Tuesday, February 12, 2008

January was Cool (and Extraordinary)!

The world's climate experienced an extraordinary series of events in January. But these events didn't include Baghdad first snowfall in living memory or Jerusalem's snowfall or even China's worst winter weather in half a century. And it wasn't the fact that the global temperature anomaly (according to NOAA) was .1793 degrees Celsius since such a figure suggests that the global temperature in January was warmer than the average for the 1901 to 2000 period (the base period for the NOAA temperature anomaly series). Even the fact that January's anomaly was the second lowest recorded since January of 2000 wasn't particularly noteworthy.

One extraordinary event was the fact that January's anomaly was .6521 degrees colder than the record .8314 degree anomaly recorded in January of 2007. That's extraordinary, you may ask? Absolutely. This .6521 degree decline was the greatest recorded over a 12-month period in the 128-year history of the NOAA time series. In only two other months since January of 1880 has a year-on-year temperature decline greater than .5 degrees been recorded. This record decline was recorded in the absence of major globa-scale volcanic activity and instead exceeded global declines recorded during the late 19-century (a period of the most intense volcanic activity recorded on this planet over the past 150 years) and declines recorded in the early 1990's in the wake of the Pinatubo and Hudson volcanic eruptions.

Another extraordinary event was January's month-on-month decline of .2182 degrees coupled with month-on-month declines recorded in the previous three months in a row. An anomaly decline of greater than .2 degrees on a month-on-month basis is relatively rare (about once every 25 months on average) but recording such a large decline after three straight months of anomaly declines had never previously been observed in the NOAA temperature anomaly time series.

Finally, the total temperature anomaly decline over the three months prior to January was .1314 degrees. The only time since 1880 when a month-on-month anomaly decline of greater than .2 degrees was preceeded by a greater anomaly decline in the previous three months occurred in January of 1893 during a period of significant volcanic activity. In fact, on only five (of 60) occasions since 1880 has a decline of greater than .2 degrees taken place in the wake of a negative total change in the anomaly in the previous three months.

What do we make of these extraordinary events? We have noted in other postings that symmetric numerical patterns in the global temperature anomaly are associated with long-term broad temperature movements. While I also argue that the temperature anomaly record contains clear evidence of anthropogenic-induced warming, natural temperature movements still appear to dominate over human effects. Thus, the temperature decline over the past year may signal the beginning of a period of global temperature decline. If this is even remotely correct, the current consensus on climate will shortly be due for a major review.

Stay tuned . . . . .

Further thoughts on the above:

It is frequently argued that the anthropogenic warming signal has emerged out of the "fog" of natural variation over the past 30 years. It is also frequently argued that the amount of natural variation over the past 30 years (indeed the last 50 years as argued by the IPCC reports) is so minimal that most of the observed warming over this period must be the result of human activity. We also know (as noted above) that the most significant temperature decline episode during the past 30 years resulted from the combined effects of the Pinatubo and Hudson volcanic eruptions. So we have an explanation for the decline observed at that time. However, there is no explanation in the consensus paradigm that comfortably fits in with the precipitous temperature decline observed over the past year since no major volcanic eruption thought to affect global climate has taken place over the past year. In addition, potential speculation that aerosols might be responsible for the cooling would ignore the fact that such precipitous cooling should require a massive short term increase in the level of aerosols emitted to the atmosphere to cause such a cooling. There is no question that China's and India's aerosol emissions are significant and increasing but it is difficult to imagine that they have increased significantly enough in the past 12 months to produce the observed decline in average global temperatures.

So we are left with a dilemna - either the observed cooling over the past 12 months results from some as-yet-not-understood human-induced phenomena or this cooling is taking place because of some natural factors not in any way included in current consensus scientific modeling.

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