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Saturday, December 27, 2014

It's Going to Get Warmer

Skeptics like to pick random data to “prove” their point, such as declaring that Global Warming stopped in the late Nineties. Of course, that only fools other deniers. Certainly, it is the case that air temperatures have had a flat period from 1998 to 2014. But, overall global temperatures have continued to rise in the oceans, which have absorbed the excess heating of Global Warming for the past seventeen years.

That's coming to an end, however. The oceans are beginning to give us back all that heat in a big way. The reason is that the Pacific Ocean has been in the negative (cool) phase of the Pacific Decadal Oscillation (PDO). The PDO tends to run a couple of decades in the negative phase, then another few decades in the positive (warm) phase. It has been studied extensively and its current negative phase is powerful enough to suppress El Ninos. It also brings extensive drought to the American Southwest. We've certainly seen quite a bit of drought in the last several years.

Theodor Landscheidt studied cycles of the PDO before he passed away several years ago. He was particularly interested in understanding how the cycles of the sun affected our weather. He created a model of the PDO and published it online in Long-Range Forecast of U.S. Drought Based on Solar Activity. In that paper, he predicted that we would be suffering drought under the influence of the negative (cool) phase of the PDO until early 2016. He was correct in that prediction to date—but is his prediction of 2016 on target still?

We may be seeing a phase transition in the PDO from negative to positive right now, almost two years earlier than his prediction. Axel Timmermann of the University of Hawaii and Kevin Trenberth of the US National Center for Atmospheric Research are suggesting we may be seeing the PDO turn positive in Warming Pacific Drives Global Temperatures:

Both men stress that there are a number of different factors at play. However, the sequence of events that has contributed to the current situation is becoming clear. The negative IPO phase in place since the late 1990s led to very strong equatorial trade winds – which are separate from the classical trade winds that blow across the Pacific north and south of the equator. “These cooling equatorial trade winds were so strong that they sucked up water from the eastern equatorial Pacific and moved it west,” said Timmermann.

The result was that equatorial Pacific cooled and the sea level in the western Pacific rose much faster than the global average rate – and the cooling Pacific sea surface waters cooled the atmosphere above them and so caused the pause. “So the trade winds intensified, the equatorial Pacific cooled, sea levels in the west rose and this all goes together with the global warming hiatus,” explained Timmermann.

This period of strong equatorial trade winds came to an end at the beginning of 2014 resulting in a warming in the northern Pacific and especially along Alaskan coastal waters.

Next, a series of waves of warm water – known as Kelvin waves – moved across the Pacific from the west near Indonesia to the east and these were interpreted as signs that an El Nino Pacific Ocean warming event may be about to take place. Trenberth explained to reportingclimatescience.com that, as a result of this movement of water, sea levels rose in the central and eastern Pacific and fell back in the western Pacific. However, this warm water did not trigger the expected full blown El Nino.

Instead, the warm water moved across the Pacific until it hit the western coast of the Americas and moved north and south – warming coastal waters along the west coast of North America as far north as Oregon and causing a warming of the north eastern Pacific Ocean waters from April through to September.

Finally, over the last three months or so the classical trade winds started to weaken too. Normally they act to cool the ocean. This time the trade winds weakened considerably and the cooling ceased almost completely. This intensified warming in the central Pacific.

Results

So during 2014 the waters of the northern, north eastern and central Pacific have all warmed significantly. This has had the effect of raising the global average surface temperature to record levels which will almost certainly result in 2014 being reported as the warmest year on record.

Trenberth explained that there have been widespread impacts on the weather as storm systems – such as the recent Typhoon Nuri - moved further northwards than usual, drought conditions in California persist while a mass of cold air moved south across central and eastern North America in November.

Meanwhile waters off the coast of Hawaii reached 29°C or 30°C through the summer, according to Timmermann, causing corals to die and bleach. “We have seen temperature anomalies of 4°C in some area – very extreme. This warming is bad news for salmon fisheries and also for coral. Fish and sea life are experiencing this year what we are projecting for 100 years time,” said Timmermann.

The hiatus in global warming of air temperatures is either over now or will be over very soon. This will cement public opinion concerning Global Warming and create a consensus that we have to do something about the problem, rather than letting it fester as we have for the last few decades.

The good news? Fighting Global Warming will create many new jobs and will stimulate the economy. We've all heard about the bad news of Global Warming. Take heart that the effort to rollback the warming will create many, many jobs to boost the economy in coming years.