Friday 12 June 2020

There's a Hole in My Bucket, Theory

From Hansen et al, 1981, page 6, column 3

We get the analogy of the leaky bucket: A bucket with a hole in it has water running into it at a constant rate and leaking out through the hole at the same rate, meaning that the level in the bucket remains the same. If the hole is made smaller, the level of the water in the bucket rises until the pressure is such that the flowrate of the water out through the new, smaller hole once again matches the flowrate of the water entering the bucket.

The bucket represents the Earth's atmosphere, the incoming water is incoming solar radiation and the outgoing water is heat radiated back from the Earth into space. The hole represents the Greenhouse Effect (GHE) controlling the outgoing radiation. As the CO2 levels in the atmosphere increase, so the GHE increases and outgoing radiation decreases. This is represented by the hole getting smaller. More heat retained causes the temperature to rise, and this produces more outgoing radiation until the equilibrium is re-established, just as the water level in the bucket settled down to a new, higher level.


Now the problem with this analogy is the same holds true for a change in the amount of water entering the bucket, assuming the hole remains the same size. More water coming in means that the level rises, less means it falls, therefore an increase in solar energy reaching the Earth would cause a temperature rise, a decrease a fall. However, this is not borne out by observations. From that ever-useful site, Skeptical Science, we find this graph:



This quite clearly shows that the amount of incoming radiation from the sun has been falling since about 1980. Up to that point, once you allow for a lag between increasing solar radiation and atmospheric temperature, there is a strong correlation between the two. After that there is none.

The only possible explanation is that the GHE only really kicked in around 1980, however a glance at CO2 levels over time, while it shows that the rate of increase of CO2 went up after 1960, does not show an increase that would account for almost zero affect up to 1980 and sufficient effect thereafter to cause warming despite a fall in the intensity of incoming solar radiation.

So either the rise in the water level in the bucket is due to more water coming in, which would be correct up to 1980, or it is because the hole is getting smaller, which would be correct from then on, but it can't be both.

15 comments:

Mark Wadsworth said...

B, I have read the Holy Texts and can assure you that increases in temperature are always solely to do with CO2 (there is never another reason) and falls in temperature are either due to natural factors (sun dimming, volcanic dust) or aerosols/pollution, which mask the 'underlying warming trend'. So go to the bottom of the class.

Mark Wadsworth said...

... and if solar activity hadn't been falling, we would have had two degrees of Global Heating since 1980, just as our Great Prophet St James of Hansen predicted.

Bayard said...

Top hand-waving there!

Your first comment reminds me of the handwriting expert from the Dreyfus trial, who said that where the handwriting on the treasonous document matched Dreyfus's, it showed that he had written it and where it didn't it showed that he was trying to disguise his hand.

Mark Wadsworth said...

The Consensus agrees that Dreyfuss did it, like in a jury trial with an 11-1 majority guilty verdict. What's your problem with that?

Brian, follower of Deornoth said...

Off topic, but have you come across this...

https://twitter.com/AlaskanCourtney/status/1271794446024105984

Mark Wadsworth said...

BfoD, cow attacks are never off topic! Thanks.

Mark Wadsworth said...

B, also that graph is worthless. A change in W/m2 from 1361 to 1360.5 would only change surface temps by 0.0001 degrees or something.

Bayard said...

Mark, well it is from Skeptical Science, what do you expect?

Mark Wadsworth said...

B, that's not what I meant. They shouldn't even have stooped to showing that chart, the W/m2 axis should show W/m2 ^ 0.25, emphasising that such minor changes wouldn't make much difference to temperature either way. One-nil to them on this topic.

Bayard said...

Well, something is causing the Earth to warm up, as we head out of the Little Ice Age, presumably the same thing as caused it to cool down in the first place. We know it's not CO2, that's just twisting around cause and effect, so what is it? AFAIK, Mars is warming, too, but the Consensus don't like to talk about that.

Mark Wadsworth said...

B, what is it? We'll never know.

Bayard said...

We already do http://gulfcoastcommentary.blogspot.com/2013/11/what-causes-ice-ages.html
There is, of course the standard disclaimer at the end, otherwise the blog author would be in line from a visit from the Inquisition and being put to the Extraordinary Question (which isn't, "why didn't everyone see through this guff decades ago, BTW). Note the discrepancy between the disclaimer and the actual ice core records.

Mark Wadsworth said...

B, yes, we're agreed on what causes (proper) Ice Ages. And roughly, why they end.

What we can't explain is minor temp fluctuations of +/- 1C since the last Ice Age ended about 11,000 years ago. Roman Warm Period, Dark Ages etc.

That is not the issue, the bit that upsets me is that the Alarmists blame all 33 C of "greenhouse effect" on GHG, even though it is obvious it is just the atmosphere converted potential to kinetic energy [and back again].

If they conceded on the + 33C, I'd be happy to concede on the +/- 1C.

Bayard said...

"I'd be happy to concede on the +/- 1C."

I wouldn't. It's the +/-1C that is being used as justification for all this "green crap", as David Cameron so memorably put it.

Mark Wadsworth said...

B, details, details. The Consensus says the entire 33C is due to GHG, which makes it easy to justify an extra 1C on the basis of "a bit more GHG".