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China claims breakthrough in mining 'flammable ice'

bbc.com

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Re: China claims breakthrough in mining 'flammable ice'

#41

Post by mistermann »

badosu wrote: post #27
jvm wrote: post #21

Earlier quoted context omitted.

China is 175th in GDP per ton of emissions: https://en.wikipedia.org/wiki/List_of_countries_by_ratio_of_... US is 80th, not great but there's really no comparison to Chian. For rich country comparison, UK is 22nd and France is 9th.

> US is 80th, not great but there's really no comparison to Chian. This is true, but one should take into account that US's and most of the developed world economy has shifted into services and intellectual or branding schemes, exporting the dirty job of manufacturing to China. It would be really surprising if that was not the case.

Very good point, and considering China is basically the manufacturing arm of almost every western country, any list "ranking" countries is useless propaganda.

Well, not useless I guess, considering it is propaganda.

Re: China claims breakthrough in mining 'flammable ice'

#42

Post by philipkglass »

bildung wrote: post #28
aianus wrote: post #20

Earlier quoted context omitted.

> If you took a province of China with 200 million inhabitants, it would be an extremely responsible country compared to a country of similar size. Having such an enormous population and population density relative to Western countries is irresponsible. I don't agree that you can just divide by population and say they're fine.

> I don't agree that you can just divide by population and say they're fine. CO2 output per country is not a reasonable metric. If we just split China into its provinces, does that make the problem go away? After all, each of the new countries now has a pretty small CO2 output.

The sustainability of CO2 emissions is measured in terms of emissions sources divided by its emissions sinks. A ratio above 1.0 means long term increases in atmospheric and oceanic CO2. The further above 1.0 we are, the less sustainable.

To make a very crude approximation, terrestrial emissions sinks scale proportionally with area. (Slightly less crude: sinks scale with forested area.) Generally speaking, countries need to have low emissions per unit area to be sustainable. Having low emissions per-capita but a high population density is no more sustainable than low population density and high emissions per-capita.

China has land area of 9328246 km^2 and emitted 10641789000 tons of CO2 in 2015: that's 1141 tons/km^2/year

USA has 9147590 km^2 land area and emitted 5172338000 tons CO2: 565 tons/km^2/year

Canada has 9093507 km^2 land area and emitted 555401000 tons CO2: 61 tons/km^2/year

EDIT: this was not intended to show China as "the worst." Belgium, for example, emits 3324 tons/km^2/year.

On one hand this leads to philosophical issues of justice like "luck egalitarianism": is it fair that Canadians, by accident of birth, have so much more headroom to emit sustainably than people born to the south or east of them? (Is it fair that any nation's citizens enjoy advantages from their own country's natural resources? I tend to think "yes, it's fair enough" but people may reasonably disagree.)

On the other hand, the pragmatic issue is that most countries are emitting CO2 faster than their geographic area can sink those same emissions. Certainly the largest political blocs are emitting unsustainably. The object of measuring emissions is ultimately to control them, not just to identify the party that deserves the loudest booing while we wreck the climate together. The USA, China, India, EU: none of them is "fine" and all need to make significant progress before their emissions are balanced with their sinks. (Not all of the effort needs to be on abating sources, though that's where the low hanging fruit is right now. Increasing sinking rates with afforestation, promoting soil carbon stores, and/or silicate weathering are also viable options.)

Re: China claims breakthrough in mining 'flammable ice'

#44

Post by setr »

0xfaded wrote: post #39
ams6110 wrote: post #26

Earlier quoted context omitted.

Methane doesn't persist in the atmosphere for nearly as long however. It will break down upon exposure to oxygen, ozone, and UV sunlight.

The commonly cited 20-25 multiplier takes into account the half-life of methane. If the methane didn't beak down the multiplier would be 130-140.

why wouldn't you want to take the half life into account

Re: China claims breakthrough in mining 'flammable ice'

#45

Post by erikpukinskis »

rosser wrote: post #40
Robotbeat wrote: post #7

Tapping clathrates is a whole new vast source of carbon. If this becomes economical and drastic measures aren't taken to capture and store the emissions, the climate is basically toast. In the last few years, it has become quite obvious to me we're not going to ever run out of carbon before we, say, octuple (or more) the CO2 in the atmosphere. And the technology to get these fossil fuel sources improves just about as…

While completely true, this misses the crucial detail that burning the methane clathrates is pretty much the best case scenario for their release. They're coming out, one way or another. Right now, that means melting as methane, or burning to produce energy, yielding CO₂ — which, yes, would ideally be captured. Which would you prefer?

Maybe a better thing would be to use some of the energy to convert the rest to hydrogen for more stable storage?

Re: China claims breakthrough in mining 'flammable ice'

#46

Post by lightedman »

Retric wrote: post #3
lightedman wrote: post #2

Much better alternative to coal, at least. You emit far less CO2 per KWh generated and the only other byproduct besides CO2 tends to be water.

Probably though it depends on how much CO2 it takes to mine / transport / refine etc.

Move to methane-powered equipment to mine the methane. Or solar-powered.

Re: China claims breakthrough in mining 'flammable ice'

#47

Post by justicezyx »

aianus wrote: post #38
macmacaka wrote: post #24

Earlier quoted context omitted.

I don't get your point. Who are referring to are not being responsible here? The Chinese government or the Chinese people? If the former, they installed one-child policy with the sole purpose of population restriction, sounds pretty "responsible" to me. If the latter, are you suggesting as a people, maybe the Chinese shouldn't breed as many, to, say, leave space for other people?

If I choose to drive 1000km that I don't have to drive in a 35mpg Prius I am not more environmentally conscious than someone who drives 200km in a 10mpg Hummer. Similarly if I have 10 kids instead of 2. Anyways, I should have said "was irresponsible" since those decisions were made by their ancestors a while back and so there's not much more they can do about it now.

The analog is pretty unreasonable. It sounds like 1000km Prius driver has an option to drive only 200km. But they may not have. I.e. a poor lower middle class worker needs to drive everyday for work, while a millionare might choose to stay at home being environmental friendly. But he might be using too much electricity...

Plus, you cannot just bash Chinese government of killing baby, while at the same time calling them environmental irresponsible...

Re: China claims breakthrough in mining 'flammable ice'

#48

Post by rosser »

erikpukinskis wrote: post #45
rosser wrote: post #40

Earlier quoted context omitted.

While completely true, this misses the crucial detail that burning the methane clathrates is pretty much the best case scenario for their release. They're coming out, one way or another. Right now, that means melting as methane, or burning to produce energy, yielding CO₂ — which, yes, would ideally be captured. Which would you prefer?

Maybe a better thing would be to use some of the energy to convert the rest to hydrogen for more stable storage?

In the abstract, sure.

In the concrete, how viable is that technology? How efficient is it? How much of a hydrogen based energy storage infrastructure do we have to leverage for that?

Re: China claims breakthrough in mining 'flammable ice'

#49

Post by bildung »

philipkglass wrote: post #42
bildung wrote: post #28

Earlier quoted context omitted.

> I don't agree that you can just divide by population and say they're fine. CO2 output per country is not a reasonable metric. If we just split China into its provinces, does that make the problem go away? After all, each of the new countries now has a pretty small CO2 output.

The sustainability of CO2 emissions is measured in terms of emissions sources divided by its emissions sinks. A ratio above 1.0 means long term increases in atmospheric and oceanic CO2. The further above 1.0 we are, the less sustainable. To make a very crude approximation, terrestrial emissions sinks scale proportionally with area. (Slightly less crude: sinks scale with forested area.) Generally speaking, countries n…

You raise a good point, but I think we have to introduce exports and imports into the calculation. As most countries are not subsistance economies, but rather produce for consumption in other countries (and import other products themselves), those exports have to be attributed to the country whose population consumes them. The products that land e.g. in Wallmarts should be attributed to U.S. CO2 output, whereas meat produced in Argentina but consumed in China should be attributed to China.

Otherwise, the numbers don't make sense: China wouldn't release that much CO2 if nobody would import from China.

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