Gas emits so little CO2 compared to coal that it actually accounted for ONE THIRD of the drop in U.S. emissions from 2005 - 2016: https://www.carbonbrief.org/analysis-why-us-carbon-emissions....
That's a myth based on old data, no one who understands the models makes such simplified black and white claims. Methane (which is natural gas) is a much worse greenhouse gas than CO2. As in up to 100x the warming potential in the first couple of years until it's naturally converted. When burned, it's turned into CO2 but the problem is there is leakage all over the place because methane is volatile. During production, during transportation, during storage - it gets leaked into the atmosphere all over the place. See this more recent article:
https://www.iea.org/news/methane-emissions-from-the-energy-s...
As others have pointed out the title has been blatantly edited to omit the gas part. This is propaganda, declaring fossil fuel to be renewable energy doesn't make it so. Words still have meaning and the laws of physics still exist. It's really sad to see this sort of political science denial finds its way into HN now.
As parent notes, every molecule of methane burned turns into a molecule of CO2.
Incidentally: I don't see how burning coal produces more CO2 than burning methane. Burning coal is worse than burning methane because burning coal produces lots of particulates, as well as nitric and sulphuric acids. Same for burning oil.
Has anyone ever done testing on automobile exhaust similar to the testing that has been done on cigarette smoke? Of course not - nobody pretends that autombile exhaust is safe to inhale. Everyone knows it's much more carconogenic than ciggie smoke.
So I'm not defending coal and oil; they're worse than methane. Just not because they produce more CO2.
The issue is, all extracted methane isn't burned, and that's where the trouble starts. Over the past years, we've seen estimates for how much of it is lost into the atmosphere grow and grow. Some recent studies already claim more than 3%: https://www.scientificamerican.com/article/methane-leaks-era...
There has recently even been speculation that gas from certain sources where monitoring and environmental regulations aren't very strong could actually be worse than black coal. The truth is we don't really know this for sure yet.
You're right about the pollution, this and some other considerations are important as well. In certain countries air pollution is a serious issue. Germany doesn't really have this problem and the German plants have good filters. Germany has it's own coal, gas has to be imported. They're experiencing the effects of a dependency on foreign gas as we speak. So in the end, they might have actually better kept their coal power. I doubt it's going to happen though, coal is dead for purely political reasons. It's simply extremely unpopular.
This is just politics redacting facts... because they want the votes.
These "neo-green policits" could perfectly say "we are green but we acknowledge but we need grey energy for a while". They chose redefining language, as always.
(Cf. Victor Klemperer, "The language of the third reich" and also, as always, Orwell... "good is bad, bad is good" and "the past can be changed").
Red energy sources are the ones we immediately need to stop using: coal and oil.
Yellow energy sources are the ones we should stop using only if we can safely do so, but if we can't (and we can't, right now) we should continue using them: gas and nuclear.
Green energy sources are where we really need to go.
At a molecular level this doesn't make sense to me. The fundamental carbon cycle value proposition is to harvest energy released when a carbon atom (re)joins two oxygens. For the same energy, how would methane and coal produce different amounts of CO2?
That said, I can see how the oxygen reaction would be less efficient and create more byproducts (i.e. acid rain) using coal given its less refined nature. How methane would have a better energy to CO2 ratio doesn't seem to have an obvious mechanism.
https://en.wikipedia.org/wiki/Coal
https://en.wikipedia.org/wiki/Methane
Imagination, Physics, Fire & Trees - Richard Feynman (aka Trees grow from air, carbon cycle): https://www.youtube.com/watch?v=DJLMysTpwhg
Gas: CH4 + 2O2 -> CO2 + 2H2O
I don't know off hand exactly how many joules of energy (heat) are produced per mole in each case but it's not surprising that gas gives more joules per mole of CO2: it's a bit like you're burning hydrogen at the same time.
EDIT: It's relevant that O-H bonds are stronger than C-H bonds, presumably.
Water...
We're in trouble when 100% green energy is not enough.