Trump’s Swamp Gas (Methane) Emissions
Trump’s EPA and other agency swamp is full of industry representatives. They are there to eliminate regulations, and give a small profit to the industries affected, before they get sued out of existence for greed. Such is the extreme case of having the EPA self-decide that methane (natural gas or part of swamp gas) shouldn’t be regulated at all, despite the fact that it is 10% of US Greenhouse gas emissions. The total of methane in the atmosphere gives about 1/3 the climate forcing as the total of CO2 does.
The LA Times has an editorial today with the figures: the $280 billion a year industry would only save $17 to $19 million a year from cost to detect and contain methane. That is, at $18 million midpoint,0.064%. Trump is supposedly worth $3 billion. The cost is only 0.6% of Trump’s worth. Trump is supposed to have run up $120 million on his golf trips. That is only 15% of his golfing trips. The $18 million is 60% of the NRA election year funding of $30 million for his election. The cost would only build 3/4 of a mile of the Trump border wall, according to OMB cost estimates. What is involved, is simply using better valves, and detectors.
All of us are in fact equipped with natural gas detectors for leaks in our homes. Our home natural gas is infused with Mercaptan, a very smelly gas that contains sulfur.
Usually, excess methane at an oil or gas sight can just be burned. The CH4 burns with atmospheric oxygen to one CO2 molecule, and two H2O molecules. Since the commonly used numbers are that methane is 84 times more of a greenhouse gas than CO2 over 20 years, or 34 times more over 100 years, just converting it to CO2 is a great advantage. Low hanging fruit. The above numbers are per unit weight for each, and is not a useful measure, as we showed five years ago.
The problem, is that Obama extended the regulations such that all methane be collected and used for generating power. That is really high hanging fruit, for very little advantage.
I know that rigorous environmental groups want the complete elimination of all carbon based fuels, but natural gas can be turned on and off rapidly in power plants, to allow us to use up to 60% low cost renewables without CO2 emissions.
Since burning coal mainly gives one CO2 molecule per each Carbon atom, methane CH4 burning happens to give twice as much energy for each carbon atom, by burning the Hydrogen H atoms as well. That automatically gives half the emissions for the same energy in a natural gas plant. However, most coal plants are old and single cycle of steam generation. Modern combined cycle double generator natural gas plants, or that that also heat water with leftover heat, can get the emissions below 40% of an old coal plant. US coal plants are rapidly getting replaced by cheaper natural gas, which, again, are an aid to using fluctuating renewable energy.
Unfortunately, coal plants are being built worldwide, by countries that don’t have developed natural gas industries. So, in fighting climate change, producing natural gas and shipping it worldwide is not a sin, since it replaces much dirtier coal, and aids development of renewable energy.
But in all cases, the use of natural gas has to be leak free, because of its extreme greenhouse effects. Trump’s actions in not regulating this, by what we consider to be the world’s greatest and most scientific economy, is not only nonsense, but it should essentially be considered a criminal offense.
The leading oil and natural gas companies are all in favor of keeping the leak regulations. The problem is, there are an estimated 50,000 small companies involved the fracking industry. Goodwill among these anonymous companies cannot be relied on, and federal regulations and rigorous enforcement is a necessity. Trump is actually risking the currently needed industry, since conscientious states will be able to ban fracking. Of course, in some of the states where most natural gas comes from, they are dominated by oil and gas interests. The have weak laws, and without enforcement.
Methane has increased 2.5 times since pre-industrial times, from 772 ppb (parts per billion) to 1866 ppb. This is quite an increase, since the half life of methane is only about 7 years!
Now for the ratios of Methane to CO2 greenhouse gas effects by specifying a period for comparison. For CO2, the lifetime used is on the order of about 100 years. (It is true, that if we rapidly burn up all fossil fuels in 250 years, we will saturate the oceans, and the lifetime will go up to 4,000 years. To use this value when we are working hard to lower emissions, is really misleading, but you hear it.) If steady emission of methane was compared to CO2 over 20 years, by which time some of the methane is absorbed, the factor is 84. If you summed over 100 years, the ratio is about 24, but adding secondary aerosol interactions, it increases to 34, by weight. However, when you compare them by molecule, which is what is used for energy, the factor is reduced to 12.
I have seen 9, 12, and 14 years as estimates of the lifetime of CH4 in the atmosphere. It is converted to CO2 by reaction with atmospheric OH radicals. The lifetime is the time by which the concentration has fallen to 1/e its amount, where e = 2.718, so about 1/3 of its initial amount.
But here is the problem: you don’t stop emitting methane unless you capture it and burn it. We will need it for several years for balancing fluctuating renewables. If you keep leaking it every year, it goes back to the 140 number. We will also keep emitting CO2 for a while. Used properly for energy generation, with no leaks, one CH4 molecule still only gives one CO2 molecule, or a ratio of 1.
Considering the efficiency of modern CH4 plants, I showed five years ago that if you leak one out of every 5 CH4 molecules that you burn for power, you break even in converting from coal to natural gas power.
There are other sources of methane, of course. Cows and sheep generate it, although for cows, a lot of it can be captured and used for energy generation. Beef use is growing. Methane also occurs in rice growing. The use of cow pies for heating and cooking in poor rural areas is a serious health hazard, and can be replaced by fuel or electricity with development. The possible tipping point of where deep water and permafrost trap methane and its release with warming has to be avoided.
Hopefully, the legal requirement that regulations be based on the best available science, will also triumph in the necessity of stopping methane leaks. But to update Bob Dylan: But the courts, they are a changing.
For completeness, here are the US Greenhouse Gas emissions as CO2 equivalent: CO2 82%; CH4 10%; 6% Nitrous Oxide; and 3% Flouridated gases.
The US sources are: 29% Transportation; 28% Electricity; 22% Industry; 12% Commercial and Residential; and 9% Agriculture.
World Greenhouse Gas emissions in CO2 equivalent from IPCC (2014) are: 65% CO2 from fossil fuels and industries; 16% Methane; 11% CO2 from Forestry and other land use; 6% Nitrous Oxide; and 2% from Flourinated gases.
Here are the worldwide sources of methane. 19% of emissions are from Coal, Oil, and Natural gas. A lot of the other sources can be mitigated, and used to achieve Zero emission goals, without getting to 100% renewables.
The United States is only fourth in the list of world emitters. Unfortunately, the data I found at IndexMundi is from 2012. China leads with 1,752 megatons (metric) of CO2 equivalent, India is second with 636, then Russia with 546, the US with 500, and Brazil with 477. The world total methane emissions in 2012 were 8,000 megatons of CO2 equivalent. So the US emissions were 6.3% of world emissions. China’s emissions were 22%. In 2020, world methane emissions are estimated to be 9,390 megatons of CO2 equivalent.
The leak rate of US natural gas production is estimated at 2.3% of natural gas production. It is estimated that half of the fugitive gas comes from just the top 5% of leaks. The Environmental Defense Fund is planning to launch its own satellite, MethaneSAT, to find the regions of most leakage, perhaps by 2023. I suggest that Mercaptan be injected with fracking fluids. The International Energy Agency estimates that as much as 50% of oil and gas leaks can be fixed at zero net cost.
The EPA website links to voluntary management programs, not laws.
Technical Note: The ratio of CO2 equivalent emissions over time t, R(t), is proportional to the starting ratio R(0) as:
R(t) = R(0) (T1/T2) (1-e^(-t/T1))/(1-e^(-t/T2)),
where T1 and T2 are the atmospheric lifetimes of the compared greenhouse gases. For long times t compared to the lifetimes, this reduces to the simple result:
R(t) = R(0) (T1/T2).
If T1 is methane with around a 10 year lifetime, and T2 is CO2, with around a 100 year lifetime, the (T1/T2) factor is 1/10. That is before aerosol adjustments. Both effective lifetimes seem to have large uncertainties. When t is 20 years or 100 years, the extra exponential factors do modify the ratios somewhat.
