Margin of Error and Global Warming
How do we obtain an accurate measure of the several forces at work affecting our climate? We have just been reminded that cloud cover is impossible to properly model at all. This means that whatever factor or function is assigned to its effect, its statistical error range will be huge.
For any given point of earth, the local temperature can already be safely written as T + or – 50 degrees F. Ocean temperature is very consistent but its volumetric flow rate is anyone’s guess. Remember that we measured the apparent volume of the Gulf Stream recently and found it had apparently declined by around forty percent since 1957. With two data points, we have no clue if it is significant. More recent work suggests that the effect is much more variable than we ever guessed.
I think that the important conclusion that we can draw is that the globe has several mechanisms whose variation within their natural range are quite capable of shifting global temperature around in the order of magnitudes that we are experiencing and have experienced historically. These same mechanisms also must move to moderate any such temperature variation. The sense is that if a trend goes too far in one direction, counter balancing triggers kick in and a lot sooner than is obvious.
We recap the mechanisms:
We have the man made direct impact of particulate production that is allowing more heat to be absorbed by the atmosphere.
We have the warming of the North Pole if sustained will eventually induce a warmer and perhaps wetter arctic.
We have agriculture, which has historically been a releaser of carbon, perhaps now about to become the major collector of all the carbon ever produced and perhaps a much larger absorber of solar energy through expansion into the deserts..
We have the speculation that cold water from the South Atlantic has periodically been injected into the Atlantic with major chilling effects on Europe and North America. The south polar sea is the primary engine of cooling on this planet because of the unusual location of Antarctica and the related circum polar current. Recall that all the cold water available for cooling in the Pacific comes from Antarctia.
Last but not least we may have the possible impact of the greenhouse mechanism.
Those are a lot of levers to juggle in any atmospheric model. And we truly need a thousand years of data to secure any knowledge that we can trust. What we have now is the knowledge that it has been hotter and it has been colder.
In the meantime, the best that we can hope to do is to regulate our global society to eliminate non carbon atmospheric pollution and to sequester carbon in all agricultural croplands as an economic bonus. And as an extra bonus, we want to grow forests on all the dry lands which will nicely double the amount of land under tree cover, absorbing solar energy and using it to sequester carbon.