Two Climate Analysts Fault Gas Leaks, but Not as a Big Warming Threat
dotearth.blogs.nytimes.com
dotearth.blogs.nytimes.com
Here is the combustion reaction for burning methane:
CH4 + 2 O2 → CO2 + 2 H2O
Note right side of equation.
The "climate scientists" cited in the referenced article have confusion on this issue, as they contrast the effects of methane releases to those of CO2.
It's interesting to contemplate what has to occur for someone to adopt the title "scientist" and leading authority in a subject while remaining confused about freshman highschool chemistry.
Burning natural gas may release some incidental uncombusted methane, but the major gaseous combustion product is clearly CO2. An unlearned person reading these articles would not know that from the way methane emissions are presented as the relevant issue.
It's also interesting to see that methane has now been rehabilitated in some minds into a friendly and relatively clean emission after years of hysteria regarding the impending doom that is coming from cow flatulence; statements such as "A significant portion of [global greenhouse gas] emissions come from methane, which, in terms of its contribution to global warming, is 23 times more powerful than carbon dioxide." (http://www.newscientist.com/blogs/shortsharpscience/2013/03/..., http://science.howstuffworks.com/zoology/mammals/methane-cow...)
> If a methane molecule is burned, it produces one CO2 molecule.
> Methane produces about 2 times as much energy as does coal for the same CO2.
Perhaps the title on HN is a bad one, but the scientists are specifically arguing against the assertion that natural gas is even worse for the environment than coal because a large amount of it leaks into the atmosphere before it ever even has the chance to burn.
* Being less carbon-rich [than coal] -- looking at the right side of your equation, about half the energy comes from fusing hydrogen (H-O) as opposed to carbon (C=O) [1]
* Allowing more efficient combustion (Muller says 60% vs. 44%)
You cannot come to any conclusion here without doing the math!
[0] https://en.wikipedia.org/wiki/Global-warming_potential#Value...
[1] https://en.wikipedia.org/wiki/Standard_enthalpy_change_of_fo...
the short lifetime of methane as compared to CO2, which basically hangs around forever.
So what happens to the methane? (See the chemical equation above)
CO2 also does not necessarily "hang around" forever, it is consumed by plants for one thing.
There's much more detail in the 2007 IPCC report: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-10...
So in theory, burning methane to produce energy, would give only half the greenhouse gas emissions, compared to burning oil.
But, methane is 25 to 72 times more potent a greenhouse gas than CO2 [1], so even relatively small leakages during the production + transport + use of methane might be enough to spoil the advantage.
If methane has 25x larger global warming potential than CO2, then – even though methane is 2x more energy efficient – a mere 4% leakage would be enough the bring methane back to the level of CO2.
(I have no idea what are the typical leakage amounts in methane production, transport and use.)
[1] http://en.wikipedia.org/wiki/Greenhouse_gas#Global_warming_p...
So you can't really add much water to the atmosphere by only emitting water vapor by e.g. burning gas, or even boiling huge amounts of water, because the excess water vapor will just condense back to liquid water.
Also if we imagine some huge industrial process that dries the air, removes water vapor from the air, this wouldn't really decrease the amount of water vapor in the atmosphere, because the drier air would just suck up the water back when it next comes into contact with a water body, damp soil or vegetation.
That's true on the macroest of macro scales, but in local climates, water vapor doesn't maintain a steady state. Otherwise every climate would be relatively green. In any case, if it's really so much better to capture methane and burn it for fuel than let it escape, then we should be forcing natural gas companies to figure out how to capture melting methane clathrates instead of taking them out of ground wells where they're relatively stable.
"The real argument against over-reliance on fracking as a solution to the climate problem is that its value as a bridge fuel has been oversold."
It's like recommending to a smoker that they switch to chewing tobacco because it lowers their risk of dying from cancer.
> The modern states, economies and populations however
> expect the growth as it was exactly what happened during
> the last 200 years.
That's assuming there's no exponential growth in energy demand. Which there is.
Human population is growing exponentially. Technology is growing at least exponentially, probably faster.
And this is true in what circumstance? The world fertility rate is going down and in some countries, like Japan, the population is shrinking.
That's assuming there's no exponential growth in energy demand. Which there is.
Citation?
On a more serious note. I see the immediate future as a focus not only on cleaner energy production but also a more efficient and far reaching energy grid as in many places neither nuclear nor renewable energy production are feasible. Gas being cheaper and cleaner (ref. air pollution) is a sensible investment for those areas who are still relying on dirtier fossil-fuel powered energy production.
The thing about renewable energy like wind and solar is that it has sudden variability. To satisfy your needs with it, you need some other form of energy that can be ramped up and down just as quickly as a counterbalance. The obvious candidate would be batteries, but we do not have battery systems large enough to supply the grid for minutes at a time. (People are working on this. But we do not currently have it.)
This is where natural gas comes in. It produces lots of energy. And you can ramp energy production up and down very efficiently, almost instantaneously.
By contrast compare something like nuclear power. A nuclear power plant is basically a huge steam engine with the water heated by radioactivity. To start generating power you bring the water to a boil. To stop you let it cool down. But big tanks of water do not heat up or slow down fast - you need hours. Thus you can supply a grid from nuclear, but you can't counterbalance nuclear and renewables.
Therefore the common vision is that we move from a largely coal base to a mixed natural gas/renewable base, and then to a renewable/battery base. So natural gas is seen as a bridge to an all renewable future.
To limit global warming to 2°C we would need to leave 80% of already discovered hydrocarbon resources unused. This is same as producing CO2 at current level next 18 years and then stopping completely forever. We are already warmed +0.8°C and effects have been worse than expected.
To be realistic, there is no signs that we are even trying to reduce global CO2 emissions, we are just trying to slow down the increase. There is no sign in stock markets that all those hydrocarbons will be left into the ground. From developed nations only Germany is trying to leapfrog, but it might fail due to economic/political reasons when the cost becomes clear to voters (well see).
According to FAO, meat production causes 17% of global greenhouse gas emissions. That's more than traffic. If we would be serious, we would have to solve that ASAP. Nobody is even thinking doing that.
All actions in democratic countries are result of two forces: what people feel comfortable giving up and how much people fear global warming. People are not comfortable giving up anything even lightly significant even if they live in rich countries. There is not enough investments and technology is not advancing at the pace we would need to have to live comfortable life and saving the environment.
If you have kids, take them diving to see coral reefs. It's last time to see.
http://oceana.org/en/our-work/climate-energy/ocean-acidifica...