Global Cooling

I was reading the Netscape Blog today and came across an interesting post on the politicization of climate science. They report:

More than 120 scientists across seven federal agencies say they have been pressured to remove references to "climate change" and "global warming" from a range of documents, including press releases and communications with Congress.

As usual there is a Usenet type discussion going on. Flame wars (not too bad - Netscape is somewhat moderated). And just people with out a clue. Fun to visit. On the odd occasion.

So out of that discussion I pulled a couple of interesting urls.

The first is from Russia

ST. PETERSBURG, August 25 (RIA Novosti)- Global cooling could develop on Earth in 50 years and have serious consequences before it is replaced by a period of warming in the early 22nd century, a Russian scientist said Friday.

Environmentalists and scientists today focus on the dangers of global warming provoked by man's detrimental effect on the planet's climate, but global cooling - though never widely supported - is a theory postulating an overwhelming cooling of the Earth which could involve glaciation.

"On the basis of our [solar emission] research, we developed a scenario of a global cooling of the Earth's climate by the middle of this century and the beginning of a regular 200-year-long cycle of the climate's global warming at the start of the 22nd century," said the head of the space research sector of the Russian Academy of Sciences' astronomical observatory.

Khabibullo Abdusamatov said he and his colleagues had concluded that a period of global cooling similar to one seen in the late 17th century - when canals froze in the Netherlands and people had to leave their dwellings in Greenland - could start in 2012-2015 and reach its peak in 2055-2060.

I first did a piece on increased solar output in November of 2004. In that piece I suggested that the global warming we have been experiencing is mainly due to increased solar output. Since then further reports have come out adding more weight to the evidence.

Here is a report with links showing the connection between solar activity and climate for the last 1,000 years.

During the Medieval maximum of 1000-1300 there was an extremely large Sunspot which is believed to have warmed the Earth higher than normal. There were no accurate measurements of the weather to call upon during this time but the discovery and colonization of Greenland by Eric the Red supports this hypothesis. Eric was exiled from Iceland for manslaughter and sailed west discovering Greenland. He then led many ships, filled with people who wanted to make a fresh start, to this new land. For 300 years Greenland flourished, new communities settled, trade with other countries grew, and the population increased. Around 1325 the climate cooled down considerably, people started to abandon the northern settlements. By 1350 glaciers covered the northern settlements, and the southern most settlements were dying out as well.

The Sporer minimum of 1400-1510 and the Maunder minimum of 1645-1715 were each known as a "little ice age." They were both droughts in Sunspot activity, and a link to a time of abnormally cold weather on Earth. In addition to finishing off the Greenland colonies, the Sporer minimum showed increased rates of famine in the world, and the Baltic Sea froze solid in the winter of 1422-23. Some of the more notable effects of the Maunder minimum included the appearance of glaciers in the Alps advancing farther southward, the north sea froze, and in London there was the famous year without a summer where it remained cold for 21 consecutive months.

That was posted in 2004. What did the poster expect for the future?

The Sun could start going through a down trend in sunspot activity at any time. We could find ourselves back in a state similar to the Maunder Minimum with decades of much colder weather. Or sunspot activity could increase to an even higher level and temperatures could rise more than the amount some models project as a consequence of higher atmospheric carbon dioxide.

My guess is that the chances are greater for a reduction in sunspot activity than for an increase. Why? Most of the time the planet Earth is in an ice age. This is suggestive of the possibility that the Sun just doesn't put out enough heat to keep the Earth out of ice ages most of the time. Also, the higher sunspot activity reported above is at the high end of an over 1,000 year period. Therefore the odds seem greater that we will have more future years with lower sunspot activity than with higher sunspot activity.

My further guess is that a reduction in sunspot activity would cause more harm to humans than a further increase in sunspot activity. A decrease could put large amounts of farm fields out of production and would reduce the useful length of the growing seasons for other fields. The freezing over of rivers and seas along with snows and ice would interfere with transportation more than higher temperatures would.

Which is exacly what is being predicted by the Russian scientist.

He is not alone.

The New Scientist report, along with other scientific assessments warning of global cooling, also come as a blow to the campaign -- led by David Suzuki and one of the directors of his foundation -- to portray all who raise doubts about climate change theory -- so-called skeptics -- as pawns of corporate PR thugs manipulating opinion. If the Suzuki claim is true, then the tentacles of Exxon-Mobil reach deeper into science than anyone has so far imagined.

Dramatic global temperature fluctuations, as New Scientist reports, are the norm. A Little Ice Age struck Europe in the 17th century. New Yorkers once walked from Manhattan to Staten Island across a frozen harbour. About 200 years earlier, New Scientist reminds us, a sharp downturn in temperatures turned fertile Greenland into Arctic wasteland.

These and other temperature swings corresponded with changing solar activity. "It's a boom-bust system, and I expect a crash soon," says Nigel Weiss, a solar physicist at the University of Cambridge. Scientists cannot say precisely how big the coming cooling will be, but it could at minimum be enough to offset the current theoretical impact of man-made global warming. Sam Solanki, of the Max Planck Institute for Solar System Research in Germany, says declining solar activity could drop global temperatures by 0.2 degrees Celsius. "It might not sound like much," says New Scientist writer Stuart Clark, "but this temperature reversal would be as big as the most optimistic estimate of the results of restricting greenhouse-gas emissions until 2050 in line with the Kyoto protocol."

Funny thing is that solar output is not handled well in current climate change models.

That was discussed at length at Winds of Change. In fact the discussion basically evicerates the whole cimate change modeling community for over promising on the reliability of their results.

The more I look into this the more I find it is old news. From October of 2000 Proceedings of the National Academy of Sciences (USA).

Although the processes of climate change are not completely understood, an important causal candidate is variation in total solar output. Reported cycles in various climate-proxy data show a tendency to emulate a fundamental harmonic sequence of a basic solar-cycle length (11 years) multiplied by 2^N (where N equals a positive or negative integer). A simple additive model for total solar-output variations was developed by superimposing a progression of fundamental harmonic cycles with slightly increasing amplitudes. The timeline of the model was calibrated to the Pleistocene/Holocene boundary at 9,000 years before present. The calibrated model was compared with geophysical, archaeological, and historical evidence of warm or cold climates during the Holocene. The evidence of periods of several centuries of cooler climates worldwide called "little ice ages," similar to the period anno Domini (A.D.) 1280-1860 and reoccurring approximately every 1,300 years, corresponds well with fluctuations in modeled solar output. A more detailed examination of the climate sensitive history of the last 1,000 years further supports the model. Extrapolation of the model into the future suggests a gradual cooling during the next few centuries with intermittent minor warmups and a return to near little-ice-age conditions within the next 500 years. This cool period then may be followed approximately 1,500 years from now by a return to altithermal conditions similar to the previous Holocene Maximum.

You have to ask yourself, why isn't this being discussed? Why wasn't it in Al Gore's movie on climate? Which I'm told is set to recieve an Oscar this year. I'm willing to bet Gore's movie An Inconvenient Truth will go down with Leni Riefenstahl's Triumph of the Will. A triumph of propaganda.

More on the 1,500 year solar cycle



Cross Posted at Classical Values