Geographers define an Ice Age as a period in Earths history when there are polar ice caps. That means that for all intents and purposes we are still in the middle of an Ice Age. The fact that ice caps are still present at the poles is the sure indication that the period is not yet run its course. There have been times in the history of this planet when there is no large scale permanent ice present at the extremes, but this isn’t one of them. Our current climate is described as interglacial and this is where many people get confused Interglacial does not mean “between Ice Ages” it just refers to a time when the caps are retreating due to warmer temperatures. The age may be moving slowly towards an end, but it is not over yet. This reduction in the amount of ice and the gradual rise in temperature may be the main aspect that gets referred to as global warming, a basically natural phenomena, but it is not within the scope of this piece to discuss the politics of that.
Our interglacial started 10,000 years ago in what we think is the Fourth Ice Age, and with it came the rise of humanity as a dominant species. When will the interglacial period end? Will we be plunged back into another Ice Age? Will the polar caps disappear altogether? Its difficult to say as the science of Ice Ages is not fully mastered yet and many theories abound. These fluctuations in and out of deep ice dominated periods and warmer periods are not fully understood. Possible factors include the position of the continental land masses, the composition of the atmosphere, changes to the Earths orbit around the Sun and maybe even changes in the Suns own orbit around the galaxy.
There have been various “cold snaps” within this gradual warming, the last being the “Little Ice Age” which lasted 300 years from 1500AD. During this period the average temperature in Northern Europe dropped by 1 degree C, which also coincided with a period of low sunspot activity, whether the two are directly linked has not been firmly established. During this period, the Artic Ice Sheet extended so far south that Eskimos were able to reach Scotland in kayaks on 6 different recorded occasions and the inhabitants of the Orkneys had to fight off a disorientated polar bear.
There has been a link made in recent research between the Little Ice Age and the Black Death. The Black Death led to the drastic decline in population in Europe which in turn led to the abandonment of large tracts of farmland, which would have gradually been covered by millions of trees. This may have led to the significant absorption of carbon dioxide from the atmosphere, resulting in an “anti-greenhouse effect” and therefore a drop in temperature.
