As CO2 only accounts for about a third of our influence on the climate, it is fair to wonder if going after the other 67% might be a more effective use of our resources.
Certainly in the short term we would get a better bang for our buck by going after black soot, deforestation… and methane.
Methane is about 23 times more potent as a greenhouse gas than CO2,so eliminating one tonne of methane from the atmosphere is equivalent to drawing down 23 tonnes of the more familiar bogeyman.
Here is a chart showing the sources of human generated methane in the U.S.
All of these sources are amenable to human mitigation.
For example, the U.S. EPA has this to say about methane leaks from natural gas operations: https://www3.epa.gov/gasstar/methaneemissions/ (They go into great detail, much of which concerns using correct and modern equipment.)
Good Housekeeping has this advice for farmers: “Anaerobic “digesters” utilize microorganisms to decompose cattle manure within a huge container. The resulting biogas can be harvested and used for “free” electricity production, rather than be expelled into the atmosphere.”
The EPA has more advice along the same lines:
“Trash decomposes (or rots) in landfills, creating methane gas. Methane rises to the top of the landfill and is collected in pipes. The methane is burned to produce heat or generate electricity.”
They cite some examples of this in use:
- Putting waste to good use. More than 500 landfill–to–energy projects are currently operating in the United States, and another 500 landfills are good candidates for turning their methane into an energy resource, which would produce enough electricity to power nearly 688,000 homes across the nation.
- Top producer. In 2009, Germany produced enough electricity from biogas to power 3.5 million homes.
- A world first! Sweden has been operating a biogas-powered train since 2005. It shuttles passengers between two cities that are 75 miles apart.
Sadly, environmentalists often oppose capturing methane for energy as it ‘takes the pressure off of people to reduce, reuse and recycle…” Sigh.
Methane often comes out of the ground during oil drilling operations. It is often burnt as it does so. But it can be captured and used as fuel.
The Obama administration has put in place a plan to reduce methane escape from oil drilling and operations by 40% to 45% by 2025. Secretary of Labor Jewell said “I think most people would agree that we should be using our nation’s natural gas to power our economy – not wasting it by venting and flaring it into the atmosphere,” said Secretary Jewell. “We need to modernize decades-old standards to reflect existing technologies so that we can cut down on harmful methane emissions and use this captured natural gas to generate power and provide a return to taxpayers, tribes and states for this public resource.”
Manure management accounts for about 12% of the total greenhouse gas emissions from the Agriculture sector in the United States. Greenhouse gas emissions from agriculture have increased by approximately 17% since 1990. One driver for this increase has been the 54% growth in combined CH4 and N2O emissions from livestock manure management systems, reflecting the increased use of emission-intensive liquid systems over this time period.
This too can be reduced. The EPA suggests:
- Handling manure as a solid or depositing it on pasture rather than storing it in a liquid-based system such as a lagoon. This would likely reduce CH4 emissions but may increase N2O emissions.
- Storing manure in anaerobic containment areas to maximize CH4 production and then capturing the CH4to use as an energy substitute for fossil fuels.
- For more information see EPA’s AgSTAR Program, a voluntary outreach and education program that promotes recovery and use of methane from animal manure.
Enteric Fermentation means the infamous cow belches–ruminant animals produce methane as they digest and they burp it out (they don’t fart it out–that’s a myth.)
“Methods to mitigate enteric fermentation emissions are still in development and need further research, but early studies looking at potential mitigation options have yielded some promising results. Most research has focused on manipulating animal diet in an effort to inhibit a rumen environment favorable to methanogens. Diet manipulation can abate methane by decreasing the fermentation of organic matter in the rumen, allowing for greater digestion in the intestines—where less enteric fermentation takes place. This inhibits methanogens and limits the amount of hydrogen (H) available for methane (CH4).”
All of these actions have appropriate technologies designed and available for use. Methane produces (apparently) about one third the effect on our climate as does our emissions of CO2.
Why would we ignore this opportunity? We can use it as natural gas to produce heat and electricity and lower our impact on the planet.