So what do we think of diesels now?

[soay]

Well, in retrospect, the diesel engine manufacturers over promised and under delivered, while the regulation agencies looked the other way. In fact, most of the governmental responses to the problems of human induced climate change - which as signatories to the Paris accord they have acknowledged is a real threat - have been ineffectual, as evidenced by the ever increasing percentage of CO2 in the atmosphere. The average is approaching 410 ppm, compared with about 310 ppm when measurements were started at the Mauna Loa Observatory in Hawaii in 1950. This is higher than at any time in the past 400,000 years, so it's unsurprising that we've just had the two warmest years on record, globally, and record low sea ice extent at both poles.

In aviation terms, higher temperatures are manifested as more water vapour and energy in the atmosphere, which rarely improves flying conditions.

[m.Berger]

And what instruments were they using to measure the PPM 400,000 years ago?
Sounds like poppycock to me that cannot be demonstrated nor proven, only asserted.

[abgd]

How about drilling a column of ice from antarctica then extracting air from bubbles and measuring it? There are more abstract ways such as looking at stomatae on fossil plants, which are unlikely to be as reliable but can be used to corroborate findings.

[Maoraigh1]

Does Mauna Loa produce CO2, which many volcanoes do? If so, why quote measurements from it?
Why would moving coal burning manufacturing processes to another part of the planet, (China) be expected to affect global warming?
I'm just mistrustful

[abgd]

Originally Posted by Maoraigh1

Does Mauna Loa produce CO2, which many volcanoes do? If so, why quote measurements from it?
...
I'm just mistrustful

It's a good question, for which you could find the answer with 2 minutes of googling if you were genuinely interested.

https://earthobservatory.nasa.gov/blogs/climateqa/mauna-loa-co2-record/

[horizon flyer]

Not a good idea to run a diesel car on Avtur it will wreck the fuel pumps as provides no lubrication for them. In all aero diesels, the fuel pumps have external lubrication from the engine oil by design.

What is needed is a low rev max 2700rpm, direct drive, with good power to weight ratio so the best way is a 2 stroke 3 cylinder or greater design. this means overlapping power strokes lower peak torque 1 power stroke/cyl/rev lower torque ripple and no torque reversal (prop driving the engine) plus lower revs needed for given power output.

All the 4 stroke designs have problems in several of these areas, so I don't think any of them are the long term solution.

One of the best would be the 8 cyl 2 row radial 2 stroke by Zoche been in development for over 20 years. Have seen the mock up at an airshow, very compact but I think it is now just an EU grants scam and will never see the light of day.

The hope is for the Delta Hawk V4 to replace the unreliable Lycoming IO360 as it works very well in the Cirrus SR20 they plan to have it certified in the next year.

There are other uniflow designs, single piston per cyl and 2 piston per cyl with both single and dual crankshaft models. The problem is engine development even with all this computer added design/manufacturing seems to cost a fortune and take for ever.

[soay]

Originally Posted by Maoraigh1

Why would moving coal burning manufacturing processes to another part of the planet, (China) be expected to affect global warming?

Where on Earth did you get that idea from? The only thing that effects is our ability to ask what's the point of reducing our CO2 emissions when they are relatively small compared to China? That's because we've offshored our manufacturing there, so the Chinese are emitting CO2 on our (UK, USA, Europe) behalf.

[LowNSlow]

abgd: all the ice core samples demonstrated that temperature increase preceded CO2 increase..... Ooooh hockey stick.
Follow the money......

Back on track:

Diesel engines: trains, trucks and tractors.

The cr@p that ships burn isn't even close

Jet A1 in cars, bad move, jet fuel doesn't have to lubricate fuel pumps which is why it's lubriscity is much lower. Cue problems making ex-car diesel engines run on Jet-A1.

[abgd]

all the ice core samples demonstrated that temperature increase preceded CO2 increase..... Ooooh hockey stick.

No, not all of them - specifically the most recent one. As I understand it the argument goes that increased temperatures increase CO2 and Methane emissions which in turn increase temperatures, so there's a positive feedback loop which amplifies temperature fluctuations due to natural minor 'insults' such as changes in the Earth's orbit that would otherwise cause only small changes in temperature:

https://www.newscientist.com/article...lobal-warming/

I'd agree it's not quite such a straightforward story as 'CO2 rises, then temperature rises after'. But straightforward stories only take you to O-levels/GCSE level.

The problem with climate science is that it's thoroughly messy. For example, the following article supports the idea that CO2 and Methane cause climate change:

http://www.nature.com/articles/srep21691

I think I could understand this at a low level if I had a few months to devote to it and access to scientific journals again. If you gave me a few years I could get to a point where I could hold and defend an opinion on whether it's good science or bunkum or something in between. I'd have some idea about where the weaknesses in the arguments lie and which questions are more-or-less settled.

I have a background in biomedical science which is similarly messy. I have a shallow understanding of some of the mathematical techniques used. But the truth of the matter is, I'm not a specialist in the field and something tells me that you're not either.

Will power grids be able to cope with intermittent renewable supplies? Are most refugees genuine, and do they pose any risk to us? Is the NHS collapsing because of underfunding, lazy doctors, the ageing population or deliberate mismanagement with a view to privatisation? How bad are diesel fumes for our health? Will Brexit be good or bad for the economy? Should we all be taking statins?

None of us are likely to be experts on more than one of these issues, if any. And yet if we wish to be citizens partaking in public discourse we need to hold opinions about the issues that seem important to us, and what to do about them. So how do we decide whom to trust as advisers?

[soay]

Originally Posted by LowNSlow

all the ice core samples demonstrated that temperature increase preceded CO2 increase

That's like saying that people died of cancer before tobacco was smoked, so smoking can't cause cancer. It's a logical fallacy.

Natural processes buried megatons of carbon, in the form of coal, oil and methane, which we are burning and releasing their products of combustion into the atmosphere. This is why the current CO2 increase is triggering the temperature increase, rather than following the natural pattern. Of course, once temperatures get high enough, positive feedbacks will kick in, naturally releasing greenhouse gases stored in currently frozen methane clathrates. That's when we will lose all ability to prevent runaway temperature increases. Observations indicate that this process may have already begun.

[andytug]

Originally Posted by abgd

Will power grids be able to cope with intermittent renewable supplies? Are most refugees genuine, and do they pose any risk to us? Is the NHS collapsing because of underfunding, lazy doctors, the ageing population or deliberate mismanagement with a view to privatisation? How bad are diesel fumes for our health? Will Brexit be good or bad for the economy? Should we all be taking statins?

None of us are likely to be experts on more than one of these issues, if any. And yet if we wish to be citizens partaking in public discourse we need to hold opinions about the issues that seem important to us, and what to do about them. So how do we decide whom to trust as advisers?

You would need to find those without a vested interest, nor funded by any private company or government department with an agenda.
Problem is I suspect those kind of scientists no longer exist.

[soay]

Originally Posted by andytug

You would need to find those without a vested interest, nor funded by any private company or government department with an agenda.
Problem is I suspect those kind of scientists no longer exist.

With all the fake news about these days, it's easy to become distrustful of everyone, but bear in mind the relative scale of the agendas. The only possible one that scientists from all over the world researching climate change could have in common would be keeping on some notional gravy train. Compare that with the implications for the fossil fuel corporations if we all have to stop burning their fuels. It's an existential crisis to them, so they have responded with a propaganda campaign to sow seeds of doubt on the science and the scientists who are threatening their livelihood, using the tactics so successfully employed by the tobacco corporations. ExxonMobil, for example, employ scientists who warned them in the 1970s that burning fossil fuels would cause global warming. Since then, they have spent more than $30 million on think tanks that promote climate change denial. Ask yourself which agenda is most likely.

[abgd]

You would need to find those without a vested interest, nor funded by any private company or government department with an agenda.
Problem is I suspect those kind of scientists no longer exist.

So do you give up on all scientific knowledge?

It seems to me that most corporate and government interests are not sympathetic to the idea of man-made climate change and the need to do something about it. At least, this has not historically been the case. Sure, there will always be people (e.g. wind-turbine manufacturers and solar panel manufacturers) who will benefit from action on climate change, but as Soay points out, my feeling is that their political and economic power has historically been far less than that of the oil companies. US and Canadian administrations in particular have been actively hostile to climatologists, even removing publicly funded data from the public domain on occasion: book burning for the 21st century.

https://www.wired.com/2017/01/rogue-...te-data-trump/

It seems to me that scientists who state that they believe in global warming are acting strongly against their own interests, so if anything I feel this strengthens their claims.

That leaves accusations of groupthink. Having been a scientist, my own bias and sympathies are towards scientists. A good scientist really is a truth-seeker. Sure, you want to win the respect of your peers with decisive and well executed experiments - but you are also well aware that you could lose your reputation if your claims turn out to be untrue. In my own field of psychology there have been bad eggs who've falsified results. But that field tends to be the preserve of small groups working on research that is never replicated. Climate change science is more likely to involve big groups of people - think how many people are involved in launching a satellite or drilling an ice core and how hard it would be to conspire to manipulate a result. The science is replicated and contested. Errors are uncovered and corrected. To me, it seems likely to be good science, with the caveat that the error bars are always going to be big because it's inherently a messy field to work in.

[Basil]

The much touted 40,000 deaths pa is 'notional deaths'. People aren't ACTUALLY dying.
They work out that people MAY die a month earlier, multiply that by the number of actual deaths and come up with this imaginary figure.
e.g.: England & Wales 530k deaths pa x 1/12 = 44k

People are ACTUALLY living longer now.

This Diesel thing is just another Project Fear.

[mm_flynn]

Originally Posted by Basil

The much touted 40,000 deaths pa is 'notional deaths'. People aren't ACTUALLY dying.
They work out that people MAY die a month earlier, multiply that by the number of actual deaths and come up with this imaginary figure.
e.g.: England & Wales 530k deaths pa x 1/12 = 44k

People are ACTUALLY living longer now.

That actually isn't how they do it. They look for correlations in death rates vs exposure to various factors (such as high levels of particulates). This is how 'deaths from' indirect or cumulative causes are worked out. This would include factors such as particulate pollution like diesel, water pollution, cigarette smoking, radiation exposure, lifestyle choices, genetic variances, etc.

The fact that people are living longer only says the benefit of various favorable factor changes and generally increasing health spending is more than offsetting negative factor changes.

Diesel particulate is as much project fear as was addressing sewage in drinking water and the coal driven London Smogs of the past.

[Silvaire1]

What do I think of diesels? The same as I've always thought of diesels: the unrefined fuel stinks and doesn't evaporate, the particulate smoke stinks and blows directly in your face when you're walking or riding a motorcycle (even with the newest technologies), they make urban buildings black, they are over complex and expensive to maintain (particularly for aircraft) and their existence on the road is the result of a European regulatory and tax regime that disingenuously forces people to drive them for the sake of energy security that would be better achieved by other means. And they are built by liars. I've driven them both old and new, disliked them from inside and particularly outside, and will never own one. Exactly the same opinion I had of them 10 years ago.

In my experience the very worst thing about European roads is Diesel engines: they are western Europe's 21st century version of the 20th century East Block two stroke. It's an honest relief when I can escape Diesel engines to roads where they aren't so prevalent. I hope that with the aimless political wind now by luck blowing against them they'll be gone in due course, sooner rather than later.

[Parson]

Well I was going to buy a Golf GTD but I'm now looking at a GTI.

Did fly a converted C172 diesel a few years back. Was so nose heavy, wasn't able to trim enough nose up on approach - dangerous.

[ZFT]

Just bought 3.6 turbo deisel. Why? Deisel is 25% cheaper than petrol where I reside. Simple economics and I have no faith or trust in any of these reports anyway.

[Elephant and Castle]

I despair when I see a group of people who on the face of it should be intelligent spout such strong opinions on things they know next to nothing. How are we ever going to make any progress or fix our problems if any solutions are immediately dismissed as lies by people who not only know very little but also lack the intellectual curiosity to follow the scientific method to back their claims.

[S-Works]

I love my diesels. My car is a new Cayenne S Diesel and is smooth powerful and a delight to drive with massive torque all delivered low down. My Motorhome is Diesel, my wife's car is diesel, my Landrover is Diesel.

They will pry my Diesel engines from my cold dead fingers........