|Paul Lousick||24/02/2020 00:44:16|
|1541 forum posts|
The majority of coal mined is thermal coal (steam coal) and is used in power plants for producing electricity and there are many alternative souces for producing it. Wind power, ocean wave power and that big thermo nuclear reactor in the sky that powers solar panels.
Another type of coal is metallurgical coal (coking coal) which is used in a blast furnace for producing steel. Electric furnaces are used to re-melt steel but not make it and they require an enormous amount of electricity. At the moment, there is not a substitute for it and if we stopped mining coking coal, steel production would grind to a halt.
Electric arc furnaces are used for making aluminium and a smelter near Newcastle, Australia produces 580,000 tonnes of aluminium per year but uses 10% of the total electricity for the state of NSW.
4804 forum posts
The 96 (actually it's 97, I stand corrected) per cent consensus among the relevant published scientific work has been the subject of numerous meta-studies and has been confirmed beyond doubt. You ask if there is anyone who knows the answer? These guys do.
Like I said in my intiial post I'm not going to argue the points of science. I leave that to the scientific experts, the 97 per cent of highly qualified scientists who actually know about this stuff at expert level and say manmade climate change is a serious problem. If you want confirmation of the 97 per cent consensus that you are wrong, look at this study: Consensus Confirmed
"The consensus that humans are causing recent global warming is shared by 90%–100% of publishing climate scientists according to six independent studies by co-authors of this paper. Those results are consistent with the 97% consensus reported by Cook et al (Environ. Res. Lett. 8 024024) based on 11 944 abstracts of research papers, of which 4014 took a position on the cause of recent global warming. A survey of authors of those papers (N = 2412 papers) also supported a 97% consensus. Tol (2016 Environ. Res. Lett. 11 048001) comes to a different conclusion using results from surveys of non-experts such as economic geologists and a self-selected group of those who reject the consensus. We demonstrate that this outcome is not unexpected because the level of consensus correlates with expertise in climate science. At one point, Tol also reduces the apparent consensus by assuming that abstracts that do not explicitly state the cause of global warming ('no position' represent non-endorsement, an approach that if applied elsewhere would reject consensus on well-established theories such as plate tectonics. We examine the available studies and conclude that the finding of 97% consensus in published climate research is robust and consistent with other surveys of climate scientists and peer-reviewed studies. "
Edited By Hopper on 24/02/2020 03:47:31
Edited By Hopper on 24/02/2020 03:51:15
Edited By Hopper on 24/02/2020 03:51:47
|878 forum posts|
".......somewhere between 90% and 100% that agree humans are responsible for climate change........."
Come on, really? Please explain therefore why climate changed when there wasn't humans around, millions of years ago, or more comparatively recently, over the last few thousand years when there were world populations back then of maybe only a few millions.
Climate has always changed, the only augment today surely is how much are humans currently aggravating it.
6315 forum posts
The problem is the speed with which climate is changing. Previous climate change was a slow process taking at least tens of thousands of years to shift and more usually tens of millions or longer. The first clues something strange was happening to our climate appeared only 50 years ago, and - whatever is causing it - the change is accelerating.
Unfortunately cause and effect aren't bleeding obvious yet, and it will be too late when it is. The evidence isn't as clear-cut as that proving the earth orbits the sun rather than the other way round. (Can anyone prove that without looking it up!)
Instead evidence pointing to global warming consists of a mass of data from many different research fields collected over different time periods. Highly indigestible to the man in the street, just as are the data-sets used for next week's weather forecast and managing the futures market. While it's possible to dismiss data-sets one at a time, it's much harder to explain away a common trend in the same direction coming from different sources.
Equally important, there isn't an obvious alternative that explains the data. If the cause of global warming isn't human activity, then what is? That question is hard to answer. One reeponse is outright denial that there is any such thing as climate change; this one held water 20 years ago, now it's looking foolish. Otherwise, it's necessary to come up with an effect capable of causing the whole planet to warm as quickly as it is. What, how?
Past climate change has been explained reasonably well, such as prolific plant growth taking hundreds of millions of years to convert Carbon Dioxide to the Oxygen we breath today. But as far as I know, no-one in the Deny Camp has a hypothesis explaining what's happening at the moment. Instead it's easier to cherry pick point weaknesses in the complex evidence in favour, and it's usually done by people like us with a relatively poor grasp of science, statistical methods, and scientific method. Bloke down the Pub talking 'common-sense', or god forbid a politician, is much more user-friendly, even though they're guessing. Chaps who fill out a cryptic crossword without reading the clues get quick convincing results, wonderful apart from being completely wrong!
Experts aren't infallible, but it's far more likely they will get the right answer than averagely intelligent chaps dipping haphazardly into unfamiliar subjects. Good example on the forum at the moment. The discussion about tensioning boring bars has reached the stage where a Finite Element Method analysis would be helpful. Although FEM is a well established technique, we're stuck because we don't appear to have a member able to use it. Despite that I think we all know it would be stupid to reject FEM as a meaningful tool just because wonderfully talented Model Engineers don't understand how to drive it. Yet faulty logic is applied to climate change: it's being rejected because people don't like the idea and can't be convinced because they don't understand the analysis. They might believe it when there is no transport, no electricity, no water, and no food...
|Jeff Dayman||24/02/2020 11:47:51|
|1888 forum posts|
Now that is an effect I have personally observed several times!
|Neil Wyatt||24/02/2020 11:53:19|
18231 forum posts
I think we all know the figure refers to the ongoing, rapid change.
|Neil Wyatt||24/02/2020 11:55:59|
18231 forum posts
|Martin Kyte||24/02/2020 12:30:57|
2055 forum posts
The phasing out of soft house coal is interesting as an example of conflicting aims. Coal is a hydrocarbon and the various grades of coal are largely defined by the carbon/hydrogen ratio. When burnt part of the heat out put comes from Carbon and part from Hydrogen and other volatiles. Heating coal in the absence of oxygen produces coke and town gas (hydrogen(50%),methane(35%),carbon monoxide(10) and ethylene(5%)) of which the hydrogen at around 50% merely produces heat and water so is quite environmentally freindly.
It is clear to see that the more volatiles in the coal the less CO2 will be produced for the same heat output as more heat will come from hydrogen, methane and ethylene and less from pure carbon. So as far as CO2 is concerned banning soft coals and burning anthocite coals will increase the CO2 output assuming the number of coal fires stays the same.
Soft coal however produces more pollutants in the average domestic hearth. Open fires are not brilliant at complete combustion and a lot of the soot and ash particulates are sent up the chimney with no filtering or any other clean up so in order to improve air quality smokeless coal is better.
So you pay's your money and takes your pick, either less CO2 and more air pollution or more CO2 and cleaner air.
Personally I think that the CO2 output trumps everthing at this point in time.
As an additional comment, we may be better to return to town gas with it's nice clean 50% hydrogen rather than the high methane Natural gas we use today.
|878 forum posts|
Neil, you may well be right, but that is not what was written, and without constantly following all the comments and claims made everywhere, in the press and on the internet, one does not necessarily know what was meant, as opposed to what was written. Never assume.
|980 forum posts|
Forgive me but have I missed something here? I thought that the phasing out of coal and wet wood is an attempt to reduce the emissions of toxic and carcinogenic particles.
I am sure the Telegraph and Times had similar news items.
Edited By JA on 24/02/2020 13:06:13
Edited By JA on 24/02/2020 13:07:35
Edited By JA on 24/02/2020 13:08:04
Edited By JA on 24/02/2020 13:08:52
|Martin Kyte||24/02/2020 13:09:20|
2055 forum posts
It is. I just thought it was interesting how one goal can pull in the opposite direction to another.
Edited By Martin Kyte on 24/02/2020 13:33:17
|Phil Whitley||24/02/2020 13:34:57|
1256 forum posts
Chaps, 0.8 to 1.2 deg change in temperature since 1900 is hardly rapId, please give some evidence of RAPID change from an independant source, not the IPCC. There is plenty of data out there that completly debunks the "concensus" In order to get a consensus among scientists you need ask only two questions.
Has the climate warmed since 1900?
YES it has
Does human activity have an effect on climate?
YES, it does.
not really hard to do but it means absolutely nothing, and the purpose of it is to STOP PEOPLE ASKIHG QUESTIONS!
|Paul Kemp||24/02/2020 21:34:26|
|559 forum posts|
Thanks for that, that gives me a reference against those credited in the IPCC report and some further info to look at. As regards your statement "that you are wrong" what pray am I wrong about? I have not made any reference to an opinion either for or against and in my first post clearly stated up til recently I have no opinion, that has not changed. I will form an opinion eventually based on looking at all the arguments on both sides. There I think lies the problem firstly with your 'assumption' that by asking questions I have committed to denying climate change! Secondly with your statement "I'm not going to argue the points of Science. I leave that to the Scientific experts" so it seems to me you are quite happy to accept a study proclaiming 97% of those experts are right (and I am sure the study is perfectly valid) without even examining any of the evidence they offer to support their conclusions!
Neil's link later to critical thinking is more the process I wish to adopt. There is no need to argue with the experts but a critical review and broad understanding of the reasons for their conclusions doesn't as the article states require a PHD in climate science. I am afraid I was born awkward and not prepared to accept the opinion of 97% of my neighbour's that if I go past the top of the hill out of our town I will fall off the edge of the world! The first two para's on Niel's link and particularly the second really highlight the situation for me.
There is a lot to be gained and lost on following the current course, I am not yet ready to jump on any bandwagon.
So I will repeat my last question to you in a different way, is there anything else that really convinced you in your opinion (evidence based and referenced and not presented in the media) apart from the consensus of the 97%?
4804 forum posts
I dont have an opinion on it. Its not a matter of opinion. Its science. I dont claim to have gleaned enough scientific knowledge from google to know more about it than 97 percet of the 10,000-plus scientists who specialise in the field. That would be plain stupid of me, a perfect example of the Dunning Kruger effect at work.
I might as well go and tell the nuclear physicists how to run a power station or particle collider or tell the cardiac surgeons how to do a triple bypass or tell Einstein his theory of relativity etc is wrong because you cant bend light or see gravity.
Edited By Hopper on 24/02/2020 23:06:18
Edited By Hopper on 24/02/2020 23:33:17
4804 forum posts
Double post. Oops.
Edited By Hopper on 24/02/2020 23:07:05
|Martin Kyte||25/02/2020 08:58:51|
2055 forum posts
Well whatever anyone 'chooses' to believe they had better hope that climate change is man made, because if it's not we have no way of doing anything about it and it's goodnight nurse.
|Derek Lane||25/02/2020 09:36:14|
344 forum posts
Someone with more knowledge than myself may know the answer to this question.
If the weather is down to us humans how long does it take for the "pollution" to take effect in changing the weather, if this weather that we are having now was caused by all the smoke and smog of the victorian era then with all that has been done so far must contribute to reducing the weather?
|Russell Eberhardt||25/02/2020 10:05:40|
2600 forum posts
Rather than arguing with the small number of people who don't believe the science, perhaps we should consider what can be done to reverse the rise of CO2 in the atmosphere. This is closely tied to our energy use. Fossil fuels are being used faster than they are created and so will run out. How can we make our energy use sustainable?
A few years ago the Conservative government pointed out that mobile phone chargers use about 1 W when plugged in but not charging and said that if we all unplugged them when not in use we would save enough energy to power 66,000 homes for a year. However 66,000 out of 25 million homes in the UK is an insignificant saving, less than 1/4%. We don't need small savings but big ones.
Any practical ideas?
|Mike Poole||25/02/2020 10:39:56|
2735 forum posts
A big win is probably going to be difficult. Many of our new buildings are not being built to the best possible standards, every new home should have charging points or at least the infrastructure to easily install one, solar panels and a south facing roof should be standard and so on. We are just watching things fall apart around us, action is required but least think it through properly unlike the diesel fiasco.
4804 forum posts
Here in sunny Australia, solar -- both domestic rooftop and massive commercial "panel farms" -- have been so popular and effective they are disrupting the traditional power industry bigtime and the grid infrastructure is struggling to keep up. But that will be fixed in time. And now for power at night, they are using solar to pump water uphill to reservoirs in the day and running it downhill through turbines at night. Early days yet but solar and wind power are already major players here.
MIght not translate that well to somewhat more drizzly and cloudy UK though?
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.