January 10, 2017 | Graham

So how fast is the sea really rising?

Some more on the BOM Annual Climate Report, or at least the reaction to it. Speaking on the World Today, Professor Will Steffen said this:

In terms of our coastal zones we’ve got to take seriously the issue that sea levels are rising and storm surges are coming in on a higher sea level.

The sort of thing we saw on an east coast low around the Sydney city area, they’ll become more common, so we’ll have to change our zoning planning and strengthen our infrastructure along the coast.

So, exactly how much are sea levels rising. Again, graphs tell the story pretty well. And the answer is, not much on the east coast, but a bit on the west. As water is more or less level wherever you are, the reason that WA is falling is that the coast is actually being tilted down as the continent runs up against the Asian land mass at the north.

This may also have something to do with the fact that there is not much evidence of sea level rise on the east coast.

But irrespective of the cause, the figures tell the story. If sea rise is either not happening, or only very slowly, then you can’t take Professor Steffen’s comments too seriously.

From comments on my previous post I expect someone will object that there is only a small number of geographical locations represented here. That doesn’t matter. The points have been chosen because they are close to large population areas, and so they are the sea level rises that most Australians experience. And as “water finds it own level” these should be very representative of what happens around a very wide area.

The equations on the graphs give you a tool for determining sea level rise on an annual, decadal or centennial basis, or any other basis you care to name. The Y axis is in metres, so 0.001 is a millimetre worth of rise in a month in the x coefficient in the equation. There is really not a lot to see here, and what you can see here is giving us lots of warning to move.








Posted by Graham at 8:00 am | Comments (3) |
Filed under: Uncategorized

January 07, 2017 | Graham

Global warming hysteria needs to take a longer view

Climate change is accelerating, according to the latest annual climate report from the Bureau of Meteorology, with 2016 tipped to have been the hottest year ever recorded globally.

according to The Australian. And because it is the BOM, no one bothers to check.

In fact, when you go to some of Australia’s oldest and best maintained climate records there is precious little sign that there is any significant warming happening, and none that it is accelerating.

These graphs, taken from BOM data for a number of Australian lighthouses tell the story.

I’ve chosen these data sets for a number of reasons.

  1. They are continuous records and have been taken from the same spot over the whole of the time of their existence. So there is no need to adjust them in any way to take account of station shifts, or the urban heat island effect.
  2. The oceans are the drivers of climate and temperature. Taking temperatures close to the coast means you are capturing a more representative sample of what is happening on earth. Inland temperatures can be effected more by things like prevailing winds, and drought or flood.
  3. Lighthouse keepers are pretty reliable folk, or they wouldn’t be doing what they do, and as a result I think we can assume that they are probably pretty reliable when it comes to taking temperature. Probably more reliable than say postmasters, who have a lot of other things on their plate.
  4. These cover the east, south and west parts of the continent. So it is relatively comprehensive. I think given a choice between lots of bad, short term data, and relatively few, but incredibly high-quality data, you should always choose the latter. If you’re wondering why nothing from north Australia I couldn’t find anything to match my lighthouse and longevity criteria there, but as global warming is predicted to be stronger away from the equator, that is an issue of lesser importance.

gabo_island_lighthouse_17_01_07 cape_otway_lighthouse_17_01_07

Posted by Graham at 2:18 pm | Comments (14) |
Filed under: Uncategorized