Tuesday, March 10, 2009

An Inconvenient Reversal of Trend?

Al Gore's now infamous movie title may have an interesting twist. The truth may be that trends in global temperatures have reversed. From NASA, here are the most recent facts:

This figure has its own set of issues. But, let's take as given that we are warmer today than in 1950 (the base year for this figure). The black line tracks the annual observations of this index while the red line shows the 5-year mean (presumably to measure the longer term trend in the index). What we see is that we peaked several years ago, and the longer-term trend is now moving downward. This, of course, does not mean that the trend has permanently reversed, but calls into question the notion that temperatures are perpetually increasing. On the contrary, there appears to have been relatively steep increases in this index during the 1990s, but the rate of climb fell of sharply in the late 1990s-early 2000s, and now has actually gone negative (temperatures on the decline).

Lest we focus too much on the global picture at the expense of more specific regions, the figure above breaks the data down by latitude bands. Note that the Northern latitudes have experienced the greatest degree of "warming," which may lend some support to man-made causes (the area with the most industrial activity), but note that all areas are experiences the same reversal of trend.

The above figure shows land and sea temperature changes. Note again that both land and sea are reversing course in temperature. Just an interesting observation is that the sea temperature change appears greater in percentage terms as compared to land and also appears to lead temperature changes on land... That might make an interesting testable hypothesis.

Bottom line...is the trend in global temperatures reversing?? Who knows? Not Al Gore. But, these data will not appear in the mainstream media because it runs counter to the goals and objectives of the liberal left. But more disturbing is how the scientific community has abandoned its principles in this debate.

Some may question why we should care whether the issue of global warming is real or fabricated. The answer is that proposed solutions have costs (see Wall Street Journal editorial or Fox News story that summarizes a complex text produced by the EPA). I suspect, but have no direct evidence, that many of the people most pushing the global warming agenda are heavily invested financially (as well as emotionally) in companies that stand to profit from a move to reduce carbon emissions. I guess we will find out what is going on later....

"There are three types of lies. Lies, damned lies, and statistics."

--Benjamin Disraeli