How Methane Capture Carbon Offsets Stack Up Against Other Carbon Credits

By Samson Opanda | Updated on September 14, 2021

Carbon offset programs are becoming more popular as nations globally collaborate to combat climate change. Not only is the current carbon trading market an established enterprise; moreover, global organizations are coming up with other offsets credits to compete with the current ones, with a view of reducing global emissions.

One such competing program is the methane capture carbon offset, which reduces greenhouse gas (GHG) emissions by removing methane (CH4) from the atmosphere. Unlike carbon offsets, which have a wide scope and concentrate on carbon dioxide reduction, methane offset projects focus exclusively on reducing the volumes of harmful methane gas in the atmosphere.

This begs the question, how do methane offsets compare to other carbon credits?

A 8 Billion Trees graphic showing the activities that emits methane gas in the US.

What Are Methane Capture Carbon Offsets?

Carbon dioxide (CO2) has taken center stage in the climate fight, but methane actually has a much greater warming impact than CO2 over a period of time.9 This means that while focusing on carbon dioxide is great for the near future of the planet, people must also direct their attention to this sneaky gas if the goal is to save the Earth from climate change.

Methane gas is a colorless, tasteless, and odorless hydrocarbon consisting of a single carbon atom bound to four hydrogen atoms. This gas is produced from natural and anthropogenic sources, with the latter accounting for 60 percent of the current global concentration of methane.3

Wetlands and wildfires are some of the gas’ natural sources, while anthropogenic sources include agricultural activities, coal mining, and wastewater treatment.

According to the U.S. Environmental Protection Agency (EPA), the largest portions of human-caused methane emissions come from:9

  • Agriculture, particularly the meat industry
  • Energy and industry
  • Waste from homes and businesses, including landfill waste

Within scientific circles, methane in the earth’s atmosphere is often described using the methane cycle, which begins in the soil when methanogens, methane generating microbes, release the gas.8 In the next phase, methanotrophs, micro-organisms that feed on methane, consume the gas in the soil.

Unfortunately, the production rate of methane gas in the soil is faster than its consumption, leading to leakages into the atmosphere where naturally existing methane combines with methane from other sources such as landfills, leading to its global concentration.4

Once released into the atmosphere, the gas has a lifespan of about 12 years, far less than that of carbon dioxide, which stays around for over a century.6 Important to note, however, is that despite its low life span, methane has a higher potency than carbon dioxide.

Methane is also a greenhouse gas. Accounting for 20 percent of global emissions, methane is the second most abundant greenhouse gas after carbon dioxide.2 Like other greenhouse gasses, methane traps infrared radiation and retains it within the earth’s atmosphere, leading to global warming.

So effective is methane at capturing and retaining solar radiation, that scientific sources place its potency at about 25 times that of carbon dioxide over a 100-year lifecycle.4 The natural process of removing the gas from the earth’s atmosphere happens in the troposphere through the oxidation of hydroxyl radicals.

These radicals are referred to as “sinks” because they break down pollutants such as methane, removing them from the earth’s atmosphere. In an ideal world, the capacity of naturally occurring sinks to eliminate methane would balance out its rate of generation from natural and anthropogenic sources.

Unfortunately, the present natural capacity of sinks is much lower than the rate of production of the gas, mainly due to human activities, which have doubled the concentration of methane in the earth’s atmosphere over the past two centuries.10

If unchecked, this trend will lead to high levels of global warming. Fortunately, the high potency of the gas also makes an excellent target for interventions, considering its reduction from the earth’s atmosphere is likely to reduce atmospheric warming significantly.

A view of a cliff while it rains at the Sequoia National Park, with 8 Billion Trees watermark.

How Do Methane Capture Carbon Offsets Work?

The immense potential of reducing global warming through methane reduction has led to numerous offsetting activities targeting the gas.

These activities, termed methane capture offsets, aim at reducing the concentration of methane gas by adopting a range of technologies that burn or use the gas, thereby removing it from the earth’s atmosphere.2

Burning the gas entails combusting it into less potent molecules such as carbon dioxide and water. Such projects mostly happen around landfills or coal mines, where methane gas is directly combusted into other molecules. On the other hand, using the gas entails adopting it for productive purposes such as heating water or electricity generation.

The latter, in particular, has been gaining traction over the past few years, thanks to technologies such as anaerobic digesters that break down methane gas, releasing electric power in the process.5

Such methane offsets are lauded for one main advantage – unlike other offset projects, methane capture projects are relatively easy to establish additionality.7 The term “additionality” here refers to the ability to determine the benefits of the projects from an established baseline.

Are There Drawbacks to Methane Capture?

Merits aside, methane capture offset projects do have their fair share of weaknesses.

First, the popularity of methane offsets credits may disincentivize activities that can directly reduce emissions.7 Direct activities, such as regulating agricultural emissions, are the surest way to reduce greenhouse emissions. As such, to the extent possible, they should take priority over using offset credits.

Unfortunately, given the attractiveness and success of methane offsets, emitting companies may opt to procure offset credits instead of reducing emissions. Secondly and perhaps more importantly, methane offset projects do not have a good track record of delivering the intended benefits.

According to the Stockholm Environment Institute, Clean Development Mechanism (CDM) methane landfill offset projects realize a paltry 35 percent of their projected emission reduction.7 The poor performance of some methane offset projects has led them to be dubbed “greenwashing projects” in the sense that they promise more than they deliver.

Carbon Offsets as an Alternative

Granted the weaknesses, offset traders can opt for other alternatives, such as carbon credits that produce direct benefits.

Carbon Capture and Storage (CCS) projects, for example, directly remove carbon dioxide from the atmosphere by storing it in abandoned reservoirs and mines, or even saline aquifers.7 Compared to methane capture projects, CCS projects have a higher chance of delivering intended benefits.

The projects, however, run the risk of leakages where some of the stored gasses can find their way back into the atmosphere. They also do not have co-benefits, making them unattractive to stakeholders’ keen on making a bigger difference.7

A more viable alternative to CCS that can address the mentioned weaknesses are forestry carbon offset projects.

Reforestation projects eliminate emissions either by conserving carbon sinks or through carbon storage. The projects realize the first goal through activities such as minimizing forest degradation, thereby protecting carbon sinks. Carbon storage, on the other hand, is achieved when previously unforested land is forested.

Compared to methane capture projects, reforestation offsets have a higher probability of delivering emission reduction targets. Moreover, the projects have a wide range of ecosystem and social co-benefits.1

Some of these ecosystem benefits include:

  • restoring plant and animal habitats
  • protecting indigenous species
  • promoting biodiversity

Social benefits include creating employment and livelihood opportunities through agroforestry or promoting food security by improving the water cycle.

A top view of a flowing river surrounded by trees in the Great Smoky Mountains National Park with an 8 Billion Trees watermark.

Using Methane Capture Credits and Carbon Offset Credits to Heal the Planet

Methane, as a greenhouse gas with a lower lifespan but a higher potency than carbon dioxide, deserves attention in the fight against global warming. In the current carbon trading market, the gas is offset using methane capture offsets.

Unfortunately, these offsets have notable weaknesses, such as having a lower chance of success when compared to Carbon Capture and Storage (CCS) Offset projects. CCS projects, on the other hand, do not carry co-benefits.

For traders keen on avoiding these challenges, reforestation offset projects offer a better alternative. These projects successfully sequester greenhouse gasses back into the soil, while delivering additional social and ecosystem benefits.

To start getting involved with these beneficial initiatives, one can begin by carbon offset tree planting and checking out the best carbon offset programs out there for offsetting GHG emissions.


References

1Di Sacco, A., Hardwick, K. A., Blakesley, D., Brancalion, P. H., Breman, E., Cecilio Rebola, L., Chomba, S., Dixon, K., Elliott, S., Ruyonga, G., Shaw, K., Smith, P., Smith, R. J., & Antonelli, A. (2021). Ten golden rules for reforestation to optimize carbon sequestration, biodiversity recovery and livelihood benefits. Global Change Biology, 27(7), 1328-1348. https://doi.org/10.1111/gcb.15498

2EPA. (2021). Importance of Methane. United States Environmental Protection Agency. https://www.epa.gov/gmi/importance-methane#

3National Academies of Sciences; Engineering; and Medicine. (2018). Improving characterization of anthropogenic methane emissions in the United States. National Academies Press.

4NOAA. (2020). Critical Thinking Activity – The methane cycle. NOAA ESRL Global Monitoring Laboratory. https://gml.noaa.gov/education/info_activities/pdfs/CTA_the_methane_cycle.pdf

5Park, J., Lee, B., Tian, D., & Jun, H. (2018). Bioelectrochemical enhancement of methane production from highly concentrated food waste in a combined anaerobic digester and microbial electrolysis cell. Bioresource Technology, 247, 226-233. https://doi.org/10.1016/j.biortech.2017.09.021

6Schiermeier, Q. (2021). Global methane levels soar to record high. Nature.com. https://www.nature.com/articles/d41586-020-02116-8#:~:text=Methane’s%20atmospheric%20lifetime%20%E2%80%94%20around%2012,2%20as%20a%20greenhouse%20gas

7Stockholm Environment Institute. (2020, December 29). Forestry & agriculture. Carbon Offset Guide. https://www.offsetguide.org/avoiding-low-quality-offsets/vetting-offset-projects/forestry-agriculture/