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Messages - Simon

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1
Arctic sea ice / Re: 2020/21 Freezing Season Predictions
« on: September 29, 2020, 08:20:02 AM »
I predict volume to be 20,000km3 at maximum.

2
Arctic sea ice / Re: The 2020 melting season
« on: September 18, 2020, 09:13:43 AM »
Oren’s figures are very interesting. Seems that seasonal ice loss is 17.5 x 1000km3 +/_ 10%. We will have to wait till the late September volume result is in but it is likely that 2020 may become the 2nd largest volume loss of recent years.

One may like to speculate that a potential BOE (however defined) may need a precondition of a maximum ice volume below 20 x 1000 km3

3
Science / Re: Carbon Cycle
« on: September 06, 2020, 08:25:41 AM »
Interesting paper. Not sure why or how there is such a huge variation in the ocean sink in the past twenty years. ????

The conventional wisdom has been that the oceans have been sinking 2.5PgC per year As this paper assumes

https://essd.copernicus.org/articles/11/1783/2019/essd-11-1783-2019.pdf

This paper may have the best carbon cycle illustration I have seen (page 5)

4
Policy and solutions / Re: Renewable Energy Transition and Consumption
« on: September 05, 2020, 09:06:21 AM »
Solar PV and offshore wind can provide the world’s energy requirements. We need 300 to 400,000km2 of mainly sunny desert for solar PV and between 1/2 and a million turbines. The shortfall can be provided by hydro, nuclear, geothermal etc. If there is a need for limited hydrocarbon fuel then these can be provided by synthesis via atmospheric co2 and water as I pointed out in a previous post.

The Arctic icecap can be saved and so can human civilisation. There technological and economic means are there. It now needs the political will.

5
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: September 02, 2020, 07:53:51 AM »
I could well be wrong but when I thought about BOE, I came to the conclusion that 2027 +/- 2 years would be when an annual BOE would become a permanent feature and that the length of time this would persist would increase perhaps as much as several months by 2050.

6
Policy and solutions / Re: Renewable Energy
« on: September 02, 2020, 07:45:55 AM »
It is obvious that humanity needs to ensure that atmospheric co2 does not rise and indeed there is a need for it to fall. There has been an explosion of ideas recently about how to achieve this. I find the idea of synthetic manufacture of hydrocarbon fuel intriguing but I have severe doubts about its efficacy. However, at least it may save us from the madness of biofuels which would need very approximately an area three times the size of the US for it to supply our energy needs.

My idea has for a long time, been to consider use of our sunny deserts for a mass coverage of solar PV, combined with half a million perhaps up to a million offshore wind turbines, as our primary source of energy. Intermittency is a huge problem however, but one that is being thoroughly discussed on this thread, but pumped storage and battery storage has its limits IMO.

Back to synthetic hydrocarbons.

A good review is here for you all to read!

https://royalsociety.org/-/media/policy/projects/synthetic-fuels/synthetic-fuels-briefing.pdf




7
Arctic sea ice / Re: The 2020 melting season
« on: September 02, 2020, 07:31:00 AM »
Is it me or does the ice have the shape of a dog with a Beaufort tail?

8
Policy and solutions / Re: Renewable Energy
« on: August 28, 2020, 08:51:51 PM »
Thanks for link. Pumped storage is becoming an important player in buffering the supply and demand inconsistencies. Large scale battery storage as advocated by Musk I am not sure about especially if the demand is large. The intermittency problem though can and will be overcome and vast solar PV arrays will have their day I am sure.

9
Policy and solutions / Re: Renewable Energy
« on: August 28, 2020, 08:48:59 AM »
You might like to read about Dinorwig pumped storage in North Wales.

https://en.wikipedia.org/wiki/Dinorwig_Power_Station

Impressive

10
Science / Re: Sea Level Rise Accelerating
« on: August 24, 2020, 01:07:09 PM »
For an overall view of sea level rise, the Americans have a good site here:

https://www.climate.gov/news-features/understanding-climate/climate-change-global-sea-level


11
Science / Re: Ocean temperatures
« on: August 23, 2020, 08:44:21 AM »

12
The forum / Re: Forum Decorum
« on: August 15, 2020, 08:26:58 AM »
I think you get a more considered and informed interpretation of data and also opinion on this forum that you would otherwise get on social media platforms.

Keep with it!

13
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: August 12, 2020, 08:43:56 PM »
May not be the right thread but as Arctic summer sea ice is being referred to, the latest modelling indicates circa 2035 for its first disappearance.

https://www.sciencedaily.com/releases/2020/08/200810113216.htm


14
Consequences / Re: COVID-19
« on: August 12, 2020, 01:12:55 PM »
Covid has so far the impact of about double a very bad flu season and a very bad flu season causes the health care system serious problems.

I am very impressed by how much social and personal behaviour has had on reducing infection and hence death rates. This has probably been our saviour.

I am also very impressed to the extent in which social and personal behaviour is having on reducing deaths from other causes eg air pollution, traffic accidents and communicable diseases. So much so that Germany does not have an excess death death rate problem.

Covid will continue to harass our economies and behaviours until an effective vaccine can be found.

15
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: August 07, 2020, 08:09:29 AM »
The rcip pathways are based on the total greenhouse gas radiative forcings which now stand at about 3.2W/m2 or so. I think I am right in saying this.

16
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: August 06, 2020, 09:42:30 PM »
But isn’t the total greater than that, about 3.2W/m2 ?

https://www.esrl.noaa.gov/gmd/aggi/aggi.html


17
Arctic sea ice / Re: The 2020 melting season
« on: August 06, 2020, 09:34:09 PM »

18
This is fun

20% chance of 2012 record being obliterated

60% chance of new record low but only just

20% chance of a new 2nd place narrowly failing to beat 2012

19
The forum / Re: Forum Decorum
« on: July 19, 2020, 06:26:41 PM »
I am mostly a lurker and I find the data produced to be very informative. For me personally, it is often too detailed but that is just me. I hope that those who do all this hard work do not become put off by sniping comments which I find unnecessary. IMO if any poster feels there is room for improvement then let him or her make some improvements rather than snipe at other people’s efforts.

20
Arctic sea ice / Re: The 2020 melting season
« on: July 17, 2020, 07:47:12 PM »
Melt pretty much stops the last week of August when insolation is at half the solstice-max. Three weeks later, in mid September, insolation hits ZERO.

Melting in the dark is a big NOPE.

I wonder what Friv would say about this. Like was mentioned few pages ago:

I am starting to think that the real wonders will come after September-October. All that insolation had to warm up the seas very much and it will take a very long time for them to cool down. We could see a very late freezing season with a steady low pressure system and plenty of clouds...
Yes, probably a jump start above 80N into the freezing season and then a painfully slow freeze in increments, depending on the weather.

with such thin ice that late, FRIV's idea of a partial november re-melt becomes a possibility as well.

November re-melt - probably some space mirrors channeling summer sun all the way back? ;D

Further, back in the old days, and i mean really old days, geologically - Arctic was ice-free 24/365 with crocodiles (who just can't live in freezing water) happily inhabiting the waters. Last i heard, Earth was still going same 40000-year cycles between 22...24.5 tilt. Means same polar night as we have today.

I hope you won't try to convince us it's modern paleontologists who secretly transported crocodile fossils into the Arctic to make some sensation in some journal for "discovering" 'em...  8)

edit: oh and this is not discussing this melt season minimum date a slightest. That's me protesting against unacceptably wrong statement - and made in CAPS at that.  >:(
No idea how a reference to the Eocene is relevant to the 2020 melt season except perhaps it demonstrates that Arctic regions can go ice free with an 8C higher temperature.

21
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: July 16, 2020, 08:17:17 PM »
Thanks for that. I am pessimistic however that governments will institute the policies necessary even for a RCP4.5 scenario.

We have to close down all use of gas, oil and coal in a very short timeframe, twenty years or so. The zero carbon emitting alternatives exist and are plentiful. No problem now with the technology. It’s just government who stand in our way.

22
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: July 15, 2020, 09:12:58 PM »
Given that the RCP values refer to radiative forcing of all greenhouse gases in 2100, and given that the rf value now is 3.2 And assuming a steady increase as seen in recent years, the nearest pathway is RCP6.0.

RCP8.5 was imagined as a very high end scenario but one which is not actually impossible but one that would depend upon increasing greenhouse gas emissions and a huge failure of our main CO2 sinks, namely biomass and oceans.

23
Permafrost / Re: Toward Improved Discussions of Methane & Climate
« on: July 15, 2020, 08:57:46 PM »
Radiative forcings of CO2, CH4 and other greenhouse gases are given towards the bottom of this page

https://www.esrl.noaa.gov/gmd/aggi/aggi.html

CH4 is about a 1/4 that of CO2


24
Arctic sea ice / Re: The 2020 melting season
« on: July 14, 2020, 06:30:00 AM »
So is the consensus that the sea ice will end up like 2012 but with the edges severely trimmed? A record low with a lot of ice free ocean but no Blue Ocean Event?

25
Policy and solutions / Re: Renewable Energy
« on: June 15, 2020, 08:00:35 AM »
I would like to see a massive and rapid expansion of solar PV installation, worldwide preferably 20 000km2 each year for next twenty years. Plenty of sunny desert available. Install a million offshore wind turbines and the carbon emissions from energy use becomes completely resolved.

26
Policy and solutions / Re: Coal
« on: June 14, 2020, 08:38:01 AM »
Obviously, all carbon emitting power generation has to go (including biomass) and go quickly. The main primary providers need to be solar PV and wind with hydrogen as a buffer for intermittency and very useful fuel especially for planes. Hydro, nuclear, geothermal, ocean wave and current can make a useful contribution but wind and solar have to be the main providers. For Europe, perhaps consider each country covering 1% of land area with solar PV and in addition having 200,000 wind turbines in the North Sea and elsewhere for common sharing.

For a whole world strategy, I’ll think you’ll find that 400 000 km2 of solar PV would serve us all well which is a fairly small fraction of the planet’s sunny deserts. The intermittency and daily and annual variability problem can be resolved by hydrogen generation for a transportable fuel.

27
Arctic sea ice / Re: Arctic energy balance
« on: May 30, 2020, 07:41:37 PM »
Of course, we need to remember than the Arctic energy budget may not be typical for the planet as a whole as radiative emissivity varies with temperature, T^4 in fact. Thus a lot less radiation escapes into space than elsewhere on the planet.

28
Arctic sea ice / Re: The 2020 melting season
« on: May 27, 2020, 05:49:48 PM »
Re my post on additional heat transfer from solar irradiation due to reduced albedo. I assumed sea ice to be very close to 0C on June 1st and I assumed no cloud cover which Phoenix kindly pointed out is not correct. Assuming clouds reduce incident radiation at the surface by half then I consider it safe to assume an additional 60W/m2 could be absorbed by sea ice in the event of zero snow cover. Thus 40x24x60x60x60 being the number of joule absorbed and dividing this by the specific latent heat of fusion of ice being 336000J/kg gives about 600kg of additional ice melt per m2 which corresponds to a 60cm reduced depth by mid July. Interesting I think.

29
Arctic sea ice / Re: The 2020 melting season
« on: May 27, 2020, 12:08:50 PM »
Given that an unusual reduction in albedo Is anticipated from 0.9 to about 0.65 over the period of 40 days when solar insolation is 500W/m2, I wonder if anyone has done an estimate of how much extra reduction in sea ice thickness will be caused by this? My own back of envelope estimate suggests about a 1cm extra reduction for each 1W/m2 of heat energy transfer. Theoretically, the sea ice could thin an extra 1.25m! That would mean the oft quoted BOE in August / September. Have I done something wrong? Loss of snow cover cannot have that large an effect surely?

30
Science / Re: Magnitude of future warming
« on: September 27, 2019, 08:32:29 AM »
Excellent work by Gerontocrat into carbon sinks. However, I am surprised to find the quantity in gigatonne of carbon sunk being on the same axis as percentage sunk given that total emissions are not constant.

31
Walking the walk / Re: Heating with wood or pellets ? and air heat pump ?
« on: September 20, 2019, 04:36:27 PM »
According to this Finnish study, log burning is not good for the climate. Pellet burning is far better. The best method of home heating is heat pumps powered by zero carbon electricity. Trouble is, heat pumps only work well in well insulated houses.

https://www.sciencedirect.com/science/article/pii/S0301421519304161


32
Consequences / Re: Prepping for Collapse
« on: September 10, 2019, 12:20:59 PM »
We need to source our primary energy in such a way that does not increase atmospheric CO2 levels. This is actually quite easy compared with mining coal, extracting oil and gas.

33
Policy and solutions / Re: When will CO2 emissions peak?
« on: August 12, 2019, 06:42:28 PM »
Simon:
Why within months, if they haven’t realized after decades?
Whilst some governments have declared climate emergencies, they do not appear to realise they need to act upon it. Even the UK seems hell  bent upon a fracking programme for gas extraction. This needs to stop and a zero carbon energy infrastructure needs to be developed and quickly.

34
Policy and solutions / Re: When will CO2 emissions peak?
« on: August 12, 2019, 02:13:24 PM »
What needs to happen is that the world stops increasing atmospheric co2 mainly by the cessation of fossil fuel burning by around 2040. Otherwise we will be tracking somewhere between rcp6 and rcp8.5 and human civilisation will experience a disaster well before the end of this century.

We use an energy production capacity of about 20TW and we can meet that with zero carbon emitting sources. The one which can be quickly installed in large numbers is solar PV. 400 000km2 on rooftops, pontoons and in sunny desert areas would provide well above half of our consumption. Buffering, storage and transport are only a slight technical problem. We can do it and governments will realise within a matter of months that they will have to.

35
Science / Re: Has climate sensitivity been under-estimated?
« on: August 08, 2019, 08:08:36 PM »
Water vapour has an amplifying feedback of 2.7 based upon its temperature dependent radiative forcing value of 2.2W/m2. RF at 2xco2 preindustrial value is 3.7W/m2. Add the effect of the other well mixed greenhouse gases eg methane, n2o, SF6 and an approximate total could be as high as 5.5W/m2. Times this by the H2O amplifier to get about 15W/m2. This this RF value by the well known 0.31 to get temperature rise and we have an increase in temperature of about 4.6K. However, there are a number of feedbacks which could alter this value, albedo, change in land use, aerosols, clouds so nobody really knows what will happen.

36
Greenland and Arctic Circle / Re: Greenland 2019 Melt Season
« on: August 03, 2019, 09:08:42 AM »
Although the vast ice sheet actually gains ice over the year, there is a net loss of ice mass through an accelerating glacier loss as demonstrated by this thorough review.

https://www.pnas.org/content/116/19/9239

Greenland has been causing a sea level rise of 0.3mm a year. I just wonder what this value is going to increase to in the coming decades?


37
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 15, 2019, 03:24:04 PM »
When the Arctic goes very low early September looks as though it depends upon the volume at maximum. It seems that if the max volume is below 18 000km3 then there is a good chance of a BOE occurring. Then in any given season, the rate of ice loss would depend upon weather, insolation etc. So, perhaps a September virtually ice free arctic may depend on poor autumn winter recovery. Does this make sense?

38
Policy and solutions / Re: Renewable Energy
« on: July 09, 2019, 12:57:39 PM »
To protect the biosphere and human civilisation, we need to stop increasing atmospheric CO2. This means not using oil, coal or gas from fossil sources to make energy. Electricity produced from solar PV, wind turbines will need to feature on a large scale but are eminently viable. 400 000 km2 of solar PV can provide humanity’s entire energy consumption.

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