Monday, June 02, 2008

A bucket of woe for alarmists

The alarmists seem to be increasingly desperate to find anything that disputes the "climate change is natural" theme - and judging by this latest effort reported by the Independent they are really scraping the bottom of the barrel. Or should that be bucket?

Scientists believe they can now explain an anomaly in the global temperature record for the twentieth century, which has been used by climate change sceptics to undermine the link between rising temperatures and increases in atmospheric carbon dioxide.

The record for sea-surface temperatures shows a sudden fall after 1945, which appeared to go against the general trend for rising global average temperatures during the past century.

Well, no - it didn't "appear" to go against the trend, it DID go against the trend and, despite the headline claiming this new "study" has "discredited" a significant anomaly, it doesn't dispute the fact that there was a very real cooling period between the 40's and 70's at a time when CO2 emissions were at their peak.

Anyway, the main thrust of their argument is this .......

[A]n international team of scientists has investigated the raw data from the period. They found a sudden increase from 1945 onwards in the proportion of global measurements taken by British ships relative to American ships.

Uh huh. So?

The scientists point out that the British measurements were taken by throwing canvas buckets over the side and hauling water up to the deck for temperatures to be measured by immersing a thermometer for several minutes, which would result in a slightly cooler record because of evaporation from the bucket.

How do they know? They weren't there when this was being done, they did not conduct experiments at the time to see if there was a "slightly cooler record" so what this team have actually done is .... guess.

The preferred American method was to take the temperature of the water sucked in by intake pipes to cool the ships' engines. Those records would be slightly warmer than the actual temperature of the sea because of the heat from the ship, the scientists said.

What heat from the ship? These are INTAKE pipes - not exhausts. A ship doesn't generate heat - it's a fucking great lump of metal and probably a darn sight colder than the water it is pushing through!

This study is absolute crap and they know it. Do they know if the canvas buckets were drawn up in the shade or in direct sun? How much water does each bucket hold. How much colder will it get sitting on the deck for a few minutes?

The most remarkable thing about this study in assumption and guesswork is that it somehow managed to get published in Nature magazine - a once respectable scientific journal. That, if anything, tells you more about the politicisation of science than anything else.

Does the study really discredit - as the Independent asserts - the fact that cooling took place between the forties and seventies? No - the only thing this study discredits is science itself.


Anonymous said...

What heat from the ship? These are INTAKE pipes - not exhausts. A ship doesn't generate heat - it's a fucking great lump of metal and probably a darn sight colder than the water it is pushing through!

What's your basis for saying this?

If you put a lump of metal in a bucket then leave it, the water and the metal will eventually share the same temperature. If the metal is initially hotter then it will heat the water whilst the water cools it; and vice versa. The ship itself has sources of heat. The engines and heating inside the crew areas, for example. These will tend to heat the ship while the sea water cools it. The net result is that inside inside the ship it will warmer than outside.

Pumping water into a ship will tend to heat it a little as will being stored inside the ship. If the temperature was taken immediately upon loading then it would be different than if the water was stored and then measured.

It's true that the canvas buckets would suffer evaporation lowering the temperature. However evaporation is dependent upon surface area. It's not clear what happened to the water after it was brought up. If it were placed in a closed container then evaporation would soon end through saturation. If the water were emptied into an open bucket, then it would evaporate but at least have a fixed surface area proving consistency. If it were left in the canvas bucket then the surface area may vary upon each measurement. Further, it's not clear from the article that the buckets were always lowered to the same depth of water alongside the ship. This would create a problem since water temperature varies by depth. It's assumed that the measurers took precautions to avoid the problem that a ship expels hot liquid from certain points around the hull.

In an experiment like this the important requirement is for consistency. There's nothing inherently wrong with any method provided it is repeated, exactly the same, day after day. After all if the measurements were half a degree too high in 1945 then the same method would yield half a degree too high today. We would know the change in temperature which is all we want. If a new "better" method of measurement becomes available, then it shouldn't immediately supercede the old; the correct approach is to continue old and new methods side by side until sufficient data is gathered to estimate the potential error of the old data series. In this case we have differing tests carried out concurrently. I would isolate method A from B and compare the results. One set should be consistently higher than the other but both should yield a similar curve. I don't see any of this discussed in the Independent, who seem suspiciously keen to trumpet it's supposedly skeptic destroying conclusion. The Independent has long since ceased to be a serious newspaper, preferring instead to be a purveyor of End Times sermonising.

The net result is that whilst I share your suspicion, I can't dismiss the actual science study. You should note that the man who discovered the flaws in the Hockey Stick, has pointed out the same problems with the measurement two years before. See also here.

The overall lesson is that science is on the side of the sceptics. The reason that the warmists appear to dominate is that they dominate the media and bodies like the UN. Don't dismiss ANY science unless you are sure.

Stan said...

My basis for saying that was the understanding that metal has little capacity for storing heat, while water does - but I'm no scientist. That's just schoolboy physics.

The cold water intakes are taking water from outside the ship - so any internal source of heat shouldn't be having an effect prior to the temperature being measured.

The canvas buckets are particularly inaccurate as there are a load of other things that could affect the temperature. Is the ship steel or teak decked for instance? Is the deck in the sun or the shade? If the deck has been heated before the temperature is taken, would that not cancel out any heat loss through evaporation by transferring heat from the deck to the water? There are a number of things that could affect the temperature reading.

However, my real point was that the Independent was all too eager to claim that this study "discredited" a key argument of realists - when it does no such thing.

My other point is that this study is nothing more than guesswork and assumption with very little scientific credibility - and yet, because it has a central thrust which the alarmists would like to think proves a point (it does no such thing) it has been readily published in a respectable scientific journal when it has no right to be in my opinion.

Thanks for reading and your comments, btw.

Anonymous said...

The reason metals don't store heat well is because they are good conductors. Metal is an better conductor than water, which in turn is a better conductor than air. As we see at a blacksmith, metal cools more quickly in water than air.

It's wrong to assume that metal would stay at a different temperature than the surrounding water. It and the water will eventually reach equilibrium assuming no external forces act. The relative conductivity only affects the time it takes to reach equilibrium. Thus even if we wrap the metal in a duvet, inside a water tight bag, before immersing it in the bucket, it will eventually reach equilibrium with the water - it just takes longer.

Stan said...

I accept that the metal of the ship will reach equillibrium with the surrounding water, but I do not accept that will happen because the ship will heat the water - which is what this study is claiming may have given inflated temperature readings prior to 1945. It will happen because the water cools or warms the metal of the hull.

Nor do I accept that using the canvas buckets may necessarily have given false low readings because - as I pointed out above - there are other factors which may have cooled OR warmed the water in the bucket.

This study simply takes the statistics and then applies a number of very large assumptions to them which, in my view, is not scientific. It is guesswork - and the principle aim of the guesswork is to try and hide a significant anomaly which contradicts the AGW theory.

All I am doing is trying in my own small way to inform people that things are not as cut and dried as the MSM would have you believe.

Anonymous said...

Well, I plan to give up after this one.

Heat energy moves from hot things to cool things. Second Law of Thermodynamics. She ship (which is tiny) is heating up the sea (which is huge). Net result the sea sees no measurable rise in temperature.

I don't discount the potential errors concerning the canvas bag.

You need to understand that you are making the right argument for the wrong reasons. I gave you the links to the Bishop Hill article before. Here's another article that makes the same argument as you but for the right reasons.

The basic study showing decline in temperature after WWII may or may not be right. Assuming it is right, the conclusions drawn by the Independent et al don't follow from the result. Their alarmism needs exposing.

Contrariwise, arguing that the second law of thermodynamics doesn't apply to ships gives ammunition to warmists who think the skeptics don't understand the science.


Stan said...

Don't give up!!! ;)

Seriously, I'm not disagreeing with you or the study - I'm not really interested in the science in any great depth other than as a layman - all I'm trying to do is point out that the science has become heavily politicised. No one is going to quote me to the IPCC so if I make assessments on a study for the wrong reasons (even if my argument is correct) I'm not that bothered.

I'm just trying to bring things to the attention of other people so that they will stop accepting that the "case is closed" on AGW and start challenging some of the misconceptions and outright lies that are being offered to promote what is a very political agenda.

I am aware - through reading other articles regarding this study - that the conclusion of the study actually has negative implications for the AGW crowd - particularly the role of sulfate aerosols and how that effects their models - but these are likely to be whitewashed by the alarmists.

Anyway - thanks for your comments all the same and I hope you come back occasionally.