Look at this chart http://www.pbase.com/azleader/image/155647211.jpg

The recent changes in temperature can be modelled by combining a steady rise and an oscillatory signal. The PDO might be responsible for the oscillatory part but not the steady trend.

Cynics might argue that the rising trend is mainly down to the various temperature "corrections"; others will claim it is genuine. The PDO will suppress the trend half the time and enhance it for the other half.

The alarmists were happy when the oceans reinforced the trend claiming it was a sign of CO2-based global warming. Now the oceans are suppressing the trend they are at a bit of a loss. When the upswing returns they will, once more, be claiming they were right all along and the pause was just a figment of our imagination.

The Pacific Decadal Oscillation (PDO) is the leading EOF of monthly sea surface temperature anomalies (SSTA) over the North Pacific (poleward of 20° N) after the global mean SSTA has been removed, the PDO index is the standardized principal component time series.

The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of 20° N. During a "warm", or "positive", phase, the west Pacific becomes cool and part of the eastern ocean warms; during a "cool" or "negative" phase, the opposite pattern occurs. It shifts phases on at least inter-decadal time scale, usually about 20 to 30 years.

The Pacific (inter-)decadal oscillation was named by Steven R. Hare, who noticed it while studying salmon production pattern results in 1997.

The prevailing hypothesis is that the PDO is caused by a "reddening" of the El Ni?o–Southern Oscillation (ENSO) combined with stochastic atmospheric forcing.

A PDO signal has been reconstructed to 1661 through tree-ring chronologies in the Baja California area.

That is not physically possible.

By what mechanism do you suggest that the EOF of SST anomalies in the North Pacific (PDO) could drive global climate change? Does it have some magical power that taps into energy from a parallel universe?



How can the PDO be the cause of climate change when the 1997/98 El Nino caused the PDO to shift phases?

You are aware that since 1900 we have only seen two complete PDO cycles – aren’t you?

These ocean current patterns affect how much cold water is churned to the surface. When icy cold water is churned from the ocean depths, the troposphere is cooled as more heat moves from the air to the oceans. The PDO and ENSO do certainly affect the temperature of the troposphere on an annual or even near-decadal basis, but they do not affect the total heat retained in the environment between the oceans and air.

It's the Pacific Decadal OSCILLATION. Do you know what an oscillation is? The PDO is probably masking the effects of the warming now and it probably made the warming look more rapid during its positive phase. The point is that it doesn't CHANGE the climate.

Yep! The climate is changing, but those changes are occurring, have always occurred, and always will occur. We don't need "climate science engineers" to tell people it is our fault without "quantifying" the effect they have on temperatures based on a "preponderance of the evidence". "Preponderance of the evidence" suggests that we are in a natural warming phase, but "climate science engineers" are "engineering" their own scenario through the IP CC without the help of scientists who question their motives. Research money is being literally thrown at them to prove that CO2 is causing "Global Warming". It's the basis of their motivation.

The PDO is only one of many factors that helps "make" the climate shift. It would be great if "climate science engineers" would simply call them "climate shifts", then actually identify each individual "effect" that makes the climate shift, and then by the process of "subtraction" they could help people understand what their actual and overall effect on the climate really is. Unfortunately, there are environmental "climate science engineers" who are trying to control people's actions based on their own environmental bias. They have been trying to become the new "Robin Hoods" (stealing from the rich and wanting to save the world, instead of helping the poor), but their agenda has been very clear from the start.

PDO is basically something that helps temperatures (energy) flow around the world. I hope it never stops as I hope the same for the AMO, water cycle, carbon cycle, solar fluctuations, etc... :-)

The earth is warming regardless of what's happening in the Pacific. The PDO simply complicates the picture. When the PDO is cooling (like it has been for the last 14 years), there is little or no warming. When the PDO is warming, the global temperature goes up relatively quickly. If you extrapolate from one of the warming cycles, you get a really scary looking graph of out of control warming. That's what the climate scientists did with their billions of funding and super computers. If you overlay the PDO on top of the long term trend, you get an accurate picture.

Unfortunately, this picture is not scary enough to merit funding at current levels.