[Bored chemist]

is lava more or less oxidised than the metals in the earth's crust and mantle?   

Less.

[Bored chemist]

if you can't prevent the cause,

It seems likely that we can.

what are you going to do about it?

Nobody is saying that we shouldn't build sea walls and breed drought resistant crops or whatever.

But your approach seems to be that we are in a car speeding towards a wall and we can't steer. We should "adopt crash positions" + make sure the seat belts are fastened.
The rest of us are saying that's fine- but we should turn off the engine first.

The best way to make a bad situation better is to stop making it worse.

[alancalverd]

The engine will run out of fossil fuel anyway, which just adds to the problem.

Building sea walls is fine, as long as you realise that you emit around 3 tonnes of carbon dioxide for every cubic meter of concrete you construct.

Drought-resistant crops are always a good idea, as are flood-resistant crops, but sowing, fertilising, weeding and harvesting them without fossil fuels is going to require a major societal upheaval. Remember that horses emit more CO2 than tractors per tonne of crop yield. And then you have to process and distribute the stuff.

We should "adopt crash positions" + make sure the seat belts are fastened.

As you hurtle towards the ground it's always a good idea to lighten the load, unlock the doors, and tighten your harness, just in case the Hand of God doesn't intervene by suspending the laws of physics.

[Bored chemist]

Hand of God doesn't intervene by suspending the laws of physics

Like ... by stopping CO2 absorbing IR.

[Bored chemist]

Remember that horses emit more CO2 than tractors per tonne of crop yield.

So we need to run them on renewables.
OK, that's a work in progress.
https://www.biobased-diesel.com/post/built-4-business-pulling-tractor-runs-on-100-biodiesel

[Bored chemist]

Building sea walls is fine, as long as you realise that you emit around 3 tonnes of carbon dioxide for every cubic meter of concrete you construct.

Ditto.
https://www.carboncure.com/concrete-corner/a-complete-guide-to-low-carbon-concrete/

[alancalverd]

So if your tractor eats biodiesel, what do you eat? I have a friend who makes bioethanol and methane from primary cellulosic waste (straw, vegetable leaves, slurry....) but the feedstock for biodiesel is the nutritious parts of plants, principally seeds containing long alkanes - it's better to sell that as food. 

To maintain a UK lifestyle you need about 30 - 50 times as much "mechanical" energy as you consume from food. So if we were to move from fossil fuel to biofuel we would need to grow oil-rich crops enough to feed 30 - 50 times the present population. But we can scarcely grow enough to feed the people we have! 

Low-carbon concrete apparently reduces the footprint of making the stuff by about 40%, but how much carbon do you have to invest in new plant to make it, and what is the final total by the time you have transported, mixed and placed it?

And the problem with building sea walls is one of perimeter to area ratio. Quite simply, it isn't worth protecting the small islands who turn up at COP conferences, when the carbon could be better spent  protecting a large landmass like North America, China, Russia, India..... the very guys they are complaining about!

[Petrochemicals]

So if your tractor eats biodiesel, what do you eat?

Low-carbon concrete apparently reduces the footprint of making the stuff by about 40%, but how much carbon do you have to invest in new plant to make it, and what is the final total by the time you have transported, mixed and placed it?

And the problem with building sea walls is one of perimeter to area ratio. Quite simply, it isn't worth protecting the small islands who turn up at COP conferences, when the carbon could be better spent  protecting a large landmass like North America, China, Russia, India..... the very guys they are complaining about!

At 40 percent who cares ? It isn't 95% reduction. Most reducing agents come as byproducts so it is OK to a point but when the byproducts run out what then ?

And did you ever hear of king Knut?

[acsinuk (OP)]

Global warming is caused by too much CO2 in the air.  Long term effect will be polar ice melting and sea level rising.
So we need to reduce burning any fuels that produce the CO2 including wood, coal and biofuels.  Hydro-electric is good but a very limited source of energy and wind and solar good but not reliable over 24 hour periods. Nuclear power stations are  excellent but waste fuel needs to be closely guarded in safe deposits.
Most importantly we need to stop building new houses and infrastructure as this will reduce emissions of CO2 by 50% whereas electrifying transport only saves about 1%.
Anyway oil and gas reserves need protecting for our grand children so should not be used to produce electric power and heat longterm   

[alancalverd]

Nuclear power is no longer economic, and becoming less so all the time. Problem is that the fossil energy required to build and maintain a nuclear power station was such, in the 1960s, that you only got a net energy payback after 5 years of operation. I suspect  this period has now increased thanks to increased safety and security requirements (more concrete and steel!) and the construction lead time has also increased. As a result the required guaranteed price of nuclear electricity far exceeds that of any other source. Consequently there is little commercial appetite for nuclear construction and any government initiative is liable to political criticism and further waste of money on "consultancy", to be recouped from the selling price of electricity.

Apart from the manufacture of plastics (once the saviour of civilisation , now the Spawn of Satan), paint (another form of plastic,but now principally water-based) and shampoo, it is difficult to imagine what uses other than energy generation our grandchildren might find for oil and gas, so if you don't want them to burn the stuff, you might as well use it now.

Today is yet another day of low temperatures and no wind, and during the winter the British Isles also suffers long periods of little (daytime) and no (night time) sunshine, so whilst wind and solar are very attractive sources of energy, they are impractical without  a really significant (5 or 10 day) buffer store. Which we don't have, even in draft form.   

[Petrochemicals]

Solar will still not not work in this country even with storage for a number of reasons.

1) We have poor irradience, some places have 5 times (ish)our level
2)What irradience we do have is concentrated in a 6 to 12 hour window
3) 75 percent (ish) of the solar production happens in a 4 month(ish) window
4) Even wher the sun shines solar production is sporadic, we have long periods without direct sunshine.
5)direct sunshine is when the majority of energy is generated

Now if we discount the 8 months where solar production is poor this means that

1)we have to store energy for long periods
2)the solar installed capacity will have to be many many times our standard usage to cover the periods where there is no generation
3)this installed capacity will only generate at full capacity for 8(ish) hours a day so will need to be multiplied THREE more times
4)the installed capacity will reach the level that it generates enough energy in indirect sunlight (10% of potential) to sustain the country thus meaning any extra power will have to be wasted or stored. That is to say 350 gw capacity. Or at 200w per square metre 2000sqkm of panels at current uk electricity usage, separate from most home heating, transport or imported products.
5)storage capacity will need to be at 350gw so costs will be astronomical due to the over subscription, 350 gwh is half a day of uk usage.
6)if we do indeed store this energy for the winter this will mean 8 month storage capacity, whilst not being impossible is certainly more that a 15 day lull.

I seem to remember  jokes in Britian starting with "a solar powered.........", I'm sure solar powered Britian would have been laughed at years ago, wind on the other hand you would have gained agreement.

[alancalverd]

350 gwh is half a day of uk usage.

...of electricity. We also use about the same amount of direct gas and oil heating, and as much again in the form of road diesel and gasoline, so in order to fully electrify the UK's energy supply for the foreseeable future we need to generate and distribute at least 3 times as much electricity as at present, in a fully sustainable (i.e. with adequate storage for intermittent sources)  manner.

Or reduce our consumption to 10 - 20% of present demand.

[acsinuk (OP)]

Alan, using huge quantities of concrete and steel for environmental protection is wasteful and unnecessary if we sink the reactors under sea water.  Luckily, most of our UK existing nuclear plants are on the coast and ideally placed to use scaled up mini nuclear submarine technology.
Not sure of extent of Uranium deposits worldwide but Wiki seems to think Australia has plenty.
However, to reducing CO2 emissions quickly really requires responsible family planning thus reducing the need for 50% used on new buildings etc. and in the long term all fuel consumption.

[alancalverd]

The security of a nuclear submarine depends on its being in motion, in an undisclosed location, and manned by sailors and marines armed to the teeth. Somewhat difficult to connect to the National Grid.

[Bored chemist]

but the feedstock for biodiesel is the nutritious parts of plants, principally seeds containing long alkanes - it's better to sell that as food.

The easy feedstock for biodiesel is seed oils.
But there's this thing called chemistry. It lets you turn stuff into other stuff.

I have a friend who makes bioethanol and methane from primary cellulosic waste (straw, vegetable leaves, slurry....)

Well done to him (And his army of microscopic chemists).
Other fermentations are available.
https://en.wikipedia.org/wiki/Acetone%E2%80%93butanol%E2%80%93ethanol_fermentation

[Bored chemist]

using huge quantities of concrete and steel for environmental protection is wasteful and unnecessary if we sink the reactors under sea water. 

Do you really not recognise that the sea is part of the environment?

[Bored chemist]

Today is yet another day of low temperatures and no wind, and during the winter the British Isles

And while you are the one advocating sealing off the UK to block immigration, the rest of us understand that the sun is always shining somewhere. We, and France currently buy and sell electricity as required.

[alancalverd]

We, and France currently buy and sell electricity as required.

With a capacity of 1000-megawatts, the high voltage direct current (HVDC) power cable can provide enough energy to power 1 million British homes and is expected to meet 1.2% of Britain?s electricity demand.

from nationalgrid.com.
Remarkable. That presumes that each home does not attempt to cook (up to 15 kW) , boil a kettle (2.5 kW), and switch on the lights (say 200W) at the same time as watching TV (300W), using a heat pump (2 kW) , operating a refrigerator (400W)  or charging an electric car (at least 3 kW if you want to visit the supermarket before you starve to death).

Even the French electricity supply is limited and their occasional surplus comes from legacy nuclear plant, so when the civilised world becomes fossil-free (i.e.with electricity demand 3 - 4 times present levels) , the commodity price will rise to unaffordability.   

[acsinuk (OP)]

We need to reduce burning the fuels that produce that CO2, oil, gas, wood, coal and even biofuels.  Hydro-electric is good but a very limited source of energy and wind and solar good but not reliable over 24 hour periods. Nuclear power stations are  excellent but waste fuel needs to be closely guarded in safe deposits.

Global warming is caused by too much CO2 in the air.   Nature does have some naturally caused bush fires and volcanoes that do erupt and these may cause a rise in CO2 every 100,000 years or so but the current problem is caused by human beings burning huge quantities of hydrocarbon fuels.

Most importantly we need to reduce family sizes to avoid having to build new houses and infrastructure as this will reduce emissions of CO2 immediately by 50%, whereas fiddling around with electrifying transport only saves about 1%.

[acsinuk (OP)]

The long-term effects of global warming and over population are already being felt here.   
Looking at the worldometer stats per country, we can see evidence that countries that have a fertility rate of less than 2 children per family, result in the children inheriting their parents? house thus only maintenance of existing houses and infra-structure is required in these desirable countries like Sweden or Canada, with high standards of living but saving 50% of CO2 emissions used on new housing that poorer countries with 3 or 4 kids are suffering from.
Countries with 4 children per family are causing a huge housing crisis for their extra kids who will have to live in shanty towns and poverty-stricken slums. In worst cases, they will be forced to live in refugee camps with no hope for a normal future unless they can escape into a wealthy country sometimes in rickety boats or overcrowded refugee rubber dinghies.
The huge refugee camps which UNHCR is supporting, in worst cases, will turn into refugee cities which are not self-sustainable, because free food has bankrupted their farmers. Typical examples are Cox?s Bazaar and particularly Gaza.
The UN has a charter "to maintain international peace and security, uphold international law, achieve "higher standards of living" for their citizens,"       But by only supplying free medical and food aid to refugee camps and not family planning assistance, this makes matters worse like we see in Gaza at present.
Neither of the latter-day prophets, Jesus or Muhammad, advocated large families; by divine inspiration they realised that over-population could lead to a future crisis.
Before the present conflict, UN was feeding the problem in Gaza which can now only be solved by all Hamas leaders, their families and their supporters? families leaving Gaza immediately.  The UN should be paying for these thousands of families to be transported into exile in Western Sahara with its similar climate or to any other country of their choice, that does not border Israel; and in my view the sooner the better.
CliveS
 
https://www.worldometers.info/world-population/population-by-country/