Friday, November 20, 2009

Stalled Warming Or Started Cooling

SEARCH BLOG: GLOBAL WARMING

From Anthony Watts' blog, Watts Up With That?
Der Spiegel Online: stagnating temperatures a puzzle 20 11 2009

Stagnating Temperatures

Climatologists Baffled by Global Warming Time-Out

By Gerald Traufetter

Global warming appears to have stalled. Climatologists are puzzled as to why average global temperatures have stopped rising over the last 10 years. Some attribute the trend to a lack of sunspots, while others explain it through ocean currents.

In the two-part analysis of climate recently posted...
... the concluding chart provides some insight into the possible answer to Der Spiegel's quandry.
With this in mind, let us look again at the chart depicting the first 2 decades of the 21st century as a repeat of the 1960s and 1970s, but overlay a pattern of multiple sloped steps:
Note that virtually all of the warming can be attributed to less negative variance versus the early part of the century. This is consistent with loss of rural reporting stations and general urbanization, not because maximum temperatures have been increasing, and could explain some of the lack of significant negative anomalies in the last half of the 20th century.

We already have some indication of a cooling period beginning. If it does continue, perhaps the declaration of global warming requires additional evaluation.

Nature tends to avoid simple or linear processes.

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