An engineering solution to climate change?

[dmp]

Just want to say I'm enjoying the Matador / RuffRecords discussion on this.
Reading with interest.

 

[ruffrecords]

So if I can paraphrase your argument correctly, you a) agree atmospheric CO2 concentration is increasing, yet b) the contribution of man is small, ergo, the increase must be due to something else?  In order to be true, there must be some 'carbon sink' that is not keeping up with the additional input, albeit through some natural process.  Which sink do you propose explains this?

That is not quite what I said  and your logic is flawed.

To paraphrase what I said, there are many large sinks and sources, most of which are poorly understood. We have only approximate data about how much they sink or source. The errors in these dwarf the contribution made by man. Ergo you cannot tell which one(s)  cause any observed increase.

To use your bath tub analogy, in real life the bath has several taps and several drains and mankind's contribution is the steady drip you mentioned. Nobody knows how much water comes out of each tap and how much goes out the drains. All you can measure is how much water is is the bath. If you observe a steady change in the level in the bath you cannot say for certain what causes it.

To put this into context, until recently, estimates of the CO2 yield of one of the world's best known land volcanoes, Kilauea Volcano (Hawaii) was 2,800 tonnes/day. In 2001 Gerlach and co-authors established by measurement a more accurate figure of 8,800 tonnes/day. This is a well studied volcano but still it is only recently that accurate figures have emerged. We know far less about submarine volcanoes. In 2006 a newly discovered seabed volcano southeast of Japan was found to be venting copious quantities of liquid carbon dioxide leading the researchers to comment "submarine arc volcanoes may play a larger role in oceanic carbon recycling than previously realised"

So nobody knows the exact contributions of these big sinks and sources and they know even less about what might cause them to change. That they have changed over geological time is beyond dispute. What causes them to change is unknown.

Cheers

Ian

 

[midwayfair]

You should cite your sources, Ian, particularly when you use a direct quote. You might also want to read Gerlach's own work addressing the statements you made:

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2011EO240001

(I'm not going to save anyone a click. The abstract is short, go read it.)

 

[dmp]

The real question you seem to want to avoid is where does all the carbon come from and go to? The atmosphere contains about 780 Gtonne of of carbon of which about 90Gtonne is exchanged each year with the oceans, and about 120Gtonne with plants. Thus about 25% of atmospheric carbon is tuned over every year. I addition the oceans have about39,000 Gtonne of carbon dissolved in them, some of which is sequestered each year in the formation of sea floor limestone. 70 million Gtonne of carbon has accrued cumulatively over geological time and soils, vegetation and humus contain another 2300 Gtonne.

In amongst these figures, the 7.8Gtonne produced by humans annually is tiny. On  estimate says it is a quarter of the  error in the estimate (32Gtonne) of the estimated carbon dioxide production from all other sources.

Cheers

Ian

So the human produced carbon that is converted from stored fossil fuel reserves into the atmosphere is 7.8Gtonne/year, or 78 Gtonne/decade, or 780 Gtonne/century?  How is that tiny? When you report the atmospheric amount is currently 780 Gtonne.
The fossil fuel carbon is a stored term in the equation - putting this into a system that was in equilibrium can be destabilizing (even if the exchange rates to ocean/plants is large) would you disagree?

 

[ruffrecords]

So the human produced carbon that is converted from stored fossil fuel reserves into the atmosphere is 7.8Gtonne/year, or 78 Gtonne/decade, or 780 Gtonne/century?  How is that tiny?

Compared to the nearly 200 Gtonne that is exchanged annually with plants and the oceans it is tiny. Everyone seems to think we are the only source of CO2. There are several sources and sinks for CO2, nearly all of them much bigger than man made CO2. There is no reason to think any of the other sources are constant nor that any of the sinks are saturated. We understand so little about these big sinks and sources that any one of them could be causing the observed increase in atmospheric CO2.  Any one of them could introduce a much bigger variation in atmospheric CO2 than human CO2 production. In fact the measured increase is only half the human CO2 output so at least 50% of it is being sunk somewhere.

When you report the atmospheric amount is currently 780 Gtonne.
The fossil fuel carbon is a stored term in the equation - putting this into a system that was in equilibrium can be destabilizing (even if the exchange rates to ocean/plants is large) would you disagree?

No, see above.

Edit: And that is even before we consider what effect atmospheric CO2 has on average global temperature (if any).

Cheers

Ian

 

[ruffrecords]

You should cite your sources, Ian, particularly when you use a direct quote. You might also want to read Gerlach's own work addressing the statements you made:

I think you may have missed my point which was that well studied sources, like volcanoes, are poorly estimated and the errors in estimation are large. The larger CO2 sources are much less well studied or understood and are consequently even less accurate in their estimates which makes working out what is actually causing atmospheric CO2 increases rather difficult and at best highly inaccurate.

Cheers

Ian

 

[JohnRoberts]

There is a shortage of CO2 in europe threatening the beer supply during the world cup...

This would make a great fake news item but I believe it's real.  Flat beer anyone?

JR

 

[boji]

The tobacco analogy to climate change is a particularly good one.

Thanks Matador, it's nice as your analogy, apart from making a case for something, was also itself instructive.

Also enjoying Ian's counterpoint; no dialectic, no synthesis!

 

[boji]

I found this interesting and wanted to share:

"Most systems to split water into its components -- hydrogen and oxygen -- require two catalysts, one to spur a reaction to separate the hydrogen and a second to produce oxygen. The new catalyst, made of iron and dinickel phosphides on commercially available nickel foam, performs both functions [at much lower current]."
https://www.sciencedaily.com/releases/2018/06/180629102602.htm

 

[ruffrecords]

I found this interesting and wanted to share:

"Most systems to split water into its components -- hydrogen and oxygen -- require two catalysts, one to spur a reaction to separate the hydrogen and a second to produce oxygen. The new catalyst, made of iron and dinickel phosphides on commercially available nickel foam, performs both functions [at much lower current]."
https://www.sciencedaily.com/releases/2018/06/180629102602.htm

Assuming the of conservation of energy is obeyed, the energy input into the separation process must be at least equal to the energy obtained by recombining them (burning). Which begs the question where does the splitting energy come from?

Cheers

Ian

 

[boji]

"Assuming the of conservation of energy is obeyed"

I didn't assume i/o unity or above unity or anything. But let's say it takes 2A to typically hydrolyze water at a given output (not sure what you really need) and this 'discovery' allows it to equally produce this at 500mA, that means one wind turbine just turned into 4. Not an outright solution, but a step in the right direction. I also hear fusion is getting more efficient too with recent tests.

 

[JohnRoberts]

I didn't assume i/o unity or above unity or anything. But let's say it takes 2A to typically hydrolyze water at a given output (not sure what you really need) and this 'discovery' allows it to equally produce this at 500mA, that means one wind turbine just turned into 4. Not an outright solution, but a step in the right direction. I also hear fusion is getting more efficient too with recent tests.

Back in 60s we used platinum catalysts for electrolysis (to break H2O + electricity into H2 and O2). (I recall my older brother making a fuel cell for his science fair project one year).

The article said better but not how much... and cheaper than platinum.

Hydrogen fuel cells (or even direct combustion) like EVs can remove pollution from dense population areas, but doesn't eliminate it, mainly just shifts it elsewhere.

JR 

 

[boji]

"hydrolyze water"  that's like saying goldify gold, isn't it.  :

Electrolyse, thanks JR.

 

[boji]

"EVs can remove pollution from dense population areas, but doesn't eliminate it, mainly just shifts it elsewhere. "

We couldn't scrub the water vehicle's exhaust with some fancy carbon catcher? (googlin' now).

 

[dmp]

Hydrogen fuel cells (or even direct combustion) like EVs can remove pollution from dense population areas, but doesn't eliminate it, mainly just shifts it elsewhere.

No, that's not true when electricity is generated from renewable sources, which is feasible now.

last year we bought a  2013 Nissan Leaf fully electric car. Installed a home charger. And our electric utility has a voluntary program to get all your electricity from wind & solar. So we pay $0.125/kwh which is a couple cents more than the standard electricity from natural gas.  Cost per mile is still half that of gasoline.
The leaf's main limitation is range, but current EVs, like the chevy bolt, have comparable range to ICE cars. Used Leafs are pretty cheap and as our second car for commuting in the city it works great.

But the adoption of EV or fuel cell vehicles needs to go hand-in-hand with the adoption of renewable energy powerplants.

Assuming the of conservation of energy is obeyed, the energy input into the separation process must be at least equal to the energy obtained by recombining them (burning). Which begs the question where does the splitting energy come from?
Cheers
Ian

The input energy is going to be greater than the energy content of the fuel you produce. It actually can't even be equal or it would be a completely reversible process (2nd law of thermodynamics).
And unless it comes from non-fossil fuel sources doesn't make much sense for generating fuel.
I did see a summary of a research project recently that was using a solid oxide fuel cell followed by an engine to generate electricity from natural gas with ~70% efficiency, which is higher than current methods.

The conservation of energy has not been found to be wrong yet. That is the only proof of the 1st & 2nd law, by the way. They have never been found to not be true.

We couldn't scrub the water vehicle's exhaust with some fancy carbon catcher? (googlin' now).

A fuel cell vehicle uses hydrogen as fuel so the reaction is H2+O2 -> H2O
They don't have an carbon as an emission, just water.

 

[ruffrecords]

But the adoption of EV or fuel cell vehicles needs to go hand-in-hand with the adoption of renewable energy powerplants.

The other factor that is important for EV is the energy density of the energy cell (fuel cell or battery). I have no idea how fuel cells compare with current battery technology.

Another factor is weight. Steel cars are heavy. Plastics make them lighter but we don't want to be making more plastic. Aluminium is light also but needs inordinate amounts of energy to produce it.

I understand petroleum is still the most energy dense readily available fuel.

Cheers

Ian

 

[dmp]

The other factor that is important for EV is the energy density of the energy cell (fuel cell or battery). I have no idea how fuel cells compare with current battery technology.
Another factor is weight. Steel cars are heavy. Plastics make them lighter but we don't want to be making more plastic. Aluminium is light also but needs inordinate amounts of energy to produce it.
I understand petroleum is still the most energy dense readily available fuel.
Cheers
Ian

The Nissan Leaf has a 24 kwh battery that weighs about 170 kg (I think). The Chevy bolt has a 60 kwh that weighs 440 kg (I think).
By comparison 10 gallons of gasoline at a heating value of 45,000 kJ/kg and density of 703 kg/m^3, weighs 27 kg and has 332 kwh of chemical energy. Assume a 30% conversion efficiency and you have 100 kwh of available energy.

So gasoline has 100kwh/27 kg and the battery has 24kwh/170kg. The kwh/kg available energy is about 27 times higher for gasoline versus batteries.

But gasoline is  not the most energy dense fuel in comparison to Uranium or other nuclear materials

 

[dmp]

Energy density cartoon...

 

[bluebird]

Lol!

 

[boji]

"A fuel cell vehicle uses hydrogen as fuel so the reaction is H2+O2 -> H2O"
They don't have an carbon as an emission, just water.

Brain hiccup. You're right.  And I knew this from years ago, but JR had me wondering where the offset is coming from...
For hydrogen to presently supplant petro demand we would need to mostly make it out of fossil fuels. That and it has low levels of efficiency during combustion relative to petrol.  Also hydrogen-powered cars do appear to emit more than just water, (nitrogen dioxide). How or how much I can't say.