsius (0.5 degrees Fahrenheit), which may not sound like much, but it is one-fifth of the 1.5 degrees Celsius budget of the Paris Climate Agreement.
So you get climate benefits, you get public health benefits, and it’s also an economic victory for the company that captures methane.
This is not like rocket science. Most of the methane released comes from natural gas pipelines and storage, oil and gas pumping, and landfills-and these are problems that the company knows how to solve. In addition, recent satellite and aircraft data indicate that emissions from many sources are greater than previously thought, especially in the energy sector. This shows that active efforts to reduce methane may bring more benefits than originally estimated, and allow countries to far exceed the 30% pledged target.
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How can reducing methane improve health?
Methane can cause ground-level ozone, which can cause many respiratory problems, including childhood asthma, respiratory infections and chronic obstructive pulmonary disease. There is strong evidence that it can also exacerbate cardiovascular disease.
Methane and ozone are also greenhouse gases that cause global warming, which poses more health risks, especially through high temperature exposure.
We studied medical research and modeling and used it to find out what is at stake. We found that for every 1 million tons of methane emitted, approximately 1,430 people die prematurely, approximately 4,000 asthma-related emergencies, and 300 million working hours are lost due to health effects. With this in mind, human activities release about 370 million tons of methane each year.
If you reduce methane emissions in 2022, you will see the ozone response in 2022, and you will have to wait until the climate system is adjusted for at least ten years before you can see the climate impact.
What caused methane emissions to rise so fast?
Global emissions are rising. This is easily measured by chemical sampling of the air, and satellites can monitor large methane sources. But which sources are the most responsible is a more difficult question.
About 15 to 20 years ago, global methane emissions were fairly stable, and then began to rise gradually. Now, especially in the past five years or so, they have been rising rapidly.
Some studies point to the rise of hydraulic fracturing, which rapidly expanded natural gas production, roughly paralleling the recent increase in methane. Others say that livestock and the growing global demand for meat have played an important role. Some people have pointed to natural resources—especially wetlands in tropical regions that cope with climate change.
The most likely scenario is that it is a combination of all three.
The bottom line is that overall methane emissions must be reduced to slow climate change. If the increase comes from fossil fuels, waste or livestock, then countries need to find human resources. If it comes from a natural system that responds to climate change, they still have to find those human sources of methane. Reducing methane emissions is the strongest lever to mitigate these feedbacks.
If reducing methane pays off and the technology exists, why not do more?
The oil and gas industry itself is divided on methane. Many large companies supported the US methane emission rules set by the Obama administration — later overthrown by the Trump administration — because they knew it was worthwhile to capture methane. This is not a heavy economic burden for them, and supporting it can improve the image of the industry.
However, for small operators, the upfront cost of equipment and the need to hire labor to inspect the pipeline may be more difficult.
For example, if a company wants to repair a pipeline, it can shut down a section, install a compressor, and then pump all the excess gas under the pipeline further away before starting the repair. To do this requires obtaining a compressor, allowing trucks to move it, and employees to maintain it. Many studies have found that these investments can pay for themselves within a few years due to the value of the saved methane. But many small operators find it easier to vent the gas into the atmosphere when they want to work on the pipeline.
Similar problems exist in landfills and waste. When organic matter such as food waste decomposes, methane is released. Many landfills in developed countries have collected some methane gas. But many developing countries do not manage landfills or even collect garbage, so they cannot capture biogas.
In addition to technical solutions, our report also lists some recommendations that can be used in landfills everywhere, including better waste sorting, keeping organic materials away from landfills, and instead used for composting, and Reduce food waste in general. This can also reduce hunger if unused food is collected and distributed.
Agriculture also has some simple solutions. For many people, a healthy diet means reducing excess red meat, which can greatly help reduce the number of livestock slaughtered. These types of health and food safety programs can reduce total methane by far beyond the 30% target. Encouraging changes in food consumption may be politically risky, but it is a huge source of emissions. We will not keep the temperature below 1.5 C without processing.
Read more: 4 strategies to achieve global breakthroughs in energy and climate change
This is an updated version of the article originally published on May 6, 2021.