10.Ice Ages and Global Warming

Ice Ages and Global Warming

The energy of the gulf stream comes from the heat of the sun on the tropical seas of the Gulf of Mexico and the Atlantic Ocean. As it delivers its heat to the north Atlantic it cools and sinks. As the Arctic Ocean warms, the gulfstream will deliver its heat further and further north. It may end up pushingright through the Arctic basin, and out into the Pacific between Alaska andSiberia. It won't stop simply because the deep water current heading southunder the North Atlantic isn't as strong.

Since the end of the ice age the melting glaciers have had a profound effect on the climate. Glaciers in the Himalaya provided water as they melted for a series of civilisations. When the reserves of ice came to an end, the rivers and the irrigation systems dried out and the civilisations collapsed. The climate dried out, the temperatures rose and the fertile land turned to desert. These cradles of civilisation are now desert, not through overgrazing, or overpopulation. Simply because the ice ran out.

Similarly the climate of northern Europe has been moderated by the ice of glaciers that have now nearly gone. As their capacity to absorb the heat ofthe summer sun has melted away, the summer temperature starts to rise.

The Alaskan glaciers have also exerted a cooling effect on the whole ofthe northern hemisphere for the last 10,000 years, but they too are melting, thining, and as the surface of the ice shrinks, their ability to cool the northern summer also shrinks. As the ice disappears, it doesn't effect the northern climate slowly, because a thin layer of ice will cool the climate as effectively as a thick layer of ice. But as holes start to develop in theice cover, and its surface area starts to decrease rapidly, then its abilityto modify the climate also falls rapidly, and the melting of the ice alsoaccelerates.

Global warming is the result of the glaciers disappearing, far more than the result of human activity! The greenhouse effect will exacerbate this warming,but the Arctic is going to warm whatever man decides to do.
This information is copyright Peter Thomson 2001-2004