According to Wikipedia, the Dark Ages is a term referring to a period of cultural decline or societal collapse that took place in Western Europe between the fall of Rome and the eventual recovery of learning. The concept of a Dark Age was created by the Italian scholar Petrarch (Francesco Petrarca) in the 1330s and was originally intended as a sweeping criticism of the character of Late Latin literature.
But did you also know that it really was dark?
The sun's brightness hasn't changed much over the last 20 years. But it has been brighter for the last 60 years than it has been at any time in the last 1,150 years. Consider the following:
According to scientists, the Sun's radiance has changed little during this period [60 years]. But looking back over 1,150 years, Sami Solanki [Professor at the Federal Institute of Technology in Zurich Switzerland] found the Sun had never been as bright as in the past 60 years.
The team studied sunspot data going back several hundred years. They found that a dearth of sunspots signaled a cold period - which could last up to 50 years - but that over the past century their numbers had increased as the Earth's climate grew steadily warmer. The scientists also compared data from ice samples collected during an expedition to Greenland in 1991. The most recent samples contained the lowest recorded levels of beryllium 10 for more than 1,000 years. Beryllium 10 is a particle created by cosmic rays that decreases in the Earth's atmosphere as the magnetic energy from the Sun increases. Scientists can currently trace beryllium 10 levels back 1,150 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.
The history of our planet is one of thawing and freezing and thawing again. The planet itself records the fact that for most of its existence demonstrates this kind of cycle. And although our blue planet is warm and comfy most of the time, it has spent an enormous amount of time in some form of an ice age.
And if one were to look at sunspot cycles, it is apparent that increased solar activity warms the Earth and decreased solar activity allows the Earth to cool. These are simple and demonstrated truths.
If you were to take this to its logical end, the higher solar activity in the last 60 years is a "peak" of the sun over a 1,000 year period. This means that there should be an expected natural warming of the planet with a subsequent cooling cycle. Since sunspots and solar surface activity eludes predictive methodologies, it is unclear at any time what may happen 60 or 100 or 1000 years from now.
But what should be obvious is that the sun is expected to start a downward trend of solar activity at any time, or already has. Once the downward trend begins, we will have a new minimum similar to the Maunder Minimum with decades of much colder weather.
Or conversely, the sun could crank up the surface activity and solar flares and sunspots increase dramatically. In the event solar activity increases further, the Earth will see temperatures rise more than what models predict for consequences of greenhouse gases.
The long and short of it is that Sun has just peaked. It is little wonder that there has been a 4 degree increase in temperatures over the last 100 years. My bet is the next 100 years will see the cycle begin again and the Earth will begin to cool, just as it has done for eons without any help at all from us.
Copyright 2009, Kevin Farley (a.k.a. sixdrift, a.k.a. neuronstatic)
