[Petrochemicals]

Well, maybe Trump can put some pressure on them to educate ordinary people in the tremendous advantages of having small families;

You mean trumpf of multiple wives, Trumpf of the multiple children, trumpf of the Republican Christianity?

[acsinuk (OP)]

On the assumption that Trump/Musk can sought out the UN to give free family planning aids will reduce CO2 emissions and limit climate change as the fertility rate will be under 2 everywhere so children will be secure, by inheriting houses from parents.
From the planets point of view and best economics option; it would be convenient if people died off once they are no longer working; as we all will die in the end that is for sure.
Voluntary euthanasia for people over 75 should be encouraged in all civilised countries which will assist the NHS and paramedics there hugely.   What is the point of keeping someone over 90 alive to suffer longer, when there is no chance of them ever being able to look after themselves at home??

[Bored chemist]

On the assumption that Trump/Musk can sought out the UN

They won't; it's not profitable for them.

"Voluntary euthanasia for people over 75 should be encouraged "
Can Donald Trump (78) lead by example please?

Do you see now how, once you start "encouraging" euthanasia , it is no longer voluntary?

Please stop posting that sort of thing.

[alancalverd]

Voluntary euthanasia should be available to everyone, not just the old. But that won't solve the problem of thirst and starvation for the next 20 - 30 generations.

I'm somewhat baffled by Trumpf. In a nation where every citizen has the right to buy a precision automatic sniper rifle with his weekly groceries, how could anyone fail to kill an incontinent overweight fascist standing on a stage at 100 yard range? 

[Bored chemist]

which was higher, and just as irrelevant, 240,000 years ago and several times in between.

You keep saying that, but...

"Measurements from older ice cores (discussed below) confirm that both the magnitude and rate of the recent increase are almost certainly unprecedented over the last 800,000 years (Fig. 2). The fastest natural increase measured in older ice cores is around 15ppm (parts per million) over about 200 years. For comparison, atmospheric CO2 is now rising 15ppm every 6 years."
from
https://www.bas.ac.uk/data/our-data/publication/ice-cores-and-climate-change/

Where's your data about rate of change of temp?

[alancalverd]

A competent scientist such as yourself can interpret rates of change from a graph. An experienced scientist such as myself recognises that sampled data cannot give you an accurate measure  of instantaneous rate of change at any point in the past. A logical scientist, or even a lawyer, would ask whether you think that current temperature depends on the rate of change of [CO2] or the recent value of that parameter. 

[paul cotter]

I have seen convincing arguments from both sides, ie those who say the temperature rise is associated with fossil fuel use and those who say it is not. As a result I am sitting on the fence as I am not competent to analyse such a complex problem(hope I don't get splinters in my derriere!!). Whatever the truth I cannot see anything being done about it. Basically we have two government systems on this planet, dictatorship and democracies(democracy called by Churchill as not the best system but the least worst). Dictators only care about themselves and are not concerned about the environment. In democracies the rate of reduction in fossil fuel use demanded by the climate scientists would raise the cost of living so much that no government employing these measures could hope to survive and would soon be replaced by a populist right wing outfit.

[alancalverd]

The current rise in temperature began at least 20,000 years ago when the entire human population numbered about 1,000,000. The graph of both temperature and [CO2] looks almost exactly the same as it did 120,000 years earlier and in at least two previous cycles to that. 

I will leave it as an exercise to the reader to propose a causal relationship based solely on the scientific evidence attached hereto.

But the important question is what are you going to do to protect the next few generations from the medium-term effects? Given the half-life of atmospheric CO2 of 120 years, and the fact  that up to 300 ppm is inevitable, I don't see that things would get any better for our grandchildren if we all stopped using fossil fuels tomorrow.

[paul cotter]

If we stopped using fossil fuels tomorrow I believe our grandchildren would starve.

[alancalverd]

Unless we have fewer grandchildren and defend the land they live on.

I live on what used to be (until about 1950) a horse-operated farm, and I don't think the families that owned it for the previous 500 years actually starved. Indeed they, and a farm the other side of the river, managed to feed a thriving village and still export barley to London brewers. 

[paul cotter]

Agreed, in the case you have illustrated. What percentage of the British people live in similar circumstances? Quite a small percentage, I would reckon. Or put another way what population do you think could be sustained with horse powered agriculture?

[Bored chemist]

A competent scientist such as yourself can interpret rates of change from a graph. An experienced scientist such as myself recognises that sampled data cannot give you an accurate measure  of instantaneous rate of change at any point in the past. A logical scientist, or even a lawyer, would ask whether you think that current temperature depends on the rate of change of [CO2] or the recent value of that parameter. 

We are still waiting for the "experienced scientist" to demonstrate that they are competent.
In particular by explaining how a rise in CO2 could fail to produce an increase in temperature.
I'm not saying it's linear, nor am I saying that there aren't positive feedback mechanisms.

[alancalverd]

Where did the CO2 come from so suddenly, and go to so slowly, in previous cycles? There's no in-phase cyclic volcanic mechanism (and certainly no evidence of a sudden increase in volcanism at the end of the most recent ice age)  or evidence of regular cometary impact (which would produce an even sharper rise in whatever).

Remembering that most animal biomass was coldblooded until the last 1000 years,  you can postulate a simple mechanism where temperature determines the plant/animal balance and hence [CO2] and the inherent positive feedback of the [H2O] cycle then produces the observed phenomena.

Anyway, such a discussion is not even fiddling whilst Rome burns - it's arguing about who made the fiddle! The question is, what are we going to do about ten billion people inhabiting and polluting a planet that can only sustain a tenth of that number at best?

[alancalverd]

Agreed, in the case you have illustrated. What percentage of the British people live in similar circumstances? Quite a small percentage, I would reckon. Or put another way what population do you think could be sustained with horse powered agriculture?

Best estimate is not to use horses (which emit more CO2 than tractors!) but to move to renewable electricity and hydrogen storage. That will sustain about one tenth of the present population of these islands in the present level of comfort, indefinitely.  Most of the rest of the world is doomed. 

[Bored chemist]

Where did the CO2 come from so suddenly, and go to so slowly, in previous cycles?

Who cares?
Do you recognise that today's situation is different from those?

[Petrochemicals]

Where did the CO2 come from so suddenly, and go to so slowly, in previous cycles?

That is a point Alan, you would expect that the earth would run out of surface carbon with the chemical reactions and sedimentation. I know there is carbon in volcanism but the amount is only very small.

[alancalverd]

Who cares?

I care.

Mao Tse-Tung said "It is well known that when you do anything, unless you understand its actual circumstances, its nature, and its relations to other things, you will not know the laws governing it, or how to do it, or be able to do it well".  (Selected Works, Volume 1, p179, 1936)

I have a suspicion that the laws of physics haven't changed in the last 400,000 years, so it's important to  know why it happened the last four times, and also why the present trend began long before humans exploited fossil fuel to any significant extent.

[Bored chemist]

OK, long ago, volcanoes melted rocks.
Today, mankind smelts steel.

The first process has very little to do with the second one and no matter how much you study vulcanology, it tells you very little about ferrous metallurgy.

The events that caused the ends of ice ages may be nothing like the event that we are causing.

[alancalverd]

The challenges remain.

1. If CO2 drives climate change,

(a) where did it come from in the past

(b) where did it go to

(c) why did the [CO2] curve lag behind the temperature curve

(d) why are the historic cycles of [CO2] and T bounded so tightly

(e) why are the cycles so regularly periodic?

Hint: the answer to (a) is nothing to do with volcanoes - there's no consistent correlation with ash deposits.

Now on to the serious stuff:

2. Whatever the answers in 1 above, global climate change is already harming humans, so if you can't prevent the cause, or if it's too late to do so (given that the half life of atmospheric CO2 is at least 120 years) , what are you going to do about it?

3. If the cause is anything to do with fossil fuels, what do you propose to replace them  without making things worse during that transition?

[alancalverd]

no matter how much you study vulcanology, it tells you very little about ferrous metallurgy.

Which raises an irrelevant but entertaining question for BC and any other chemists or geologists hovering around this forum! I have a suspicion that volcanic gases are mostly reducing rather than oxidising. So is lava more or less oxidised than the metals in the earth's crust and mantle?