09 November 2011

Paragraphs to Ponder

David Deming, on global warming:
Have you ever considered how difficult it is to take the temperature of the planet Earth? What temperature will you measure? The air? The surface of the Earth absorbs more than twice as much incident heat from the Sun than the air. But if you measure the temperature of the surface, what surface are you going to measure? The solid Earth or the oceans? There is twice as much water as land on Earth. If you decide to measure water temperature, at what depth will you take the measurements? How will the time scale on which the deep ocean mixes with the shallow affect your measurements? And how, pray tell, will you determine what the average water temperature was for the South Pacific Ocean a hundred years ago? How will you combine air, land, and sea temperature measurements? Even if you use only meteorological measurements of air temperature, how will you compensate for changes in latitude, elevation, and land use?
Determining a mean planetary temperature is not straightforward, but an extremely complicated problem. Even the best data are suspect. Anthony Watts and his colleagues have surveyed 82.5 percent of stations in the U.S. Historical Climatology Network. They have found – shockingly – that over 70 percent of these stations are likely to be contaminated by errors greater than 2 deg C [3.6 deg F]. Of the remaining stations, 21.5 percent have inherent errors greater than 1 deg C. The alleged degree of global warming over the past 150 years is less than 1 deg C. Yet even in a technologically advanced country like the US, the inherent error in over 90 percent of the surveyed meteorological stations is greater than the putative signal. And these errors are not random, but systematically reflect a warming bias related to urbanization. Watts has documented countless instances of air temperature sensors located next to air conditioning vents or in the middle of asphalt parking lots. A typical scenario is that a temperature sensor that was in the middle of a pasture a hundred years ago is now surrounded by a concrete jungle. Urbanization has been a unidirectional process. It is entirely plausible – even likely – that all of the temperature rise that has been inferred from the data is an artifact that reflects the growth of urban heat islands.
The ultimate problem with the case for global warming is that the data is insufficient and highly biased.  Samples, though possibly indicative of global change, are not proof of global change.  They are only proof of local change (i.e. on can only say with certainty that temperatures have risen over time at specific locations).  It is possible that temperatures may have decreased or remained stagnant at locations where temperatures were not taken.  Scientists are not able to measure temperatures of the entire earth all the time, and cannot therefore say that the entire earth’s temperature has changed one way or the other.

Beyond that, though, the current—and highly limited—method of taking temperatures has a bias toward high temps.  Yet this bias is often ignored in research, leading to shrill proclamations of doomsday.  Thus, the case for global warming is based on very limited data, which is biased towards high temps to boot.
Global warming predictions cannot be tested with mathematical models. It is impossible to validate computer models of complex natural systems. The only way to corroborate such models is to compare model predictions with what will happen in a hundred years. And one such result by itself won't be significant because of the possible compounding effects of other variables in the climate system. The experiment will have to repeated over several one-hundred year cycles. In other words, the theory of catastrophic global warming cannot be tested or empirically corroborated in a human time frame.
Computer models only prove what programmers program to prove.  Their validity is solely contingent on the accuracy of the assumptions about the variables, such as which specific variables to test, their relevance, and their relation to one another.  If any of the assumptions are wrong, the model is worthless.  Therefore, models are pointless for proof.  Their main use is in creating a prediction, which can then be compared to the real world.

Consider this as well:
Finally, I'm happy to be known as a "denier" because the label of "denier" says nothing about me, but everything about the person making the charge. Scientific theories are never denied or believed, they are only corroborated or falsified. Scientific knowledge, by its very nature, is provisional and subject to revision. The provisional nature of scientific knowledge is a necessary consequence of the epistemological basis of science. Science is based on observation. We never have all the data. As our body of data grows, our theories and ideas must necessarily evolve. Anyone who thinks scientific knowledge is final and complete must necessarily endorse as a corollary the absurd proposition that the process of history has stopped.
A scientific theory cannot be "denied." Only a belief can be denied. The person who uses the word "denier" thus reveals that they hold global warming as a belief, not a scientific theory. Beliefs are the basis of revealed religion. Revelations cannot be corroborated or studied in the laboratory, so religions are based on dogmatic beliefs conservatively held. Religions tend to be closed systems of belief that reject criticism. But the sciences are open systems of knowledge that welcome criticism. I'm a scientist, and therefore I must happily confess to being a denier.

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