Monday, 11 February 2013

Lies, Damned Lies, and Wiggly Lines

Visitors to this blog may wonder what my underlying motives and views are. I have only one motive; telling the truth. My views vary with time - anyone whose views on any subject don't vary, even a little with time, have a fixed mindset, which is not a good thing. My views change as I learn, and they change as I get a better viewpoint on the "bigger picture" . Anyone who tells you, or leads you to believe, that they know "pretty much all there is to know" on any subject whatever apart from the size of Algore's bank balance, is either a liar or an egotist, or both.

I chose to study the aspects of sea-level change some years ago. One reason was that I perceived that very few people, whether bloggers, their respondents, columnists or news reporters (whatever their title), know anything much at all on the subject. Many think it's pretty straightforward; just measuring the height of the sea at any one point, and plotting a few graphs and trends. How little they know.

Another reason was that I thought that even with a little knowledge, I might be able to shed a little light in an area of low understanding - which shows what little I knew. Sea level varies all around the globe; it varies from day to day, month to month, year to year, decadally and on longer time scales, and it varies from place to place. It varies for a variety of reasons; a change in the mass of water in the oceans, a change in the volume of that mass, with ocean basin volume due to tectonic movements, with temperature, wind strength, wind direction, barometric pressure and ocean currents, and even local gravity. If you think that changes in weather and climate are complex, but changes in sea level are not, think again.

Hurricane Sandy was a child of the ocean, and not of the atmosphere. Some climate scientists and climate modellers appear (and there's plenty of evidence to support my view) to think that the atmosphere controls the climate, and the climate modifies the oceans. How wrong they all are.

A seemingly trivial yet important fact is that the tides generated by the Moon, modified by the Sun, shift more water from place to place over a single tidal cycle of just over 12 hours than all the ocean currents combined do in a year. That tidal  shifting is an oscillation of course, but because the globe isn't covered completely in water, the continents and large islands "get in the way", and the tides modify currents at continental margins quite significantly, creating "eddies" which disrupt, spread, and even temporarily reverse the flow.

The oceans cover about 2/3 of the Earth's surface which gets most sunlight. The oceans also absorb more of the Sun's energy than does the land, and they absorb it to a far greater depth. The land surface warms and conducts to just a few centimetres depth during the daytime. The oceans absorbs visible light and short-wave infrared (about 50% of incident solar radiation, a fact known to few it seems), to a depth of tens of metres. The oceans have a heat capacity thousands of times that of the atmosphere. Physicist Lord Rutherford is reported to have said, in an argument about whether electrons orbited the relatively massive atomic nucleus, or vice versa, "When you've got a flea on an elephant, it's the flea that jumps". The oceans are the elephant, and the atmosphere is the flea.

Studying all aspects of the physics of the oceans is the key to understanding weather and climate. To ignore, marginalise or trivialise the role of the oceans is indeed to "ignore the elephant in the room". The oceans drive and control all the climate oscillations from ENSO to the AMO. Note that climate scientists and modellers study "atmospheric sciences". Draw your own conclusions from that - I already have.

Where is all this leading? Why my post title? I could show you 20 charts for tide gauges which show alarmingly high rates of sea-level rise, to prove something catastrophic is just over the horizon (apt metaphor?). I do not. I could show you 20 charts which show virtually no change for half-a-century, "nothing much is happening", yet I do not. I could show you 20 charts which show a fairly steady decrease over a century, to prove that "sea-level is not rising", and I do not. None of these collections would illustrate the truth, though many people would have you believe that their little collection does. Ignore them - their little collection of wiggly lines and "revealing" trends are only a "cherry-picked" and biased version of the truth; there's a very thin line between bias and lies.

Those of whatever persuasion who cherry-pick are guilty of misrepresentation at best, lying at worst. Those who cherry-pick should remember that their "evidence" may reveal more about them than their "hypothesis" does about the true situation. That their evidence may contain at least one "hidden message" which is visible to anyone who has a truly sceptical eye and a little knowledge, and which may be used to disprove their claims. Those who cherry-pick should remember that they may choke on the stones.

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