There are two theories as to how our world came into being; that of creation and that of geology. One theorises that the Earth, over billions of years, gradually cools from a molten ball of hot magma that allowed the world we know to develop, the other theorises that it was created in seven days by a God and is around seven thousand years old. They are mutually exclusive ideas neither one lending credence to the other and it is an unfortunate trait of human nature that neither one of these separated ideas can be entertained by the opposing view point. That, however, is an argument for another time. Tonight's feature, Earth: The Biography, takes a look at the latter theory and tries to explain scientifically how our world came into being and what forces have shaped it throughout its interminably long life span.
Dr Iain Stewart takes us on a journey through time from the birth of our planet right up to the present day telling the story of how the forces of nature, or otherwise, have helped shaped the world and bring it to the lush green and water filled place we know today. The programme is split into five parts, each concentrating on a specific area of nature which are: Volcanoes, Atmosphere, Ice, Oceans and Rare Planet; this last episode is a summation of all that has gone before explaining how unique our world really is.
In the first episode, Volcanoes, we are treated to the world most ferocious power and Stewart informs us of the natural balance these might behemoths of destruction are to the survival of life, and how they were responsible for life in the first place, either from volcanic pools, black smokers or both. Whilst there is a modicum of stock footage most of the material is newly filmed; I was particularly impressed with the interior of the caldera with its bubbling lava analogous to the tectonic plates and indeed the very early surface of the planet. He describes, in easy detail, how plate tectonics work, construction and subduction and how the raw building blocks of our atmosphere and life are contained within the molten rock. A good balance was stuck between scientific fact and conjecture and all backed up with some stunningly good photography and CG graphics.
Following this is Atmosphere; during this episode Stewart takes a flight in one of the fastest planes in the world to explain about the four layers of our atmosphere. Explanations of how our atmosphere came about are given right down to the introduction of oxygen and the Banded Iron Formations that mark it in the geological record. The introduction of oxygen was the most important development for life on Earth, not simply because every organism needs it to breath but it also provides us with the ozone layer that protects the surface from UV light. Visits to the rainforest coupled with satellite images of the blue-green algae in the sea demonstrate how the oxygen supply is replenished and how that carbon dioxide is so important in keeping the planet warm; that without it the world would freeze. I was particularly impressed with the frozen methane section and how that if the Earth temperature raised significantly they will be released to potentially devastating effect; methane is four times more powerful as a greenhouse gas than CO2. This is one of the very few programmes of this type actually to mention this and kudos should be given. Inevitably it does stray a little into the environmental issues associated with such events, but the balance was still on the biography aspect.
Next up is Ice and typically looks at the poles and glaciation. Explanations of how the ice sheets have shaped our world, not just in our lifetime but through out geological time, are well delivered. The fact that ice ages are nothing new is well told and that their developments have possibly shaped the evolution of man. There was some stunning photography for this episode, flights over the mountain ranges, over glaciers and snow fields, both real, satellite and computer generated. This is good because of the five episodes I felt this was the weakest since it pushed the environmental aspect rather too much. Oh its devastating to see the graphic images of how dramatically the ice sheets are shrinking and how the world will be effected as they do, but this strayed a little too far from the Earth's story for me.
The next episode is Oceans and follows directly on from the preceding episodes. Tides driven by the moon and waves driven by the wind are discussed and how the ocean is such a good conveyer of energy, it's why tsunamis are of such devastation as the energy builds up and is transferred so quickly once the water runs out. Of particular interest is the ocean currents both on the surface and those deep in the depths and how they affect the land masses. We're all familiar with the Gulf stream and how it keeps western Europe particularly warm, but there are sub-currents that flow around the globe connecting all the oceans. One interesting fact is that these currents are driven by the polar caps and the cold water sinking; cue more environmental catastrophe should the ice caps melt. However this is well balanced with such events occurring during the geological record. Details of how shifing earth movements have closed oceans and opened new ones, film of how the Mediterranean sea has dried up many times is graphically illustrated by walking through the stunning salt mines. Of all the episodes so far this one contained the most information that I did not already know, including the fact that the moon is actually moving away from the Earth and will eventually leave us completely.
Finally Rare Planet, which is a kind of summing up of all the episodes so far. But more than that Stewart goes on to explain which single event he believes was the Earth's most fortunate for the production of how we know it today. He describes the collision of Earth's twin, an event that had the dual effect of substantially increasing the worlds mass, i.e. increasing its gravity enabling it to hold onto its fledgling atmosphere and producing the moon that drives the tides. Whether or not you subscribe to Earth's twin, there are strong theories to suggest that the moon was indeed formed from a collision and that that collision did have the effects Stewart talks about. Indeed the Earth's history is full of such coincidences; meteoric collisions altering the course of evolution, its position from the sun allowing free water to exist, the type of sun it orbits burning at the right heat for the right length of time and even the solar system itself with Jupiter guarding the outer orbits. All these things have combined to enable life on Earth to develop and it's a pretty amazing thing, one might also think divine. But then given enough time is anything possible? Given enough time the Earth would erode itself away, if it did not keep producing more land.
This summation episode really brings together everything that has preceded and places the planet as its rightful position as a unique (so far as we know) entity; a living breathing system that will out live us all. Stewarts closing statements should be held in high regard, listened to and understood; for he tells us that we can throw whatever we want at the world, burn it to a crisp, boil the seas, wipe out all life; Earth will return to its natural state with time, it always has and always will; we shouldn't be looking to 'save the planet', it doesn't need it, we need to save ourselves.
This whole set should be applauded, its tells the story of our world and how it came to be in clear and easily identifiable language illustrated by some of the best natural photography I have ever seen. The slight side step into environmental issues is well balanced with the natural world and as a whole makes up to a very engaging and entertaining series. I can wholeheartedly recommend this title.
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