Building Models

Ricky Gervais didn’t mince words at the Golden Globes:

Delingpole: Ricky Gervais Deserves a Medal for Roasting the Wankerati at the Golden Globes

At the same event, Jennifer Aniston read out a message from Russell Crowe:

“Make no mistake, the tragedy unfolding in Australia is climate change-based,” he wrote about his home country. “We need to act based on science, move our global workforce to renewable energy and respect our planet for the unique and amazing place it is. That way we all have a future. Thank you. “

How much does Russell Crowe know about climate science? I’ve no idea. Maybe he knows a lot more than I do.

But I’ve been trying to find out more about it. So for the past two years I’ve been building my own climate simulation model, slowly adding new elements to it, to try to make it more realistic.

My latest model has a polyhedral Earth with 80 triangular faces, and I’ve drawn up an outline map of its continents, in approximately the right places, using 24 of the triangles. I’ve also got a Keplerian model of the Earth’s elliptical orbit around the Sun, which I use to find the intensity of sunlight throughout the year on each of the triangles. The air temperature above these triangles is pretty much completely defined by the albedo of the surface – how much of this sunshine is absorbed at the surface, and how much is reflected back into space. So I can calculate air temperatures throughout the year.

I then simulate the start of an ice age by dropping water on all 80 triangles. If the air temperature is above 0º C, it falls as rain. If below 0º C, it falls as snow. I assume that snow melts when it lands on the oceans. Using a continental albedo of 0.2 the snow only settles at high latitudes, as shown on the map below of all 80 triangular faces:

With a slightly more reflective albedo of 0.3 (granite rock), the snow settles further south:

The numbers on the triangles give snow depth in metres. If albedo is raised to 0.4 (desert sand), the snow settles as far south as 30º N:

Once the snow starts settling it gradually gets deeper. And the surface rocks beneath the insulating snow gradually warm up, and begin to melt the overlying snow. And so even though it continues to snow, the snow sheets gradually thin and melt. In this model the snow only gets to be about 600 – 700 metres deep at high latitudes near the poles. But it all gradually melts away as the underlying surface rock heats up. It melts slowly at high latitudes, quickly at low latitudes. After it has all melted, there’s a short pause (an interglacial period) while the surface rocks cool down again, after which the snow starts to settle and build up again.

It’s a very simple numerical model. And it runs on my home computer. And it has all sorts of missing elements (e.g. air movement, ocean currents, to name just two). But it’s already proving instructive.

For example, most maps of global glaciation during the last ice age show the snow confined to high latitudes above 50º N. But I’m seeing snow settling much further south. Might the discrepancy be because, while ice sheets several kilometres thick will leave moraines and drumlins as evidence of their past presence, snow sheets a few hundred metres deep probably will not leave much evidence? Perhaps, as my model improves, the snow will become confined to high latitudes. But right now I’m inclined to think it may have got much further south. And I have good reason to believe so: my own calculations show it.

And I can’t see any other way to form an opinion about the Earth’s climate, except by building my own model. It’s like making a paper plane to see if it will fly: how else do you find out? If you haven’t got your own model, you’ll simply be relying on someone else’s. How do you know if they’ve got it right?

Maybe Russell Crowe has got his own much better climate simulation model running on a supercomputer, and when he’s not making movies he spends his time tinkering with it, adding mountains and tectonic plates and volcanoes? Maybe Jennifer Aniston has got an even better one than his?

But I suspect that neither of them has any model at all, and they are just repeating what they’ve been told to say. But isn’t that what actors are supposed to do: read from a script?

About Frank Davis

This entry was posted in Uncategorized and tagged , , . Bookmark the permalink.

9 Responses to Building Models

  1. rms says:

    Well done. I get the logic and I’m quite sure you are on to something.

  2. RdM says:

    Although I haven’t read the comments there yet, perhaps you might consider posting a summary in one (or several) in this link.
    Might get some useful attention and commentary, interest?

    • Frank Davis says:

      I’m interested in the article, but not in leaving any comments. Maybe when I’ve got some results that I’m confident about, I might do something like that. But for now it remains a work in progress about which I periodically post something here, if it seems interesting enough,

  3. Rose says:

    “Make no mistake, the tragedy unfolding in Australia is climate change-based,” he wrote about his home country. “We need to act based on science, move our global workforce to renewable energy and respect our planet for the unique and amazing place it is. That way we all have a future. Thank you. “

    I read another comment on the subject today, published in the Telegraph.

    Letters: Inept forest management laid the ground for the fires in Australia

    SIR – The root cause of the bush fires in Australia is its government’s abysmal record on forest management.

    In 1999 this was taken over by the state authorities, which made any private involvement in preventing the spread of fire virtually impossible. They did not prioritise personal safety or the protection of property, or carry out the traditional spring burning to create the necessary fire-control lines.

    Those who feared for trees or birds were allowed to impede the burning programmes. Last spring, although it was clear that an exceptional effort would be required, the outcome was poor. Weather conditions meant that the burning season was short and protestors further hampered efforts.”

    So I looked to see what precautions were taken in Australia against inflammable eucalyptus scrub and other debris before 1999 and found this –

    Is Fuel Reduction Burning the Answer?
    Current Issues Brief Index 2002-03
    It describes scrub clearing from earliest times.

    Thanks to the commenters on the Telegraph it appears that these days, if you do try to create a firebreak you can be heavily fined.

    In Australia if you try to clear a firebreak on your land you could go to gaol

  4. smokingscot says:

    Ricky did good.

    Crow didn’t quite get it. Same as Robert Redford a few years back.

    Truth is far more mundane. Just a bunch of losers starting fires for the hell of it.

    • Joe L. says:

      I wonder how many of the 180+ arsonists arrested thus far have ties to “green” organizations. After all of the pseudoscience and propaganda that has flooded the world to instill fear of the supposed health risks of tobacco, I wouldn’t be surprised if some (or many) of the Australian fires were started by eco-terrorists in order to further their agenda of climate alarmism.

  5. Joe L. says:

    Ricky Gervais earned a lot of points in my book a few months ago when I found out that he is a very vocal proponent of free speech in an era where it seems that even comedians dare not upset the apple cart of political correctness. After his performance at the Golden Globes, I like the man even more. If only he was a smoker.

  6. Mick Walker says:

    How many of the “arsonists” are actually just practical people creating controlled firebreaks?

  7. Pingback: The Perfect Certainty Of Complete Ignorance | Frank Davis

No need to log in

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.