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Climate change

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Airborne_Again wrote:

Has also the rate of change in previous periods been as large?

Most certainly much faster depending on what it is you actually mean. Remember that the earth’s atmosphere has only 1/1000 times the heat capacity of the earth’s oceans. Heating up the entire atmosphere 10 degrees, is equal to heating the oceans 0.01 degree (on average). It’s the oceans that decides how the climate changes, not the atmosphere.

How much energy is needed to melt the ice on Greenland, an ice sheet much smaller than the ice sheet of the last glacier period ? Well, rough estimates are an energy equal to 30-40 times all the coal reserves in the world, or 20 times all the oil and gas reserves in the world. The energy needed is unimaginable. 65 million years ago a huge meteor impacted Mexico. It wiped out the dinosaurs and almost every other large life form. The rate of change was catastrophic, from heaven to hell in a matter of hours, instantly close to the impact. Even so, that impact energy is not enough to melt the ice on Greenland. Two such impacts are needed.

Still we hear that “global warming” will melt the ice sheet of Greenland within 100 years, and increase the sea level by 7 meters. How exactly is that supposed to happen? by heating the atmosphere 2 degrees? It will take millions of years using that method. The last ice age covering most of Europe and North America (much larger than Greenland) melted in roughly 20k years. Why those those ice ages come and went is a big mystery, but it reasonable to believe there is a connection with unstable semi-cyclic global ocean currents with periods of thousands of years, simply because only the oceans have enough energy stored to make a difference.

How are we to react to this? If we consider that greenhouse gases will increase the temperature some 2 degrees. It will still most likely take thousands of years before that effect is seen on the climate (the oceans). Thousands of years is a ridiculously long time to plan ahead, and in any event, it is way to late to do something about it now.

LeSving wrote:

How much energy is needed to melt the ice on Greenland, an ice sheet much smaller than the ice sheet of the last glacier period ? Well, rough estimates are an energy equal to 30-40 times all the coal reserves in the world, or 20 times all the oil and gas reserves in the world. The energy needed is unimaginable.

I don’t see how this comparison has any relevance whatsoever. It’s not the heat generated by burning coal, oil or gas that causes the global warming.

How are we to react to this? If we consider that greenhouse gases will increase the temperature some 2 degrees. It will still most likely take thousands of years before that effect is seen on the climate (the oceans). Thousands of years is a ridiculously long time to plan ahead, and in any event, it is way to late to do something about it now.

So you’re saying that essentially all the climatologists in the world don’t know what they’re doing, but you do? In that case further discussion is pointless.

ESKC (Uppsala/Sundbro), Sweden

A large meteor strike will put dust and ash into the air and cause a period of global cooling, but my understanding was that the arctic circle wasn’t covered in ice 65 million years ago anyway, so it’s not surprising that it didn’t melt.

Solar irradiance provides much more power than do all our other methods of energy production. If solar panels were 100% efficient and you had some form of energy storage and distribution network you could meet all the world’s energy needs several times over by covering an area the size of Wales. Trapping a small proportion of this energy (which is how the greenhouse effect works) would heat the world more than burning all the fossil fuel reserves, so that argument is irrelevant too.

Last Edited by kwlf at 15 Apr 22:10
EGCW

kwlf wrote:

Trapping a small proportion of this energy (which is how the greenhouse effect works) would heat the world more than burning all the fossil fuel reserves, so that argument is irrelevant too.

I don’t think it is the heat from fossil combustion that heat the world, or any sort of earth heat source for that matter, including from earth core, as you said it is mainly solar energy, the question how much proportion of it is radiated outside in infrared bands?

The proportion of earth radiation seems to depends a lot on how much CH4/CO2 you have in the air and the thickness of the atmosphere, the latter is not changing in the next 10million years, while the spike of the former does relate to human activity from “liquid avgas” buried deep in land and/or from natural activity of “calcium carbonate deposits” buried deep in water

kwlf wrote:

A large meteor strike will put dust and ash into the air and cause a period of global cooling, but my understanding was that the arctic circle wasn’t covered in ice 65 million years ago anyway, so it’s not surprising that it didn’t melt.

I would not go that far in the cycle, climate change/global warming has to do with change in temperature from -10m years to now at atmospheric pressure = 1bar

On atm pressure at -65m, from size/aerodynamic of birds that flew between -100m and -65m (e.g. flying dinosaurs before meteor strike) one can estimate that you need 5bar atm pressure to get sufficient “density altitude” for these things to fly (or swim if you like ), while we don’t know what was atm pressure from -4bn years to -200m years, it is difficult to think of ice melting/water evaporating in terms of temperature scale

Last Edited by Ibra at 15 Apr 23:26
ESSEX, United Kingdom

It’s always cheap to say that because someone questions the current politically correct science that “further discussion is useless”.

Any theories, accepted or not, need banging on the foundations from time to time to see if they hold up. In recent months I have been attending a number of climate seminars which both pro and contradict the current mainstream science but all of them pose valid questions. From the reaction of those scientists who still keep an open mind, it also has become clear to me that things are way more complex than they are presented to the public these days, mainly because they are beyond comprehension of the general public, so they have to be “explained” or “interpreted” to make sense.

I think what LeSving calculates up here is probably flawed but the question is still valid: It does take energy to melt polar ice and it also takes tremendous energy to change the ocean temperatures. How can a 2 degree air temperature change have this profound effect which is claimed? Which does not mean it can’t and “all the scientists are wrong” but if so, then there must be an answer to that and not simply a refuse of discussion. If the simple physics involved there are so outrageously wrong, then the answer should be easy.

Where I think the thought process there may be wrong is that it disregards the radiation calculation which is what causes the green house effect to actually happen. Nevertheless, the energy needed to cause these global phenomena does not change from that, it is simply the source of the engery which changes. Also it should be clear that it does not take the melting of ALL the ice to cause quite undesirable effects but only of a sizable fraction.

Yet it is certainly not wrong to question some of the more sensational predictions, as what nature does in the end is always somewhere in between the worst and best cases.

As for the science community being wrong in some things they proclaimed set in stone, it is rare but not unherad of…. However if I have learnt one thing in my dealing with science and particularly meteorology and climatology it is that in those particular fields it is even more important to keep questioning everything very often as a lot of stuff changes without giving prior notice to the said community and continuously so. I saw a really interesting presentation the other day about temperature development in some urban areas which defy mostly what modelling does up to now due to the fact how the underlaying sensoric works. Whether it’s relevant is totally up in the clouds but it got some people thinking.

LSZH, Switzerland

Mooney_Driver wrote:

It’s always cheap to say that because someone questions the current politically correct science that “further discussion is useless”.

It’s not cheap when someone rejects the scientific consensus without any own expertise in the area and without any argument.

How can a 2 degree air temperature change have this profound effect which is claimed? Which does not mean it can’t and “all the scientists are wrong” but if so, then there must be an answer to that and not simply a refuse of discussion.

The 2 degree temperature increase is a global average. Not a uniform increase. You don’t have to read scientific papers to know that. By now that should be well known by everyone who is actually reading newspapers or watching more than soaps on TV.

ESKC (Uppsala/Sundbro), Sweden

Lovely example of the absurdity of some of the actions of protesters: a famous British actress felt enough about the protest in London she actually flew back from the US to attend. Well, now Emma Thompson has to realize that the crowd there does not think that was a great idea. Simple example which shows how easily you can get from activist to pariah in one day. Maybe some other verbal stone throwers should think about that too… how climate friendly was it that many people travelled to London to attend that rallye with whatever means? Certainly some which came from central Europe must have flown in…

Maybe a bit more reasonable behaviour would help the issue more than constant stone throwing and fingerpointing…

Airborne_Again wrote:

By now that should be well known by everyone who is actually reading newspapers or watching more than soaps on TV.

Certainly.

But if you feel so strongly about it, how come you still fly?

It’s funny to see that threads like this run in almost all aviation forums and there are people who vigorously defend the protest crowd who gladly would have us all grounded, have affordable air travel prohibited and half of us eliminated to save the planet…. Somehow appears a tad confusing.

Last Edited by Mooney_Driver at 20 Apr 05:14
LSZH, Switzerland

As I mentioned, I fully accept that climate change is happening but I despair at the Government responses which are both expensive and also don’t address the problem at all. I also despair at the “crying teens” in London. The worst thing is these “teens” only believe the propaganda fed to them by their teachers.

When we were at school we had different propaganda (at that time our teachers were telling us that “mans sins” were to be punished by (a) the forth coming ice age and (b) Nuclear Armageddon). The difference then is whilst we had a deep respect for some teachers, most pupils had a healthy disrespect for those teachers who were patently trying to force their dodgy views down out throats. In the almost pre-internet/ pre-smartphone era teens seemed to be able to think for themselves much more than the present “Facebook” generations.

Look at this graph below

So perhaps a better policy would be to fund research into things like PV and get the efficiency up from the best current levels of 22% to much higher levels. There are already ideas out there and when PV becomes cheaper than normal energy without subsidy then it will be more widely adopted.

I believe PV is already a great idea in the Med and Africa. BTW as pointed out to me above, I was wrong with my flippant comment about the embedded carbon on manufacture but it doesn’t change my mind about PV working properly in the UK. The sun doesn’t shine enough in winter.

I have always found Bjorn Lomborg an interesting perspective to counter the Hysterical BBC and Guardian “reporting”. You will see the BBC now has a Trustpilot rating of 1 out of 5 on 3,400 reviews which I find interesting.

https://www.lomborg.com/press-release-research-reveals-negligible-impact-of-paris-climate-promises

United Kingdom

Airborne_Again wrote:

I don’t see how this comparison has any relevance whatsoever. It’s not the heat generated by burning coal, oil or gas that causes the global warming.

That wasn’t the point (wasn’t that obvious? I wonder why not) Anyway, the point is, you need an excess energy source of this magnitude to melt the Greenland ice. The energy needed is unimaginable. This is basic thermodynamics of water and air. By heating the atmosphere alone, it will take millions of years to melt that ice. You need something else, and the only available storage of this size of energy is the oceans. The second point is, we have literally no clue what makes the oceans behave the way they do. the last millions of years they have had cycles with ice ages coming and going. They have done this without any humans having lifted a finger. What mechanisms will tap the energy out of the oceans? what will happen to the oceans when all this energy is tapped? These are mind boggling processes that not a single person has an answer to, and never will. The earth isn’t a steady state system. It is evolving to something it has never been before all the time. Sometimes continuously, gradually, sometimes catastrophically.

Airborne_Again wrote:

So you’re saying that essentially all the climatologists in the world don’t know what they’re doing, but you do?

No, but you are touching the issue. The climatologists say there is a small chance global warming could melt the Greenland ice. After all, how the obviously unstable/cyclic-looking oceans react to a few degrees heating of the atmosphere is unknown. We can assume it will react somehow, but exactly how, and to what magnitude? no one knows. But, anything is possible, even though the chance might be less than one in a billion. Then the politicians say we need to do something, or the Greenland ice will melt, because the climatologists have said this is a likely event. “We” admit “we” don’t know for sure, but better to be safe than sorry. We have to think about future generations and bla bla bla.

A possible, yet highly unlikely effect of the atmosphere heating, that are known to have happened without human intervention whatsoever, is transformed into a “moral” dilemma. It’s transformed into a choice of being “good” or “bad”. It is transformed into a belief system that say: If we are good with nature, then nature will be good with us (and of course the opposite, if we are bad with nature, then nature will bite back). This has nothing do do with science, it’s 100% religion. This religion “makes sense” though, it’s basically what all religions deep down are all about: be a good human being, and you (and your children, and their children …) will be rewarded. Be a bad human, and you will be punished.

Interesting, Archer-181, thanks for posting.

I find it very frustrating we (as mankind) don’t seem to know what’s ahead, and whether we can really make a difference or not. Even the often quoted ‘97% agreement among scientists’ is debated. And even if you take that number, our models are probably flawed.

Then again, suppose the chance is only 25% that we head towards very dire consequences. Would that not be enough reason to do something? Let me bet that 99% of you have insured your home against fire. So what’s the chance of that happening? That percentage probably starts with a decimal.

Plus it is demotivating if one starts to think that it all doesn’t really make a difference whatever we do.

Luckily there is one factor that very few people will be able to deny which comes to the rescue. And that is that we’ll be running out of oil, or it becomes economically unviable to extract it. The current consensus seems to be 50+ years, which is really not that long if you think of it. And, in the meantime, the sooner we can liberate ourselves from shady regimes that dominate the wells the better.

So the energy transition needs to continue, and fast. Conventional nuclear should not be off the table, as a bridging source. Nuclear fusion should receive a funding boost. And i’m afraid relaying on the good intentions of people is not enough. To few bother. Our oil addiction will mean making green energy cheaper and taxing the black stuff.

Where the heck is my electric plane?

Last Edited by aart at 20 Apr 08:28
Private field, Mallorca, Spain
355 Posts
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