Saturday, 24 December 2011

Seasonal Greetings

I've not posted for a while, but there are good reasons. I've been Excelling myself - I'll soon be posting more graphs than you can shake a hockeystick at. Australia will feature, thanks to the excellent records from the National Tidal Centre, whose SEAFRAME stations around Oz and the Pacific record climate data as well as sea-level, and show a distinct "lack of warming at the moment", to quote a now world-famous email. There are few Pacific islands which didn't show some warming from the early 1990s, but almost all show cooling since 1999. Posts on Oz and Pacific air and sea-surface (SST) temperatures soon.

I'll be updating and expanding the Pacific Sea Level post, and moving it to a permanent reference page. There'll be an Australian sea level post, also with a permanent page, and in the style of the interactive Pacific one.

In the meantime, whoever you are, and wherever you are, I surely  can do no better than give you the Vulcan four-finger salute (note the number of fingers!), and in the immortal words of Mr Spock, "Live Long and Prosper".

Monday, 14 November 2011

South Pacific Sea Level to September 2011

Note: A permanent and (to be) regularly updated page has been created (see top of sidebar) located here. I've updated this page with data to December 2011.

The island sea level charts are drawn from monthly data from the South Pacific Sea Level and Climate Monitoring Project. I've included a chart for a second Fiji station, and also one at the end for a New Zealand station, Jackson Bay (South Island). Neither is part of the project, but data is provided on the website.

The high resolution SEAFRAME (Sea Level Fine Resolution Acoustic Measuring Equipment) monitoring stations comprise modern integrated housings which measure and record sea level, barometric pressure, water temperature and air temperature. Most of the stations were installed in 1992 and 1993, though a few were later. It's important to note that the effect of local land movement is eliminated from sea level data:
The Continuous Global Positioning System (CGPS) network monitors vertical movement in the earth's crust, such as subsidence or tectonic shifts, at the SEAFRAME tide gauges and adjacent land. Sea level data can then be adjusted to compensate for the earth's movement to within a millimeter, enabling the absolute sea level to be determined. 
I have voiced criticism of Australia's Bureau of Meteorology on various topics in the past, but as far as the presentation of sea level data is concerned, I rate their National Tidal Centre as the best. The page I linked to above has a table of the 12 stations in the project (and the two others I mentioned) which links to PDF plots and data tables for sea level, barometric pressure, water temperature and air temperature. The data tables in turn link to online graphical plots and text files for easy import to spreadsheets. A map links directly to the data tables. I liked that Idea so much I've pinched it for use here.

What should be evident from the plots is that any generalisation of the situation over this wide area is invalid. Apart from an almost universal downward spike during the 1997/98 ENSO event, the history and trends differ widely. It should also be clear that claims of "25 mm/year" or "no rise" since the early 1990s are also invalid.

Most of the charts are dominated by a downward "spike" in 1997/98. The level drop was due to unusually high barometric pressure during the 1997/98 ENSO ("El Niño/La Niña-Southern Oscillation") event. The correlation is well illustrated for the Marshall Islands (Majuro Atoll), so I've placed this first. Kiribati and Tuvalu have been given much attention in the news media and on the 'net recently, so they're listed next.

Readers are welcome to reproduce any of the plots - all I ask is that attribution be given, preferably with a link to this post. I haven't used thumbnails - right-click on the image and select "save image as" or whatever your browser prompts.

Level data has been converted from metres to millimetres to overcome loss of precision in Excel's trend data. Gaps in the plots indicate gaps in the original data. Note that the trend slope is monthly - multiply by 12 to get the annual value (e.g. y = 0.2269x gives 2.7228 mm/year).

Select a location from the map to view a graph of the monthly sea level statistics for that location. Click on the bottom of the blue area for the NZ station, Click on your browser's back button to return to the map.

Lombrum, Manus Island, PNG 02° 02' S 147° 22' E Honiara, Solomon Islands 09° 26' S 159° 57' E Port Vila, Vanuatu 17° 45' S 168° 17' E Lautoka, Fiji 17° 36' S 177° 26' E Nuku'alofa, Tonga 21° 08' S 175° 10' W Rarotonga, Cook Islands 21° 12' S 159° 46' W Apia, Samoa 13° 49' S 171° 45' W Funafuti, Tuvalu 08° 23' S 179° 13' E Tarawa, Kiribati 01° 22' N 172° 56' E Nauru, Nauru 00° 32' S 166° 54' E Majuro, Marshall Islands 07° 06' N 171° 22' E Pohnpei, FSM 06° 59' N 158° 14' E Jackson Bay, New Zealand 43° 58' S 168° 37' E
Click on a red dot to jump to the relevant sea level graph
Source: Bureau of Meteorology     

Marshall Islands

Island: Majura   Location: Uliga

Note the 1997/98 ENSO "spike" and the correspondence with the abnormally high atmospheric pressure from late 1997 to late 1998 shown in the barometric pressure plot below:


Island: Tarawa   Location: Betio

The trend line is pulled down by the ENSO dip from the end of 1997 to end 1998. To give an better view of the trend from 1992 to present, I replotted the chart with that data excluded:
The resulting trend is effectively zero.
A downward trend is evident from end 2001 to present:


Atoll:Funafuti   Island: Fongafale

As with Kiribati, the deep ENSO dip in 1997/98 pulls the trend line down on the left; it's below the 1994/1997 average. A zero trend is evident from 1999 to present:

Papua New Guinea

Island: Manus   Location: Lombrum

Here's a clearer view of the 1999-2011 trend of 3.4 mm/year, slightly above the global average:

Solomon Islands

Island: Guadalcanal   Location: Honiara

Again the trend is pulled down on the left; the average level 1999 to present is around 750 mm, and the trend 2.1 mm/year.


Island: Efate   Location: Port Vila

The big 1997/98 downward spike evident in most of the other plots is absent; instead there's a relatively steady upward trend.


Island: Viti Levu   Location: Lautoka

Island: Viti Levu   Location: Suva


Island: Tongatapu   Location: Nuku'alofa

Although there's a steep trend from 1993, current levels are not dissimilar to those between 2000 and 2003.

Cook Islands

Island: Rarotonga   Location: Avatiu

Levels seem to have stabilised from 2006.


Island: Upolu   Location: Apia

The familiar ENSO dip pulls the trend down at the LHS, but there is a sharp upward "spike" from 2010.


Island: Nauru   Location: Aiwo

Overall trend is effectively flat - levels at present similar to those in 1993. However, the trend from 2002 is downward.

Federated States of Micronesia

Island: Pohnpei   Location: Dekehtik

An overall upward trend, though little change from 2007 to present.

New Zealand

Island: South Island   Location: Jackson Bay

There seems to be little overall change from mid-1998 (after the ENSO dip) to present. A plot from 1999 confirms that:

Monday, 17 October 2011

The View from a Far Country

Here's a view of Australia from “across the water” – lots of water, and not rising much, by my analysis. What I see is a microcosm of what's wrong with the world, and politics today. I see the government of a country which was built on coal, whose prosperity resulted from coal, which currently depends on coal, turning its back on it. This degree of economic and political suicide is arguably unmatched anywhere else.

I see a government which has abandoned policies which work for policies which demonstrably don't work, and can't work. I see a government pandering to a tiny minority in order to retain power. Expensive desalination plants have been, and are being built instead of much cheaper dams which serve not one but two purposes, water storage and flood control. Dams apparently “destroy the environment”, whereas clearly it's uncontrolled flooding which does that very efficiently, as well as destroying property, livelihoods and lives.

I see local authorities banning coastal development, or allowing it only if houses are built on piles, because of a projected rise in sea-level which, even if it occurs, will post-date the likely (or useful) lifespan of the buildings.

I see a government which appears to be considering “controlling” the media, presumably because they don't like contrary opinions being expressed. Shades of 1984 indeed. That same government is under pressure from Luddites who want to see a large coal-fired power station closed down, with no alternative sources of energy in place. That same government is introducing a "carbon tax" in order to reduce Australian CO2 emissions by a small fraction of a whole which itself is a tiny 1.5% of worldwide emissions. The economic damage will be tangible, the effect on world climate (even if "worst case scenarios" become reality) will be immeasurably minuscule.

I see state-funded organisations distributing exaggeration and propaganda, some would say lies (I would), about future climate and sea-level rise, in an obvious attempt to scare the population into submission. This in a country whose people's instinctive common-sense and aversion to bullshit is (or at least was) legendary worldwide.

God help Australia.

Saturday, 8 October 2011

Tuvalu - "The Economist" makes up sea-level statistics

Tuvalu, that icon of alarmists everywhere, is suffering a severe drought. The Economist explains why
Observers blame the shortage on the changing weather patterns and rising sea levels associated with climate change—and warn they could be a sign of things to come for the whole region. 
Freshwater supplies had already been running dangerously low for the 11,000 people who live on Tuvalu. The drought caused by nearly a year of sparse rainfall has been made worse [by] rising sea levels, which have contaminated the low-lying country’s underground aquifers with salt water.
As an archipelago whose highest elevation is a meagre 4.5 metres, Tuvalu feels it when the sea level climbs by an average of 5.77 mm annually. The whole country, a cluster of white sandy beaches as far as can be from the rest of the planet, is expected to disappear entirely within the next 50 years. That fate portends ominously not just for Tuvalu, but also for every other low-lying coastal area, from the Maldives to Manhattan. 
Let's see what Tuvalu is "feeling". If sea-level is rising at a rate of 5.77 mm/year, that should be readily detectable at the capital, Funafuti. Data is available to August this year (click to enlarge).

Sea-level at Funafuti, Tuvalu; Jan 1999-Aug 2011, trend -0.33 mm/year

So much for that "5.77 mm/year rise" - the trend is slightly negative. See the end of this post for details of data source. Newspapers and journals should be required to quote a source for data they include in articles and blogs. Tuvalu's "white sandy beaches" seem to be free of any immediate threat, and it would appear that the country's underground aquifers have become contaminated with sea-water due to over-extraction, not "rising sea levels".

A picture is worth a thousand words.

Sunday, 25 September 2011

Education or Muddled Disinformation and Propoganda?

From Cardiff University, where I spent some time in the 1960s:
A new bilingual educational resource developed by academics from the School of Earth and Ocean Sciences to help Welsh secondary schools deliver stimulating lessons about climate change has been launched by the Chair of Climate Change Commission for Wales.
The "pack" entitled Adapting to Climate Change in Wales is intended both for teachers, and for children at "key stage 4", that is between the ages of 14 and 16. The CU "Learning about climate change" news page continues
The Climate Change Educational Resource Pack for Key Stage 4 explains the scientific basis of climate change and explores how changes in climate could impact citizens of Wales. In particular it looks at how citizens could adapt to living in a different climate.
Aimed at pupils and teachers, the multidisciplinary pack is tailored to meet the requirements of the Welsh national curriculum. It will be distributed to at least 100 secondary schools in Wales to help teachers deliver high quality, balanced information and inspire young people to adapt their behaviour to ensure their future sustainability. Although the focus is on Wales, this packs draws on examples from all over the world and covers everyday issues such as how food supply, settlement, transport and health may be affected.
In the second paragraph, note "high quality, balanced information". How does the "pack" meet that description? Not too well, it seems. Right at the beginning of "Theme 1: The Global Climate Perspective" we find
Key learning outcomes
1. To understand key components of the greenhouse effect
2. To understand the influence of humans on climate
3. To understand predicted global climate changes
... and on the following page (page 7) is this, relating to item 1 of the "Key learning outcomes"
Principle of the “Greenhouse Effect”
The sun shines down on the surface of the earth. About half the heat naturally reflects back out into space. When greenhouse gases such as carbon dioxide and methane are released into our atmosphere, they trap heat and stop it reflecting back out into space. This causes additional warming of the earth surface, ocean and atmosphere… just like a greenhouse!
That would seem to encompass and explain precisely none of the "key components of the greenhouse effect", in my opinion. A greenhouse doesn't trap reflected heat. The glass transmits incoming solar radiation and traps the warmed air. Greenhouse gases don't trap reflected heat. The phrasing implies that they do that only when "released into our atmosphere" and not otherwise. It isn't difficult to briefly describe the essential components of the "greenhouse effect" for all 14-16 year-olds in a similarly short paragraph, though since this is intended as the scientific basis for the entire "pack", surely it deserves a longer (and accurate) description?

Sunday, 11 September 2011

Sea Level in Australia - the Inexorable Rise in Alarmism

Is the sea-level around the Australian coast rising at an alarming rate? The Australian Climate Commission would have citizens and policy-makers in Australia and elsewhere believe that it is. In their 2011 report "The Critical Decade - Climate science, risks and responses" the following map is shown (mm per year)

Figure 8. Local sea-level rise (mm/year) around Australia from the early 1990s to 2008
Looks scary, doesn't it? In the southwest, somewhere near Perth, 8.1 mm/year, implying a rise of 81 cm in a century. In the north, somewhere near Darwin, a slightly lower value. Are these figures correct? As quoted "from the early 1990s to 2008" they are, but they are also very misleading - at most of the (as yet) unidentified monitoring stations shown on that map, there has been no significant sea-level rise after 1998. I can also show that most, if not all of the rise around Australia in the second half of the 20th century occurred during 1997 and 1998. during what's been called "one of the most severe ENSO events in history". ENSO is short for "El Niño/La Niña-Southern Oscillation"  for those not familiar with the mnemonic.This is not what the Climate Commission, the CSIRO, nor the Australian government want known.

Here's my version, based on the same data, but starting from 1999, at the end of the late 90s ENSO "ramp" which grossly distorts the "early 1990s to 2008" rates shown above.

Local sea-level rise (mm/year) around Australia from 1999 to 2010
Looks rather less scary, doesn't it? Let's see where the CC got their data, and why there's such a massive difference between those two maps.

Friday, 9 September 2011

Kiribati, "where rising sea levels are a very real threat"

From the Sydney Morning Herald - Ban Ki-moon challenges climate sceptics:
Speaking at the University of Sydney, he talked of the need for world leaders to address global challenges including climate change, pandemics, and issues involving food, energy and waste.
Regarding climate change, he urged sceptics to visit the Pacific island nation of Kiribati, where rising sea levels are a very real threat.
The impoverished nation was facing a bill of $947 million just to protect infrastructure from the effects of climate change, and had yet to come up with viable ways to relocate some of the population.
Mr Ban added the country was running out of time and hoped Australia would lead the way "for your own good as well as well as that of the planet".
I for one don't need to visit Kiribati to see "rising sea levels" there. Latest data from the South Pacific Sea Level and Climate Monitoring Project run at the BOM (to end of July 2011) which I've just graphed -

Betio, Kiribati – trend from Jan 2002 to July 2011 -5.48 mm/year

An ounce of data is worth a ton of hot air.

Monday, 29 August 2011

Pole Position

They made it! The intrepid 5-man "Old Pulteney Row To The Pole" team managed to drag their boat "Old Pulteney" the final few miles over the ice to the.... To the what? To the North Pole, stupid! Or is where they ended up the north Pole? Since that spot is on an island, and since the North Pole is not, then what was their objective? Aaaah - it was to the magnetic north pole - that's all right then. But wait, on their website, they say
The Magnetic North Pole is continually moving. It was originally reached by James Clark Ross in 1831. At the time it was located on the Boothia Peninsula, Canada.
More recently the Canadian government made attempts to measure it and show its movement northwestward.
This was eventually successfully achieved in 1996 when an expedition certified its location by magnetometer and theodolite. This was the first time it has been accurately measured. The expedition was led by David Hempelman-Adams and included Jock Wishart.
The measurements were accepted by the Canadian government and it became a recognised and certified position at;
The position is 78°35.7N 104°11.9W / 78.595°N 104.1983°W.
So it was at that position in 1996, and as they say, "The Magnetic North Pole is continually moving". so where is it now?
The speed of movement of the Pole began to increase significantly in a northwesterly direction about 1998, and now averages about 37 miles each year and so It is currently projected to be in a position in Siberia by the end of the century. 
Let's get this straight, they weren't rowing to the North Pole, as many newspapers and TV news reports stated. They weren't even rowing to the Magnetic North Pole, they were rowing to where the Magnetic North Pole was in 1996! So where is it now? Google maps knows:

Using the scale at bottom left, and using Mark One eyeball, that position would seem to be about 500km NW of their finishing point, marked by the red arrow. That red arrow is pointing at a spot only 78°N - some 12° south of the North Pole, and a long way away. What does this expedition prove? That the Arctic ice is in a bad way, and will be gone soon, and this proved by an exhausting row to nowhere-in-particular, with days spent marooned on land because of that "vanished" ice, and a final 3-day drag-your-boat over the "vanished ice". Or something

Wednesday, 17 August 2011

Slaying Your Own Argument

In a post entitled "CO2 as a radiation valve contravenes the laws of thermodynamics" our old friend and "Dragon Slayer" Alan Siddons analogises the atmosphere as a "radiation" valve. He imagines such a valve letting in solar radiation, but preventing any escaping to space. Of course, in such a system, the Earth's surface would continue to heat up because there's no exit for the heat generated in the surface. He claims that this disproves the "greenhouse effect" because "back-radiation" from the "valve" (the atmosphere) is somehow magnified and therefore causes a "runaway" heating cascade. But with no path for the heat to escape, such an effect is inevitable anyway, "greenhouse effect" or not. It's nosensical, of course, and proves nothing.

The second part of the post describes a "valve" which actually lets some radiation to escape, so is worth examining. However, in summary this is another example of a poorly labelled diagram, which in this case seems to have confused the author himself;

I urge you to notice that the valve's efficiency doesn't actually matter, either, because physical laws are violated even in a modest case. In some sense, in fact, the crimes get worse. For instance, let's install a 20% valve, so that 80% of the infrared escapes and 20% back-radiates. 

In this case, 0.8 exits while 0.2 is "retained" by the surface. But 0.2 also radiates back to the surface, so it gains 0.4 in total (again, as a minimum: further back-radiation effects must arbitrarily be halted). In other words, even when the oft-mentioned "net flow" favors the outward movement of thermal energy (a modeling effort to satisfy the Second Law), the alleged heating effect still contradicts the First Law because you're getting more energy than you put in. Any furnace manufacturer would eagerly exploit such a loophole in the law if it existed. 

"In this case, 0.8 exits while 0.2 is 'retained' by the surface" - yet the upward red arrow at the top reads 0.8, meaning that the red arrow below it must represent 1 unit in order for the "valve" to have absorbed 0.2 units. Not a good start, since if the surface "retains" 0.2 it can only radiate 0.8 with a corresponding 0.64 exiting the "valve". The 0.8 shown escaping plus the 0.2 "retained " by the surface plus the 0.2 absorbed by the valve add up to 1.2 and not 1. Earlier in his post he said "You can't obtain more energy than you put in", yet he's just done it! Apart from this fundamental error, if the surface retains a net anything the system can never reach equilibrium - it has built-in positive feedback from the word go. He says earlier "for every unit of sunlight going in", so if for every unit going in 0.2 is "retained" the surface will continue to heat up, and thus far in the process the the "valve" has played no part in any "feedback". So the diagram doesn't actually represent what the description says it does. In reality the surface never does actually radiate 1 unit, as implied in the diagram, unless the"valve" is initially set to allow all radiation through, and then activated. All that's needed (once again, as in "A Simpe Solution") is to consider the energy actually lost from the system to get a properly thought-out analogy or "model".

At equilibrium, 1 unit escapes through the valve, which means that the surface is radiating 1/0.8 = 1.25, and the "valve" is absorbing and re-radiating 0.25 downwards. But where does that "extra" energy come from? It comes of course from energy absorbed during the equilibrium process. initially the surface acquires 1 unit, absorbs that energy and heats up until it radiates 1 unit. The "valve" absorbs 0.2 of that, and it heats up until it radiates the same down. The process continues with diminishing increments - the 0.2 is absorbed by the surface, increasing its heat content until it radiates 1.2 units, with 0.96 escaping and a total of 0.24 absorbed by the "valve" and so on. Of course, the process doesn't actually have discrete steps - it's smooth and continuous. The heat content of surface and valve increase until radiation in and out of the system balances and equilibrium is obtained. No physical laws are violated, and "furnace maufacturers" are well aware that it takes time for their products to heat up to operating temperature when turned on.

There's the nub of the matter - the "Slayer's" misunderstanding of the difference between heat flow amd heat content. The surface of the Earth and the atmosphere don't radiate because they are absorbing radiation, they radiate because they contain heat. Radiation from the sun merely tops up the heat content. At night there is no radiation from the sun, yet of course the Earth/atmosphere system cotinues to radiate heat to space, slowly cooling. It's surely a simple concept to grasp, yet it appears to elude some.

Tuesday, 16 August 2011

The truth may be only a click away ....

When you read a blog or forum post, or an article on a website do you click on supporting links provided by the author? I usually do, unless I trust the author or site and the article seems comprehensive. When I do check sources, I sometimes find that the author has misrepresented what the sources say, or has left out something that's "inconvenient" for his argument. Sometimes the linked source doesn't even mention what is claimed or says exactly the opposite. I gave an example in an earlier post Clutching at Straws, or "Scraping the Barrel" where a linked post didn't discuss what was claimed at all.

While re-organising my bookmarks, I came across this post titled intriguingly "Solar Ovens Prove Greenhouse Gas Theory is cooked", from "Dragon Slayer" author John O'Sullivan. The article jumps right in and says:
Colorado State University and Brigham Young University's (BYU) Professor Steven E. Jones of the Department of Physics and Astronomy and his student, Jenni Christensen Currit, have conducted experiments that prove that solar ovens are not just a cheap and reliable way of ‘free energy’ cooking but are also useful tools for disputing theories that the planet is in danger of any runaway catastrophic warming due to fossil fuel emissions. 
BYU's study entitled, ‘Solar Cookers for Developing Countries’ shows that the predicted harmful back radiation effect defined by the greenhouse gas theory (GHG), whereby carbon dioxide in the atmosphere is supposedly responsible for re-radiating heat energy (repeatedly up and down as if under a blanket) doesn’t exist in the real world.
The finding challenges the Intergovernmental Panel on Climate Change and certain world governments who have premised trillion-dollar cap-and-trade tax policies on fears that catastrophic global warming may ensue if levels of atmospheric carbon dioxide continue to rise.

So let's click on that link and see what it says. It's indeed a report, but the abstract says:
The developing world suffers from a variety of problems including lack of food, fuel shortage, environmental abuses, and unemployment. Many non-profit organizations work to alleviate these problems, but often find that a coordination between scientists and developers is difficult yet necessary to make effective improvements. This project is an attempt to bridge the gap between technological development and international development. Dr. Steven Jones of Brigham Young University, has been developing solar oven technology for several years. I joined the project after much progress had been made. My project had two phases. The first phase was spent developing solar oven designs that would be both effective and practical in developing countries where money and materials are hard to obtain. The second phase was an effort to take the technology to non-governmental organizations currently doing work in developing countries in an educational approach that would allow them to have a flexible approach to implementing valuable technology for those with the most urgent need. This paper includes the findings and accomplishments of both phases. The educational materials distributed to the organizations are also included as well as a list of groups who have received this information in hopes that future interest will rise and the materials will be made available to an even wider audience. 
Not exactly what we were led to expect, is it? BYU's "study" is not a study at all, but a project, and the only "radiation" mentioned is from the sun, as one would expect in a project to develop and promote solar cookers. However, don't take my word for it - click on the link and see for yourself. There's no "finding" that disputes anything, let alone the Intergovernmental Panel on Climate Change (IPCC). Linking to and totally misrepresenting a report which has nothing whatsoever to do with your claim is deception, pure and simple.

O'Sullivan's post continues:

Cooling or Warming: Ovens Satisfy Laws of Thermodynamics
Remarkably, the researchers doing a similar experiment at Colorado State University tested solar ovens not just as cookers but also for their potential to cool food and water both day and night. All solar cookers tested proved highly successful at cooling both day and night as long as they were carefully aimed.
Remarkable indeed, as the only "experimenting" the aforementioned BYU pair did was in
developing and modifying the design of the funnel cooker and to work on developing other designs. My contribution was mainly focused on researching heat-resistant plastic and alternatives to plastic, in addition to testing the funnel cooker and making a new type of box cooker.
Incidentally, the link to the "experiment at Colorado State University" pdf doesn't work in the original post; I've corrected it in the quote. Par for the course it seems. Did the "researchers" at CYU "test ovens not just as cookers"? Not exactly - they describe how to build a "solar fridge". Another non-experiment it seems. O'Sullivan goes on to say
It is proof of a cooling effect that appears to contradict the so-called re-radiation properties of carbon dioxide; if CO2 does cause warming it isn't showing up in these tests. This is because if back radiation was actually reaching the Earth, solar ovens would produce heating at night. But clearly they are not. The findings are set to become a hot topic in the ongoing global warming debate. 
Really? So what does the (incorrectly) linked construction project (which is what it actually is) say on this subject?
An object on the ground “sees” the earth below and the sky above. The sky is cool, the earth is (relatively) warm. The object will cool, because it will emit more than it receives—only half of what it “sees” gives significant infrared back. But an object in the “space refrigerator” doesn't “see” anything warm. The solar oven collects radiation from above—but above is the sky , and the sky is cool. So the object in the box gives off as much energy as an object on the ground, but it gets much less back.
Gets much less back - says it all really. A fine piece of work - citing and misrepresenting one article which is totally irrelevant, and another which actually refutes what's claimed as "evidence" . So we have even more "clutching at straws" except that in this case they're not even straws.

Sunday, 14 August 2011

Glossary of Global Warming and Climate Terms

A light-hearted but satirical translation of terms and phrases in scientific papers, internet articles and news reports. Don't take it too seriously but remember that satire is best when a thread of truth (however thin) runs through it. The list is not in alphabetical order because it follows a tenuous narrative. It's not complete - I just jotted things down as they occurred to me. If you have any comments or suggestions, feel free, you know what to do. I had a lot of fun compiling the list; I hope you have some reading it.

Term or phraseTranslation
See Bloggs et al. 2003One day we might read it too
Bloggs et al. 2009We hoped you wouldn't mention that
GlobalBits of the Northern Hemisphere studied
RegionalThe area covered by our map
Ocean acidityOcean alkalinity
Increasing acidityReducing alkalinity
Low pH sea-waterSea-water with hydrochloric acid added
High pH sea-waterSea-water with no hydrochloric acid added
High morbidityLittle buggers don't like hydrochloric acid
W/m²Watts per square metre
WattOne joule per second
WattsThat damn blogger
ProxyTree rings, ice cores or sediments
Tree ringsThe "lonesome pine"
YamalA few "lonesome pines"
The Hockey StickTwo graphs for the price of one
"Nature trick"A surreptitious grafting operation
Statistical techniqueSmooth the hell out of it
Mediaeval Warm PeriodWe got rid of that (see Statistical technique)
Little Ice AgeAn urban myth (see Statistical technique)

Wednesday, 10 August 2011

Clutching at Straws, or "Scraping the Barrel"

I used to like the Hockey Schtick, often first with news of new scientific papers or articles on global warming, until the blog became a mouthpiece for the Dragon Slayers with their distortions and pseudo-science. A recent post there claims that a climate scientist  "inadvertently explains why greenhouse theory is wrong". The post links to a video of Professor David Archer of the University of Chicago giving a lecture to non-science majors on modelling the "greenhouse effect":
In lecture 5, The Greenhouse Effect, Archer uses the Stefan-Boltzmann equation to calculate the supposed temperatures of Venus, Earth, and Mars with and without a greenhouse effect. Archer's calculations show the greenhouse effect on Venus is wildly underestimated by 415C and wildly overestimated on both Earth (by 23C) and on Mars (by 19C) in comparison to actual observed temperatures. This is despite the fact that CO2 levels are very high and virtually the same on Venus and Mars (around 96%) and only trace (0.039%) on Earth. Archer says in the lecture that one would have to assume the Venus atmosphere behaves like multiple panes of glass in order to obtain an answer near the observed temperature, yet on both Earth and Mars one would have to assume the atmospheres behave like much less than one pane of glass. 
What is not said is that in the lecture, Archer develops a very simple atmospheric model, using a "pane of glass" to represent a totally absorbing atmosphere, and at the end shows that its results are wrong for all three planets. So this post is claiming that a very simple "one-layer" atmospheric model, which as Archer explains is being used as a step towards a more accurate "multi-layer" model, and which produces the wrong results somehow disproves the "greenhouse effect"! Give me a break! Incidentally, what's "much less than one pane of glass", which it's implied Archer has said (he does not)? The post continues:
H/T Professor Claes Johnson, who explains why Archer also uses the Stefan-Boltzmann equation incorrectly (and here)
The first link which purportedly "explains why Archer also uses the Stefan-Boltzmann equation incorrectly" doesn't mention Stefan-Boltzmann at all. Misrepresent what was being taught in the lecture, leave out relevant parts, come to an unsupported conclusion. and supply a link which doesn't address what you claim it does.The entire post is really scraping the barrel.

A Simpe Solution

In Zen and the Second Law of Thermodynamics I discussed claims of the non-existence of the so-called "greenhouse effect". Some of those claims use analogies or examples to "prove" the point. Most of these are misconceived at best and erroneous at worst. Most scientists and informed non-scientists accept the basic physics. I won't say "99%" or similar because I'm aware that 87.37% of statistics are made up on the spot, and in any case I don't know what the figure might be. This is not an "appeal to consensus" - the basic physics involved is well understood and founded on fundamental physical laws.

Here's such an analogy designed to "prove" that the infrared radiation ("back radiation") from the atmosphere to the Earth's surface either doesn't exist or cannot have the claimed effect. Not surprisingly, it's from one of the many authors of "Slaying the Sky Dragon" who thinks he's illustrated "perpetual feedback":
Say you have a blackbody plate (think of an electric heater) radiating 1000 W/m² toward another plate which, because of distance, absorbs half of that intensity, i.e., 500 W/m². At equilibrium, the receiving plate thus radiates 250 W/m² toward the 1000 W/m² plate. Question: Does the 1000 W/m² plate thereby rise to 1250 W/m²? If so, then, by raising the radiator's temperature without adding more energy, you've disproved the first law of thermodynamics. Effectively, you've made the radiator heat itself. Moreover, now at 1250 W/m², the radiator will heat the other plate still more, absorb another dose of back-radiated energy, and will reach 1562 W/m². And so on, ad infinitum.

This seems to prove a feedback causing a runaway heating in the system. However, the author (Alan Siddons) is confusing an infinite geometric series (with a finite sum) to a never-ending sequence of feedback. Let's look closer at the diagram. Something is missing (par for the course in these analogies). In this case it's the radiation lost from the system, and examining that will directly give us the equilibrium conditions.

At equilibrium, the two-plate system is receiving the equivalent of 1000 W/m² via the heated plate, so the system must lose that energy to the surroundings. If the heated plate is now radiating x W/m², then x/2 W/m² is being lost to the surroundings. The receiver is absorbing x/2 W/m², so must be radiating the same amount, with half of that radiation, x/4 W/m² lost to the surroundings. We have a simple expression to solve:

x/2 + x/4 = 1000   so 3x/4=1000  and x = 1,333.3

The heater radiates 1,333.3/2 = 666.7 (actualy 666.66 recurring) to the receiver, which radiates half, or 333.3 back:

Balance is restored and no runaway heating. But where does the "extra" radiation come from, which as claimed above "violates the First Law"? It comes from the heat energy stored in the system during the equilibrium process, and the amount depends on the specific heat of heater and receiver. There is no violation of the First Law, and no violation of the Second Law either. Net flow between the two plates is from hotter to cooler, with both plates heating up until overall equilibrium is restored. Al the heat energy in the system came from the heated plate, which has some of that returned to it from the receiver. The returned heat reduces the net heat lost from the heater, so because the input remains the same, it heats up until the heat lost from the system equals the heat input.

Does the cooler receiver "heat" the hotter heated plate? No, it simply replaces some of the energy radiated (and therefore lost) from the heater, so it's the continual 1000 W/m² energy input which does the heating. Mr. Siddons has himself said "a cooler body cannot heat a hotter body, it just slows the rate of cooing". This is a perfect example - initially the heater radiates 500 W/m² to the receiver, reducing to a net 666.7 - 333.3 or 333.3 W/m² at equilibrium, and the result is a hotter radiator, radiating a total of 1333.3 W/m².

The misconception arises from only considering the instantaneous input to the system and ignoring the heat stored during the equilibrium process, a common thread in such discussions. If you intend waving a big stick, make sure you've got hold of the right end of it first.

Tuesday, 2 August 2011

Skating on Thin Ice in Winnetka

I'd never heard of Winnetka, Illinois until yesterday. It seems the worthy residents are reluctant to spend as much as $750,000 for a system to guarantee winter ice at their outdoor skating rinks. Triblocal reports:
a 2008 Winnetka Caucus survey polled members on the subject. It asked if residents would support a $700,000 to $750,000 “removable ice system” at Indian Hill Park. Of the 1,170 people who responded, 73 percent voted against it. 
Sensible folks, but where does the drive for such a project originate?
Global warming presents a potentially dire future for Winnetka, warns a Park District report.
“This would obviously mean the end of outdoor (ice) skating in Winnetka,” the report says.
Citing the threat posed by global warming, the Winnetka Park District is investigating ways to continue providing outdoor ice skating should winters become shorter. And it would only cost the district $450,000 – less if it just rents a global warming-resistant rink, instead of buying its own.
Now we have it - "the threat posed by global warming". Where did notice of this threat originate? The state government? The federal government? The local weather bureau? The IPCC (International Panel on Climate Change) 2007 report? "A regional climate model? No - a report on "global warming" in the Wall Street Journal (I can't find a link).
The report cites a June 16 Wall Street Journal article about global warming that said “Chicago’s weather could someday resemble Hunstville, Ala.”
Indeed it could, but it could also resemble Vostok station, Antarctica, as it once did when Chicago was under about one thousand metres of ice, during the last ice age. An investor who wishes to buy or sell shares will examine the price record for the shares. Let's examine (as the Park Board should have) the winter temperature record for Chicago (14 miles to the south) and similarly situated on the shore of Lake Michigan:

Winter (Dec-Feb) 1991 - 2011 Trend = -2.02 degF / Decade

The average winter temperature (with two exceptions) has been below freezing over the last 20 years, and that looks like a distinct downward trend to me, but then I'm not a WSJ reporter. However, if I was a Winnetka taxpayer, I'd hang on to my money.

Saturday, 30 July 2011

"Mark One Eyeball" - an Effective Weapon Against AGW

About a year ago, I read with some amusement, a blog posting by someone who accused sceptics (of AGW) of "cherry picking" temperature data to prove their claims that climate warming had stopped in the current century. "They are looking at the wrong data" he opined "look at this". "This" was a temperature chart showing global temperature from 1900 to 2010. "It's the long-term trend that's important" he continued. I'll use his tip if my bank account goes into the red in the future. When I get the letter from the bank, I can tell them "You're cherry-picking data - It's the long-term trend that's important".

So what's the "Mark One Eyeball" I refer to in the title?
This term is actual British military slang for eyes or eye sight, derived from British Royal Navy nomenclature for distinguishing sequential variations of a piece of equipment (i.e., "Mark 13 Depth Charge"). Since the human eye has not changed, it is called the Mark I Eyeball. The term is typically used when someone relies too much on their equipment: "Use your Mark One Eyeball!". It is used likewise in the United States military and other predominantly English-speaking countries. 
The point I'm making is that the "Mark One Eyeball" used with our "Mark One Brains" (no better versions available currently) is a valuable tool for spotting trends in graphical data, and to a lesser extent in tabular data. The eye/brain combination seeks to identify shapes and lines in collections of dots, blobs or points on a graph. The MOE is also good at spotting conflicting scientific or statistical claims, sometimes made by the same person. In December 2009 Dr. Vicky Pope, who is head of the climate predictions programme at the Hadley Centre of the UK Met Office, was (apparently) quoted in a BBC report "figures indicate that the years since 2000 - the "noughties" - were on average about 0.18C (0.32F) warmer than years in the 1990s; and that since the 1970s, each decade has seen an increase of about the same scale". MOE was telling anyone who cared to look at ANY temperature dataset that this couldn't possibly be true. This is the Hadley Centre's own data for 1991-2009:

Tuesday, 26 July 2011

An Element of Surprise

I'm surprised at how scientists are often surprised, and sometimes even astonished. For example, researchers and marine biologists were surprised by the rapid recovery of nearshore environments along the US coastline of the Gulf of Mexico in the months following the Deepwater Horizon blowout in 2010. Marine biologists were surprised at the rapid recovery of bleached areas of coral along the Great Barrier Reef off Queensland, Australia. Others had been surprised at the extent of the bleaching in 2008. Scientists were "Surprised to Find Earth's Biosphere Booming" (abstract here) when they looked for the first time, though whether it was the scientists themselves, or merely reporters who were surprised, is a moot point . Scientists were surprised (some were astonished) to find an "ozone hole" (so-called) over Antarctica several decades ago, when they looked for the first time. Scientists at Woods Hole Oceanographic Institution were surprised to discover that some shell-building creatures unexpectedly build more shell when exposed to ocean acidification caused by elevated levels of atmospheric carbon dioxide (CO2).

With all these expressions of surprise (most seem to be confined to press releases or interviews, may be a clue there?), it might be interesting to attempt to analyse the reasons. Had the scientists studied earlier oil spills and ecological impacts? If so why were they surprised at the rapid recovery? (I wasn't, but then I'm not a marine biologist). Large oil spills in colder waters were followed by rapidly reducing impact and fairly quick recovery. In the Gulf the water is much warmer, which should mean more rapid dispersion of the oil, and conditions conducive to oil-gobbling bacterial growth. Sea conditions also favoured skimming and collection of the surface oil close to the US coast, and rougher weather further out dispersed the oil. Perhaps they'd been influenced by all the reports of an ecological disaster which hadn't yet occurred in the first few days and weeks of the spill? Perhaps they just had pre-conceived notions of the likely extent of the damage and slow recovery speed. If so, they go down a notch in my estimation.

Wednesday, 13 July 2011

A Warm(ists) Look at Glaciers

This caught my eye today (h/t Tom Nelson), titled "Canadians ought to care about the radical changes occurring in the polar regions", by Geoff Green, who describes himself as "Arctic Explorer - Environmental Educator".

In response to the question (the piece masquerades as an interview, though the byline is "by Geoff Green") "What inspired you to start bringing youth on Arctic expeditions?" he replies
What inspired it all was really seeing how incredible the polar regions are – how they are these cornerstones of our global ecosystem; windows to the health of the planet. Not to mention the fact that they are just beautiful places, home to huge concentrations of wildlife.
It's hard to pinpoint an exact moment, but I do remember one day standing on this beach in the Arctic surrounded by about 200,000 chinstrap penguins
It must be "hard to pinpoint an exact moment" because pygoscelis antarcticus, as the name rather gives away, are resident in the Antarctic. He continues
And I thought, “Imagine if we could bring kids or youth to these places at the beginning of their lives – at a time when that type of experience could help define their future and change their perspectives and motivate and inspire them.” I thought, “Wouldn't the polar regions be the greatest classroom on earth?”
For kids to be able to look into the eyes of a bowhead whale or a polar bear, and to experience the unbelievable beauty of the Arctic … I knew that would change them on a personal level and connect them, not just to nature, but to their place in this big global picture.
I suggest that if a kid looked into the eyes of a polar bear, he/she would connect directly to nature by becoming part of the food chain. Still, perhaps I'm being unfair, so let's read more
We are also seeing the affect on glaciers that are shrinking. We often go to Auyuittuq National Park. Auyuittuq is an Inuktitut word meaning “the place that never melts.” They’re going to have to change that name. They had to close the park three years ago because of flash flood warnings due to the rapid melting of the glaciers. Greenland is in the same situation.
"due to the rapid melting of the glaciers" - sounds catastrophic, surely glaciers don't melt, do they? What does the Auyuittuq National Park of Canada site have to say?
Auyuittuq National Park Closure is lifted as of August 8, 2008
Due to rain on snow, two weeks of record breaking warm sunny weather followed by more rain Summit Lake filled well beyond normal limits and burst out through the normal drainage into the Weasel River and scoured the outflow channel to bedrock through permafrost sending a pulse of extreme high water through Akshayuk Pass.
Subsequent to the high water that took out the Windy Lake bridge and some trails, areas of permafrost continued to melt causing erosion, cracking and slumping of affected areas from Crater Lake to Summit Lake. 
Nothing there about glacier melt being a major factor. When did those lakes form? The Great Canadian Parks site tells us
Three of the park's lakes, Crater, Summit and Windy, were created about 100 years ago when moraine ridges of gravel and boulders formed a natural dam that held back the meltwater when the glacier retreated. Much of the land is in the permafrost zone, where the earth's moisture, just centimetres below ground, is frozen solid for all time. In summer, the surface can become a slurry of sand and gravel, a hazard to hikers who must also beware the Owl River valley, where thawing is capable in some sections of creating waist-deep quicksand-like quagmires.
So the glacier had a major retreat 100 years ago, and it doesn't appear that there's any plan to change the name from Auyuittuq "the land that never melts" anytime soon. The previous paragraph gives some background
The buckling of bedrock by continental drift forces formed the Precambrian granite peaks of the jagged Penny Highlands which reach 2100 metres and range over 6000 square kilometres of the park’s landscape. The ice cap produced by the compression of accumulated snow into glaciers covers the highlands to depths of 300 metres. The remaining 2/3 of the park is mainly covered in ice that melts only at its edges and then only during the brief summer. The peninsula's coastline is cut deeply where glaciers shaped the valley floors below sea level, chiseling narrow fjords with 900 metre-high vertical walls. Glacial action that gave the valleys, such as the 97-kilometre Akshayuk Pass, their characteristic U-shape, is still actively shaping the land. 25 kilometre-long glaciers, spawned from the massive ice cap, slide down from the high plateau to the sea at Davis Strait pulled by gravity and their own weight. Glacial moraines - huge mounds of eroded rubble pushed by a moving glacier, and sandy areas where rock was ground into particles have become part of the landscape.
They don't sound as though they're concerned about future job prospects.

I recall an article I read several years ago (link long lost), in which a glaciologist (could it have been Geoff Green?) was recounting his depressing experiences on the Antarctic peninsula. He said "I was kept awake all night by the mournful sound of the melting glaciers". Kept awake? By the sound of flowing water? No, "the sound of the ice crashing into the sea". I haven't got a PhD in physics, but I do know when ice melts it becomes water, and it doesn't "crash into the sea". I'd suggest that scientists who are too emotionally involved with their subject of study might tend to be somewhat less than objective in their conclusions.

A Cool Look at Glaciers

Glaciers are the poster child of those who would have us believe that unstoppable global warming is in progress. We've been told that melting is accelerating just about everywhere, and that hundreds of millions will be affected in the future if glaciers continue to melt and reduce the boost they give to river flow in the dry season in areas like south-east Asia.

Glaciers hit the headlines in a big way in December 2009, when reports of a flawed prediction about Himalayan glaciers began to circulate on the internet. They quoted a statement in the IPCC 2007 AR4 report:
Glaciers in the Himalaya are receding faster than in any other part of the world (see Table 10.9) and, if the present rate continues, the likelihood of them disappearing by the year 2035 and perhaps sooner is very high if the Earth keeps warming at the current rate. Its total area will likely shrink from the present 500,000 to 100,000 km2 by the year 2035 
IPCC AR4 WG2 Ch10, p. 493

Monday, 11 July 2011

The Battle of the Bulge

National Geographic News tells us:

Earth Has "Spare Tire"—And Ice Melt's Keeping It That Way 
Waistline bulge has stopped slimming, thanks to massive melting.
Earth isn't losing its "spare tire" as fast as it should be, according to new research—and it's definitely not because the planet's not getting enough water.
In fact, melting ice from Antarctica and Greenland (map) is giving the oceans huge infusions of water, which then gets pulled toward the Equator—counteracting a millennia-old slimming trend around the planet's middle, experts say. 
Overall, the current ice loss is causing Earth's bulge to grow at a rate of seven millimeters a decade, Wahr and Nerem found—exactly enough to counteract the long-term rebound, at least temporarily.

This must mean that sea-level rise in the equatorial regions is higher than elsewhere, so let's look at a few places. The largest open body of water is the Pacific ocean, and Hawaii isn't that far from the equator (21°N)

Sunday, 10 July 2011

"Slaying the Sky Dragon" - a critique

I had intended to review the book "Slaying the Sky Dragon" (by a number of authors), but I've decided not to buy a copy. Three of its chapters are now available on the 'net in pdf format. I've read the two chapters authored by Claes Johnson, and I have to say that I'm staggered by their assertions. It doesn't take a climate physicist to see the erroneous assumptions that the flawed arguments are based on.

The chapter "Climate Thermodynamics - 4 Lapse Rate and Global Warming/Cooling" starts off badly:
The effective blackbody temperature of the Earth with atmosphere is -18C, which can be allocated to a TOA at an altitude of 5 km at a lapse rate of 6.5C/km connecting TOA to an Earth surface at 15C with a total warming of 5 × 6.5 = 33C. The lapse rate determines the surface temperature since the TOA temperature is determined to balance a basically constant insolation. What is then the main factor determining the lapse rate? Is it radiation or thermodynamics, or both?
Mr Johnson may be a mathematician, but he's not a climatologist nor a physicist. I'm none of those, but I can spot the equivalent of a "schoolboy howler" when I see one. Let's analyse the first sentence; TOA (Top of Atmosphere) is considered to be around 23 km altitude. The "-18C" has to have been calculated using the Stefan-Boltzmann equation, using the average radiation-to-space value of 240 W/m² (watts per sq. metre). This does indeed give a result of -18°C, and the average temperature at a height of 5 km is indeed -18°C, but there's a snag. The radiation to space comes from more than one source, and its profile is not a complete Planck curve, as required if the Stefan-Boltzmann equation is to be used.

Tuesday, 28 June 2011

Zen and the Second Law of Thermodynamics

The Clausius expression of the Second Law of Thermodynamics:

No process is possible whose sole result is the transfer of heat from a body of lower temperature to a body of higher temperature.

This is unequivocal, so how does the "Greenhouse Effect" in the atmosphere raise the temperature of the Earth's surface? The atmosphere is cooler than the surface, so the flow of heat must be from the surface to the atmosphere, and so it is. Yet a number of people claim that this is proof that the "Greenhouse Effect" does not exist; "A cooler body cannot heat a warmer body" they proclaim, while in fact no-one has even suggested that this is the case. Some even go so far as to claim the so-called "back radiation" from the atmosphere to the surface doesn't exist.

Such claims have no basis whatsoever. Atmospheric longwave infrared "back radiation" has been measured, and its spectrum plotted, routinely since the 1950s. A simple web search can reveal summaries of some of the hundreds of scientific papers on the topic. It is part of the fabric of atmospheric physics. To ignore or dispute the existence of the phenomenon can only be termed denialism. However, disputing the effect(s) of this radiation in detail is another matter entirely. Such arguments can be examined for scientific logic and therefore veracity.

Saturday, 25 June 2011

A Question of Scale (3) - Latent Heat

Latent (hidden) heat plays an important role in climate and weather, but its importance is often overlooked or misunderstood. Heat is simply the energy of vibration of atoms or molecules in solids, liquids and gases. Heat is motion; motion is heat. More motion equals more heat - hotter. Less motion equals less heat - colder.

In a solid such as ice, water molecules are fixed relative to one another. They can move a small amount relative to their neighbours, but can't move freely through the solid; it's as if they were inter-connected by springs or stiff elastic. These notional "springs" are the strong attractive force which operates at the relatively short distance between the molecules.

In a liquid, molecules vibrate much more, and are free to move about, like table-tennis balls in a bucket. Shake the bucket, and the balls move about. Shake it more; balls from the bottom can move to the top, and vice-versa. They collide with one another, thus transferring energy of motion (kinetic energy). More vigorous shaking may result in a ball leaping above the others - it may even leap out of the bucket. This is a simple illustration of evaporation - balls moving through the air have effectively become a gas.

In a gas, the molecules have much greater energy of motion, and are free to move in all directions like the balls that escaped from the bucket. They collide one with another, transferring and sharing their kinetic energy. As a consequence they are much farther apart than molecules in a liquid or solid.

To transform a solid into a liquid, enough heat has to be added for the kinetic energy of the atoms or molecules to overcome the strong attraction between them. The amount of heat per unit of mass of the solid is termed the latent heat of fusion for that solid. It is many times greater than the specific heat, which is the amount of heat per unit of mass to raise its temperature by one degree Celsius (or Kelvin). Why is this important? It takes far more heat to melt ice than it does to warm ice to its melting point.

The specific heat of ice is 2.108 kJ/kgK (thousand joules per kilogram per degree Kelvin); the latent heat of fusion of ice is 334 kJ/kg. It takes 158 times as much heat to melt a given mass of ice as to raise its temperature by one degree. It appears to me that it's a common misconception that once ice is raised to its melting point it will melt rapidly. It would take 158 times longer to melt ice than to raise its temperature the last degree to the melting point, given the same rate of heat input.

We use this property of ice almost daily. A couple of ice cubes in a glass of juice or spirit lowers the temperature rapidly, but that cooling reduces the heat available for the ice to melt, which must then come from the surroundings - the sun, the air or a warm hand. A large ice-floe or iceberg can drift for months before disappearing completely. Some of the much larger ones can endure for years. The ice that does melt removes a lot of heat from the surrounding air and water, reducing the temperature difference and slowing the transfer of heat and therefore the melting rate.

Enough about ice - I can see the bottom of my glass. Conversion of a liquid into a gas, as in water to water vapour (or steam) requires an even greater input of heat energy as does melting. The figure of 334 kJ/kg for ice to water compares with 2,270 kJ/kg for water to vapour - nearly 7 times as much. This is important because it's the mechanism by which vast quantities of heat energy are transported aloft from the surface of the Earth into the atmosphere. It's a major factor in climate - some would argue (including myself) that it's the major factor.

Evaporation of water cools land and more importantly ocean surfaces, the resulting upward convection drives surface winds, and the water vapour condenses to forms clouds which block sunlight from reaching the surface. The condensation into clouds releases the latent heat into the upper atmosphere, where it's better placed to finally radiate into space and balance the incoming dynamo of the climate; energy from the sun. Water and its latent heat therefore has a major impact in cooling the Earth's surface, a direct result of its unusual properties compared with other common substances.

See this page for the properties of dihydrogen monoxide (or hydroxyl acid - it's nasty stuff, thousands of people die because of it, or a lack of it, or in it, every year).

Thursday, 23 June 2011

A Question of Scale (2)

The atmosphere is, as I have previously said, very large. It extends tens of kilometres above the Earth's surface, though because of rapidly decreasing density, half the total mass is contained in the first 5 km. Ocean volume is less, almost exactly half of the "normalised" (1 atmosphere pressure) atmosphere. A good illustration can be seen here, which shows the relative size of the Earth and spheres representing ocean and atmosphere.

However, while the atmosphere has a larger volume, it has a much smaller mass; the atmosphere is a mixture of gases, and the ocean is liquid water with small amounts of dissolved solids. Normal atmospheric pressure at the Earth's surface can balance a column of mercury (which is a very dense liquid metal) 760 mm high (just over 3/4 metre); this equates to a column of water 10.33 metres high. Another way to envisage this is to consider that the atmosphere exerts a pressure equal to the weight of the column of air above a given area. The pressure is 1.03325 kilograms per square centimetre; the height of a column of water weighing 1.033 kg, and therefore exerting the same pressure on 1 is 1033 cm or 10.33 metres. The mass of the atmosphere is equivalent to a depth of just 10.33 metres of sea water. When the ocean area is taken into account (71% of the earth's surface), this equates to 14.5 metres depth of ocean.

When heat content or capacity is considered, the disparity is even larger. The specific heat (amount of heat needed to heat one gram of a substance one degree Celsius) of sea water is 3.93, the specific heat of dry air is 1.006.

So what does all this mean? It means that the heat capacity of the atmosphere is equivalent to just 14.5 x 1.006/3.93 or just 3.7 metres of ocean depth. The ocean's heat capacity is hundreds of times greater than that of the atmosphere. When he was explaining about the logic of lighter electrons orbiting the relatively massive atomic nucleus (rather than the opposite as had been claimed by some), Ernest Rutherford said “When you’ve got an elephant and a flea, you assume it’s the flea that jumps.”

When considering the internal driving factors in Earth's climate, the atmosphere is the flea, and the ocean the elephant.

Tuesday, 21 June 2011

A Question of Scale

In considering physical systems I find it essential to have a concept of the relative size of things and quantities. For example, the carbon dioxide (CO2) concentration I referred to in my last (and first) post is usually quoted in parts per million (ppm) - actually measured by volume, so more accurately ppmv. Strictly, ppm refers to concentration by weight. The currently accepted concentration is 390 ppmv, which sounds a lot, until it's expressed as a percentage; 0.039% or just under four-hundredths of one percent. As a fraction it's 1/2564.

However, the atmosphere is very large, and that 0.039% represents about 2,500 gigatonnes (billion tonnes) of CO2. That seems pretty big, until it's compared with CO2 dissolved in the world's oceans - about 50 times as much, carbon in the biosphere (all living things, including bacteria and plants) - several hundred times as much, and in carbonate rocks in the earth's crust - several thousand times as much. For comparison, the amount of CO2 emitted annually as a result of mankind's activities is estimated to be about 32 gigatonnes.

So is that 0.039% important, or at all significant? Of course it is - the question though, is how significant. Despite contrary assertions, there is strong disagreement about the relative importance of that (increasing) amount on Earth's climate and ecology. Someone once said "There's what we know about the climate, there's what we don't know about the climate, and there's what we don't know we don't know about the climate. Of these three, the last is by far the largest". I would suggest that applies to every area of scientific theory and research, though perhaps in different proportions.

Saturday, 11 June 2011

A Personal Viewpoint

Sometime in 2003, I developed an interest in the subject of Global Warming. Newspaper articles discussed the perils of a warming world, the forthcoming global food crisis, and the touted culprit was carbon, or to be more precise carbon dioxide, which is much different. I was supposed to be concerned about my "carbon footprint", be doing more to use "sustainable" foods, fuels and products, and to be seen to be doing "my bit" to "save the planet".

Always having subscribed to the motto "take no-one's word for it", I decided to do a little research on the internet. I was surprised to find myself in an enclosed sphere of blogs and websites, many of which seemed to me to have a rather shrill background tone, and much of the analysis seemed to be unquestioning and authoritative. There was very little on the actual science of this "Global Warming", such as references to research papers or articles written by actual scientists. Blog discussions were almost entirely between comment posters who clearly knew one another, and were generally in agreement. I read that the "science was settled", and that phrase alone alerted me that there was a little too much certainty in these discussions.

One item on one website was the clincher - an article on "acid rain". This had been a great scare many years ago, but the subject had disappeared from news reports once it became clear that many of the scientific studies were badly flawed. Trees were not dying at an unprecedented rate worldwide, much of the observed "damage" had been occurring for decades if not centuries, and the acid that was detected in the soil around the trees was mostly created naturally. The article was unquestioning; acid rain was a serious problem, it was entirely due to the burning of coal in power stations and from some industrial processes, and the forests were doomed to all but disappear within decades. The fact that decades had already elapsed since the "problem" was identified, and no arboreal disaster had occurred was clearly being ignored.

The author had penned several other articles, which now received my critical attention. One of these claimed that carbon dioxide (CO2) had increased since the start of the industrial revolution, and now stood at over 3% of the atmosphere, due to the burning of coal and other fossil fuels. I knew that CO2 was considered to be a "trace gas" and so couldn't possibly occupy 3% of the atmosphere, so dug around a little to discover that the correct figure was just over 0.03%, which is 100 times lower. En route I also found that water vapour was the main "greenhouse gas" and was in fact more powerful, molecule-for-molecule, than CO2. I commented on the article, pointing out the error, and was rebuffed - "How could a gas at only 0.03% of the atmosphere have much effect? The correct figure is the quoted 3%". However, I had by then discovered an authoritative report, which had been published by a body called the IPCC, which confirmed my figure, so I returned to the article to find that I'd been labelled as a "skeptic". Undaunted, I provided details of my source, with several other references and posted another comment, which I later found had been deleted. Seemingly, facts were inconvenient for the author and his supporters. I had learned a valuable lesson. I had also noted his response - how could a gas at only 0.03% of the atmosphere have much effect?