Friday, August 20, 2010
Weather isn't climate, and computer models aren't reality
Earlier this week I posted about the Met Office's shiny new computer that takes as much power to run as a small town, and which predicted the non-existent volcanic ash clouds that grounded Europe's planes and caused untold delay and misery earlier this year.
The problem is that computers are only as good as the information that's fed into them. The first law of computers is GIGO:
Garbage In = Garbage Out.
I learned this when working for the bank over 40 years ago.
Nothing has changed. That law is eternal.
These days little direct observational science is carried out. Data is merely fed into computers and sophisticated programming is used to predict outcomes.
In Formula One computers are used to predict the efficiency of bodywork components before they are manufactured. They are able to do this successfully because they have data going back over many years. This data was obtained by observing actual components in wind tunnels over a long period of time (relatively speaking). Human hands, eyes and brains were there from the beginning to observe and record and work out the scientific principles involved.
That is good science.
Likewise, ship builders use computer programmes to design ship hulls. They obtained the data to build the computer programme from direct observation and measurement of the behaviour of actual model hulls in a water filled tank. This is also good science.
So far so good. In both the cases the principle of GIGO was taken into account. The data was obtained by direct observation, measured by trusted and trained individuals,and a computer programme was written that simulated the effects of those observations. At all times accuracy was uppermost. The data had to be 100% trustworthy.
Now we come to environmental science, notably weather forecasting and climate predicting.
In the case of the non-existent ash clouds, NO DIRECT OBSERVATIONS WERE MADE.
The aircraft that could have flown into and around the clouds to measure the extent of the problem was grounded, under repair.
The only data they had was guesswork.
Remember the first law of computers?
That's right- Garbage In = Garbage Out.
When will these people learn that computers are only as good as the data that's fed into them?
Now I come to my second and more important gripe- Global Warming or Climate Change.
Firstly- I do not dispute that Climate Change is occurring. It's always occuring. It always has and it always will.
Historians and archaeologists show us that Britain was much warmer a couple of thousand years ago. Sea levels were much higher then. Go back a few thousand years and Britain was joined to Europe. The North Sea was a large land mass that archaeologists have dubbed Doggerland. Fisherman often dredge up stone age artifacts from the sea bed. Climate changes and sea levels change.
The worrying new development is a whole new brand of "science" has emerged that claims to be able to predict the future based on the past and using only computer models. This is an alarming trend that cannot be allowed to happen unquestioned.
We all know what happens when computers are allowed to predict the future without accurate data. They get it wrong. 100% of the time.
Over at Wattsupwiththat, Anthony reports on the latest climate model that NCAR has rolled out. You can read about it here:
The Press Release says this:
"The CESM is one of about a dozen climate models worldwide that can be used to simulate the many components of Earth’s climate system, including the oceans, atmosphere, sea ice, and land cover. The CESM and its predecessors are unique among these models in that they were developed by a broad community of scientists. The model is freely available to researchers worldwide."
First and foremost it must be stressed that this is a computer model. And the results are but a simulation of what may happen. Using the first principles of computing, namely GIGO, we have to be convinced that the data being used is 100% accurate, uncorrupted, unmanipulated and trustworthy.
Following the "Climategate" scandal of 2009, when scientists at the University of East Anglia admitted to "adjusting" the data, we cannot be sure that any outcome predicted by the computer can be in any way trusted.
Unfortunatley, to air that legitimate view is to be called a "denier". But consider this, is it not the same to argue that anyone who accepts conclusions derived from dodgy data also a denier?
Remember the first law of computing
GARBAGE IN= GARBAGE OUT.