Within climate solutions, direct methane capture from water should sit alongside carbon dioxide removal.
Carbon dioxide removal is a process of removing carbon dioxide directly from the air to stop it contributing to global warming. Although quite a new industry, it is the most mainstream approach to carbon removal and one that Bluemethane is often compared to.
However, when we examine the science, we see that alongside directly capturing carbon dioxide from the air, climate solutions need to also remove methane from water. We argue that investment needs to shift its balance towards direct methane capture. And this is why….
To start with, a few definitions
- CH4: Methane (very similar to natural gas)
- CDR: Carbon dioxide removal
- Emissions Avoidance: “The most effective carbon management strategy over a multi-decadal timescale to achieve atmospheric CO2 stabilisation and a subsequent decline” [1]
- Emissions Removal: The process of removing carbon dioxide from the atmosphere and locking it away for decades, centuries, or millennia. This could slow, limit, or even reverse climate change. [2]
- Global Warming Potential (GWP) [3]: A metric to compare the warming potential of different greenhouse gases.
- Calorific power: A measure of the energy content of a given substance.
Removing methane from water seems to make sense:
- Methane has a GWP of 34x in a 100-year timeframe or 85x in a 20-year timeframe. In other words, every molecule of methane removed or avoided is at least 34 times more effective in reducing global warming than a removed or avoided molecule of CO2.
- Most CO2 from reservoirs is natural (it would have occurred anyway)….but most of methane from reservoirs is additional (anthropogenic, human made).
- With a calorific power of 55MJ/kg [4], methane is a valuable resource (can be used for energy or as feedstock for ammonia, hydrogen, and energy)…. whereas CO2 is mostly considered waste (ok, it can be used in fizzy drinks).
- CO2 is highly soluble water…but methane is “hydrophobic” (low solubility) which means that it’s literally “easier” to capture CH4 from water than CO2 from air.
- We need water reservoirs, whether for irrigation, drinking, or energy generation. We need to store and regulate water, especially in a climate changing world. Sure, there are a lot of things to improve but reservoirs are critical and will endure.
Our overall thinking:
Whilst we recognise the importance of direct carbon capture to remove past and present atmospheric greenhouse emissions, it is a bit like trying to mop the wet floor without turning off the the tap.
No matter how well-intentioned people or corporations want to be, we still need to reduce new emissions heading to the atmosphere.
Bluemethane removes methane from water to prevent its escape into the atmosphere. As a complimentary solution alongside carbon dioxide removal, this seems a good idea. Some might say it’s an 85 times better idea.
References:
[1] https://www.globalcarbonproject.org/carbonneutral/AvoidEmissions.htm
[2] https://www.american.edu/sis/centers/carbon-removal/what-it-is.cfm
[3] https://blogs.edf.org/climate411/2008/02/26/ghg_lifetimes/
[4] https://en.wikipedia.org/wiki/Heat_of_combustion
