[this is a copy of my second post as a guest on Vie Hebdomadaires]
It’s been a heavy day, time is short, and I’m afraid it’s not going to be a long post tonight.
On Sunday, my friend Gayle Reynolds alerted me to advance publicity for release of the Berkeley Earth Surface Temperature (BEST) study. Yesterday, the results were made available so I duly collected a copy but didn’t get a chance to read it until today.
BEST analyses temperature data over a period of more than two hundred and fifty years. Though its declared aim to make a transparent database of records, calculations, methods and results publicly available is valuable in itself, the view has been obscured by a blizzard of accusations and counter accusations flying in both directions between the climate change accepters and sceptics, additionally fuelled by funding from sources associated with aggressive global warming denial.
In the event, the report firmly underwrites the anthropocentric temperature increase model and can find “… no significant correlation between the land surface temperature history of the last 250 years and the solar forcing history…”
And along with the report I’ve downloaded the data sets (they are , as promised, publicly available on the BEST site), so that I can play with them myself over the weeks ahead … which, in itself, makes this a good day.
- Felix
An externality, to an economist, is[1] "a side-effect or consequence ... which affects other parties without this being reflected in the cost of the goods or services involved". Externalities take all sorts of forms, and can be positive or negative, but over the past half century industrial pollution of the environment has become the primary exemplar.
More recently still, the focus has narrowed down to carbon based compounds whose costs are paid in a number of ways. The crudest direct health effects are usually localised, and become a matter for local legislation or lack of it; the atmospheric greenhouse effect is a global issue with no respect for human jurisdictional boundaries.
Attempts to deal with pollution almost always come down to mechanisms designed to convert an externality into a direct cost paid by the polluter, and carbon is no exception. A number of schemes exist to license carbon emission, with a market in which those who emit least sell permissions to those who emit most, thus exerting a direct proportional cost pressure on producers.
Whether this method is effective, and if so to what degree, is a subject of considerable political argument; but it remains the principle approach. Its use depends on quantification of emissions, which is neither simple nor straightforward. In practice, output is usually simplified from the full gamut of emitted substances (not all of them carbon based) to a single carbon dioxide equivalence figure, the product of mass and a radiative forcing factor which varies from substance to substance. But that still leaves an impractically large data acquisition and monitoring task.
The essence of statistical data analysis, always and everywhere, is generalisation from sample to population with a quantified level of confidence. Sometimes, as with extraterrestrial exploration in the last issue, this is because only tiny amounts of data can be captured and the maximum information must be squeezed from it. In the case of planetary emission levels the opposite is true: the available data volume is huge, and only a small fraction of it can be manageably handled. [more]
1. Oxford English Dictionary, Oxford University Press.
