Friday, August 30, 2019

Methane 101

Click for photo credit.
Methane is in the news due to the fact that the current EPA administration is deregulating methane rules that help to keep it from entering the atmosphere during its extraction, shipping, and storage. Given this, I thought I would provide some basic background on methane so that readers of On the Brink understand the significance of the regulatory rollback.

Methane is a very basic organic molecule (CH4) that is found underground and in the atmosphere. There are many ways it can form, but the two most common ways are through geologic and biologic processes. Methane forms geologically in similar fashion to coal or petroleum and is associated with these types of deposits. Indeed, in some areas, methane is burned as a waste product when oil is extracted. Biologically, methane can form in the stomachs of animals and from the decomposition of organic matter in places like wetlands. Thus, methane releases from cattle and rice fields are large contributors to the atmosphere. In the U.S. cattle account for about a quarter of the anthropogenic methane released into the atmosphere.

Methane concentrations at the Mauna Loa Observatory.
Click for image credit.
The concentration of methane in the atmosphere has been increasing steadily for the last two centuries. The atmospheric observatory in Mauna Loa, Hawaii, keeps track of atmospheric methane so you don't have to. The global monthly mean has increased about 13% from around 1650ppb (parts per billion) in the mid 1980's to 1860ppb today.

The increase in methane seems like it would not be a big deal given that methane makes up a very small percentage of the atmosphere. However, there is one big problem. Methane is a very potent greenhouse gas.

We all know that carbon dioxide is a greenhouse gas. However, there are many others. Greenhouse gases have the ability to absorb heat which means that they contribute to the heating of the atmosphere. However, not all molecules have the same ability to store heat. Some do a better job of it than others. We express this by creating a number called a carbon dioxide equivalent which is abbreviated as CO2e. Carbon dioxide has a CO2e of 1. Methane has a CO2e of 25. There are several other greenhouse gases that have even higher CO2e's such as nitrous oxide (298 CO2e) and sulfur hexafluoride (22,800 CO2e).

The fact that methane has a CO2e of 25 means that it is 25 times more potent of a greenhouse gas than carbon dioxide. This is why there has been such a push to regulate methane. We are trying to reduce one of the main drivers of climate change.

Climate change is releasing even more methane. As the Arctic areas warm, ancient frozen organic matter is decomposing and releasing methane as shown in the video above.

It is relatively hard, but not impossible, to manage much of the anthropogenic biologic methane. I won't go into details, but some possible solutions include changing feed stock, reducing herds, and changing rice production processes.

However, research has shown that huge amounts of methane are lost to the atmosphere during the extraction, shipping, and storage of methane. Overall, according to a recent study, leaks account for about 2.3% of all methane used. We've all smelled methane leaks. Sometimes these leaks lead to terrible explosions. To enhance safety and reduce leaks, the EPA published rules in 2016 that regulate methane emissions in the natural gas industry. These are the rules that the current administration is trying to eliminate. Energy companies, for the most part, are in favor of the rule and are against the rollback of the regulation. As I noted in an earlier blog post, many leaders of companies are trying to be much more focused on sustainability and climate change.

I am certain that the change in rule will be challenged by the public and by the industry. I suspect its implementation will be delayed until after the 2020 election. As all of us continue to see growing evidence of climate change all around us, the public is becoming less patient with the types of shenanigans that lead to greater emission of greenhouse gases.

No comments: