h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Listening to the last of this years lectures this week I was struck by some 'facts' regarding our use of fossil fuels, carbon emissions and ozone damage.

Apparently it takes one tonne of aviation fuel to fly each passenger from Heathrow to Australia, and all the carbon misions from that are occuring at high altitude , where they cause the most havoc. Moreover aviation fuel is the only one which is not taxed - senseless or what?

In the same vein it takes about one hour to fly from Edinburgh to London where one gets frequently 'stacked' for up to 40 minutes before landing, thus wasting more untaxed fuel. Similarly aircraft often sit in taxi-ways with engines running to wait for a take-off slot.

Where is all this leading?

If one travelled by train from Edinburgh the use of electric traction doesn't cause carbon emissions, except at the point of generation. So should we as a country not be looking VERY seriously at our methods of generating electrical power, and in the current volatile world should we not follow the French example?

France generates all of it's electricity without using non renewable or carbon emitting energy by producing 70% from Nuclear and the rest from Hydro systems.

IMHO we should build more nuclear stations and gradually rid ourselves of the dependancy on imported oil /gas and at the same time move towards renewable energy sources.

Opinions canvassed

Novo

Mornin Novo,

Just been doing a bit of research before I throw in my worth. I've argued before that nuclear is the only practical method available to us, at the moment, from a sustainable viewpoint. I think tidal power will eventually contribute but development times are long.

What I am surprised at are the comaparative costs taking into account factors such as commissioning, generating, de-commissioning, standbye generation cost and carbon charge. Costs per kWh are:

Nuclear 2.3p
Gas 3.4p
Coal 5.1p
Onshore Wind 5.4p
Offshore Wind 7.2p

The figures are from the Uranium lobby but they are drawn from sound sources such as OECD reports. My money is on nuclear and now the election is out of the way I would expect to see a green paper. I don't see any other way of reducing our carbon emmissions.

If you look at the human population of this planet, and conclude that the root of the problem is that we are vermin - a plague (there are ten times more humans than sustainability and comfort would dictate) - another way starts to reveal itself....

Pattern-chaser

"Who cares, wins"

Yes, but, technological and scientific advances, at least for the wealthy, keep up with resource demand. Cetainly in Europe we don't suffer from population explosion, just the reverse, birth rates are falling and who's going to pay my pension?

>>Apparently it takes one tonne of aviation fuel to fly each passenger from Heathrow to Australia

Do you have any support for this statement? Just out of curiosity, because it seems like a very high number. And I've heard that over long distances flying is the cleanest way to travel (or maybe that was the cheapest, not sure anymore).

anyway, all for nuclear power. Clean and cheap. Only the waste is a problem.

Rod

From an environmental point of view I think the risk from storing spent nuclear fuel is less than continuing to pump CO2 into the atmosphere.

Hi Rod,

No, is the short answer ,I was just quoting from the lecture. Presumably the Beeb could supply the text and the question may be answered in references.

Sorry
Novo

I heard that a 737 burns 2 tonnes of fuel per hour and a 747 uses roughly the same as a mini per person. So, assuming about 50mpg for the mini you could go 13,000 miles on a tonne. Sounds about right.

Our recently elected government is I think comitted to a 60% CO2 reduction by 2050 (correct me if I'm wrong), and this will probably be achieved by a new nuclear programme. Nuclear is not the best option, it is the only option in the short term.

Hi DB,

I agree Tidal power is a better option long term but there's not a lot of support out there, yet, but we're on the case. What do you think is a better medium term option.

Hi Mr Ross,

medium term ... nuclear again I guess. I don't believe renewables could ever replace coal/gas/nuclear but every little bit helps and each new windmill / solar panel / tidal float thingy is a step in the right direction. Perhaps fusion will be feasible when this new generation of fission reactors get too old. Are you actually involved in tidal then?

Yes, I'm helping a mate, who has a patented design, to develop the technical and the commercial aspects. It is always tough for inventors bringing their baby to the big bad world. But we're trying.

'another way starts to reveal itself....'




Soylent Green is people!!!!

Here we go again. I feel like I only remain subscribed to this thread to correct people who didn't pay attention in Chemistry lessons.

"Apparently it takes one tonne of aviation fuel to fly each passenger from Heathrow to Australia, and all the carbon misions from that are occuring at high altitude , where they cause the most havoc. Moreover aviation fuel is the only one which is not taxed - senseless or what?"

Fact 1: Burning high-purity kerosene (jet fuel) releases very little carbon dioxide emission, compared to nasty unsaturated petrol. The contribution of jets is negligible compared to other carbon-burning resources. Their main waste product is water vapour, which is a much more powerful greenhouse gas in any case.

Fact 2: It makes no difference at what altitude carbon dioxide is released, the overall greenhouse effect is the same. In fact, it is probably marginally better to release it higher in the atmosphere, as less radiation will reach it.

B

Are you thinking of a different thread B? This one has only been around for a few hours so not quite sure it deserves the level of exasperation expressed.

*deep breath*

Nearly the weekend though hey?

Err, polite cough,

Fact 1: Their main waste product is water vapour, which is a much more powerful greenhouse gas in any case.

Well wouldn't it be better to reduce the production of water vapour by taxing the oh so pure JetA

Fact 2: In fact, it is probably marginally better to release it higher in the atmosphere, as less radiation will reach it.

Presumably pumping water vapour out at high altitude is a good thing because it reflects solar radiation and reduces the greenhouse effect?

Mmm. A quick google reveals:

2% CO2 emissions currently attributed to air travel, but expected to rise drastically. The altitude problem is not the CO2, but the contrails and ozone formed from NOx emissions from the engines, which is also a greenhouse gas.

<>

Again via google - kerosene emits 2.7kg per litre when burnt; diesel 2.68kg (as you would expect since they are basically the same thing); petrol 2.31kg and LPG 1.51kg.

On a personal note, I find it rather ludicrous that it's now cheaper to fly to most major European cities than it is to catch a bus. Never mind a train. Much of this is undoubtedly due to lack of tax on aviation fuel. Just how are the railways supposed to compete with that?

"Presumably pumping water vapour out at high altitude is a good thing because it reflects solar radiation and reduces the greenhouse effect?"

No, not really. The greenhouse effect is caused by infra-red radiation reflected outwards by the Earth. If water was in the way, all it would do is make us colder.

Jet engines in flight do not produce a great deal of nitrous oxides. NOx gases are formed when engines are left running on the ground and overheat. What you are also missing, Dave, is that a jet engine scrubs a lot of its carbon waste products for use in the afterburner.

B

Presumably the infra red radiation is generated by incoming solar radiation hence if you reduce the incoming solar energy you reduce the outgoing infra red energy and reduce the greenhouse effect.

That would be the case. But water doesn't reflect any large quantity of infra-red. It absorbs it, which is what creates the greenhouse effect in the first place.

B

Airlines not only got a multi-billion $ tax break in not paying tax on fuel, but they don't pay value-added tax either. We're actively subsidising them, and I'm personally not very happy about it.

I read somewhere that a train from Edinburgh to London releases 10% of the CO2 emissions that a plane does. Never mind the chemistry, it's a law of physics that it takes more energy to get a 100-tonne aircraft 7 miles high than it does to get a train rolling along some tracks.

PS, British Airways' largest route in terms of passengers from London? New York? Paris? Naaawww, it's Edinburgh!