Nova and Lord – Plumb and Plumber

In another befuddled post, Nova looks (I’m not sure this is the right word for what she does) at Sea Levels.

Nova’s science goes from bad to “oh shit I can’t believe she’s really that stupid!!”. Let’s take a quick look.

Nova’s post on sea level rise has a number of problems.

Exaggeration

Nova says:

Doug Lord examined 120 years of tidal data from Sydney Harbour, and found a 1 mm year on year rise which didn’t fit with the 900 mm rise projected by the Wizards of Climate Change at the Department. He finds the official figures exaggerate ten fold.

1mm vs 900mm – Shouldn’t that be a 900-fold exaggeration?

Oh, but when we look a bit more closely we see Nova’s listed the wrong figure, perhaps on purpose in order to exaggerate the numerical difference, perhaps just by accident because she is not careful when it comes to “the details”.

The 900mm is a projected sea level for the year 2100 (we have to assume, Nova never really explains it), the sea level rise expected for 90 years, starting slowly and then accelerating as the temperature change also accelerates as as land ice melt also accelerates.

Comparing a 90 year projection against a one year change is dumb enough to begin with, but that’s not the dumbest part…

The Past is not the Future

Seems like a simple enough concept. The climate has always changed, why would Nova expect the next 100 years to be exactly like the past 100 years?

That’s exactly what she and Doug Lord do. They look at what happened for the past 100+ years, calculate a linear rate over that period, then simply assume that rate will continue as is despite rising temperature and increasing land-based ice melt.

The temperature change for the past 100 years is not the same amount expected from a business-as-usual scenario. Greater ocean temperature results in greater thermal expansion which results in higher sea levels.

The amount of land-based ice melting is already accelerating and that acceleration is expected to continue. The rate is not expected to remain constant; the volume of ice turning into water and adding to the ocean height will not remain constant. Why then would anyone think that the rate of sea level rise would remain stable?

The  IPCC projections are not based upon extrapolating old a linear figure, they expect the rate of rise to increase over time.

Australia vs The World

Then there’s the little problem of the researchers using Australia only data.

Nova science compares Australia-only historical data against a Global projection that accounts for accelerated warming and melting.

It’s little wonder “Nova science” is rejected by all except the swallowers and denialists. I am also heartened to see how quickly readers picked up on their obvious mistakes.

Nova Bias

One funny thing I also notice about the so called “skeptic” Nova. She shows a map of Australia and suggests that “The west coast water is either rising faster or the land is sinking faster…. but on the East Coast, things are slow.”.

Surely it would occur to a proper skeptic, that if you were to question whether a change the height of the land affects sea level measurements, you would accept that it could operate in both direction. A rise in land height would mean sea level rise is underestimated.

Not so in one-eyed Nova-land!!

The Real Picture

Global Sea Levels are rising. Even in the current picture you can see by eye that the change is accelerating. The IPCC estimate for 2100 is based upon that acceleration continuing into the next century. This is based upon physics and evidence showing that the planet is warming and that Greenhouse Gases are a major cause.

(Source)

The IPCC is NOT Perfect

Like all science there always stands the chance (and hope) that new information and data will be presented to improve our understanding.

For sea level rise there is good reason to believe the IPCC underestimated the projection. More recent science suggests that we could be in for even higher levels.

Projections are not linear

Fig. 6. Projection of sea-level rise from 1990 to 2100, based on IPCC temperature projections for three different emission scenarios (labeled on right, see Projections of Future Sea Level for explanation of uncertainty ranges). The sea-level range projected in the IPCC AR4 (2) for these scenarios is shown for comparison in the bars on the bottom right. Also shown is the observations-based annual global sea-level data (18) (red) including artificial reservoir correction (22) (Source)

Nova and Lord’s method of comparing past sea level rise against the expected sea level rise is simply stupid, and this is putting it mildly.

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3 Responses to “Nova and Lord – Plumb and Plumber”

  1. Ig Says:

    To be fair, I think she multiplied the 1mm yearly rise by 120 years and taken the 900mm rise to be also the total rise over the period, rightly or wrongly. So the difference should have been about 8 fold. I agree with the rest of the post, though. Even as a non-science person (sometimes non-sense as well), I can understand that the rise will accelerate.
    Good on you for exposing denialist crap. You, Tamino, SkS, the people at Deltoid etc. all do a good job.

  2. Nick Says:

    I’m worried that you won’t be able to keep up with the endless stream of madness that she generates…she certainly can’t. Good luck.

  3. Nice One Says:

    Nova is a “fire and forget” kind of gal, not really concerned about accuracy.

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