The article mentions natural gas is mostly methane (CH4).
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...)
You have clearly misunderstood. I try to simplify: Methane is 4 H per 1 C, oil is approx. 2 H per 1 C. Burning the H-part produces just water, which is harmless. The bottom line is that burning methane gives only half the CO2 emissions, compared to burning oil, per energy produced.
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.)
Well, true, but the amount of water vapor in the atmosphere is determined by the balance of (i) water vapor condensing back to liquid water (e.g. rain), and (ii) water evaporating to atmosphere from oceans, lakes, soils and ecosystems. This balance is mostly determined by the temperature.
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.
> 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.
You should read the article. The issue is that CH4 is a vastly more powerful greenhouse gas than CO2, because of how strongly it absorbs IR [0]. Even small methane leaks are significant. This is counterbalanced by methane
* 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!
I'm not sure what you're getting at. The scientists explicitly mention the fact that burning methane produces CO2:
> 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.
Consumption by plants is mostly carbon neutral, since they release it again later. It looks like individual CO2 molecules survive in the atmosphere only about 5 years. But still if you put a pulse of CO2 into the atmosphere, the half life is 30 years and (since it isn't a simple exponential decay) even 100 years from now still 36% of it will be in the atmosphere. In contrast, it looks like methane is gone in 12 years.
Natural gas is often cited as a bridge to more renewable energy.
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.
We have enough uranium to satisfy our power needs for a few hundred thousand years. It's just that nuclear plants are expensive to build (and run) and electric cars aren't common yet.
Citation needed re enough Uranium. AFAIK: 1) whoever says anything about energy with thousands of years assumes that our energy needs aren't going to grow. The modern states, economies and populations however expect the growth as it was exactly what happened during the last 200 years. 2) There's a lot of U only if the one once used is reprocessed, howerver there are significant problems with reprocessing now.
most of the planet's uranium is in very low concentrations in the sea.
We certainly don't have enough commercially viable uranium (ie, that can be extracted and enriched with less energy inputs than they might produce) to maintain current rates of consumption for more than around 100 years using existing technologies.
That's not exactly true. It looks like the closer to first world a place gets, the less children. It looks like we will have a top off in population (barring a sudden loss caused by a big war).
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.
Come to the Barnett Shale, and see how it isn't good, either. You can't drink it, and we're losing our aquifers to contamination from drilling, fracking, and the waste water injection wells.
I call BS.
for rich developed nations, gas is an unnecessary and dangerous distraction from the genuine renewable and sustainable energy alternatives which are already taking shape around us.
there is an argument about using gas in the developing world (where they need cheap energy fast), but wealthy nations should be leapfrogging into the same renewable energy solutions that will inevitably dominate our futures, rather than 'investing' in new gas plants with their long 30-40 year lifespan.
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.
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...)