Global Wobbling?

As if global warming by greenhouse gases (human or volcanic) isn't enough, throw in some not-quite-periodic ice ages, a slightly variable sun, and now ... global wobbling. You just can't trust the climate anymore.

The Earth doesn't spin with perfect precision. The pole is known to wobble in a variety of ways. Most of these changes are a few meters or less, but we now have the tools to measure them precisely. As for the exact cause, well ...

A Mystery Of Earth's Wobble Solved: It's The Ocean (LINK - ScienceDaily, 18 Jul 2000)

Changes In The Earth's Rotation Are In The Wind (LINK - ScienceDaily, 6 Mar 2003)

To be fair, the first article says it's 2/3 ocean and 1/3 atmosphere, and is talking specifically about the Chandler wobble which has a period of 433 days. The second is not clear which wobble it's talking about. Here's a fascinating piece ... the Chandler wobble and an annual wobble cancel out every 6.4 years, allowing a team to track and even smaller wobble at the centimeter scale:

Tracking Earth's Wobbles Down To The Size Of A Cell Phone (LINK - ScienceDaily, 26 Jun 2006)

Some scientists are seriously studying whether there is a larger wobble on a scale of hundreds of miles (a few degrees), which might affect the global climate.

Study Links Extinction Cycles to Changes in Earth’s Orbit and Tilt (LINK - NYTimes, 12 Oct 2006)

And here's a parody that's good for a grin:

Global Wobbling: An Inconvenient Truth (LINK - ConservativeVoice, 15 Oct 2006)