Climate and the sun

14 Jul 2010

www.nguno/en-gb/Aktuelt/2008/Less-ice-in-the-Arctic-ocean-6000-7000-years-ago/ is an article that dates back to October 2008 but is interesting as raised beaches on the north coast of Greenland are said to suggest ice cover in the Arctic Ocean was greatly reduced some 6000-7000 years ago (Astrid Lysa, a Norwegian geologist, and colleage Eiliv Larsen of the NGU, Norway). In other words, during the Mid Holocene Warm Period (MHWP), roughly 8000 t0 5000/4500 years ago, much of the ice melted and this allowed humans to settle in the region (not Inuit who followed the ice after 4000 years ago), a finding in keeping with what is known was happening in Siberia and Scandinavia - the tundra zone shrank during the MHWP. Hnece, melting ice in the Arctic is not unprecedented - and neither is it catastrophic. In the MHWP  it was beneficial to humans - and farmers expanded into regions formerly too cold. In northern Greenland humans colonised the region in the MHWP but were forced to migrate when temperatures turned cooler - and ice began to play a bigger role. In contrast, the Inuit, around 4000 years ago, exploited the ice - and had a pro-ice hunting strategy.

At there is an interesting set of visual graphs used to illustrate a brief point. The intensity of the magnetic pole at Hudson By is falling away and at the same time the Siberian extremity is rising. As a result of this the warm saline current that runs alongside Greenland has experienced a temperature rise. The magnetic change also effects cooler currents of water - which in turn play a role in ice formation. In contrast, the ability  of warm surface water to effect the coast of northern Siberia is declining and as a consequence, here the temperatures are falling. At no stages does MA Vukcevic mention C02. Why? It does not play a role in what is happening in the Arctic. C02 makes plants grow - but I suppose there is not a lot of plant life inside the Arctic Circle. Instead, it is the Sun that rules the roost - and its effect on the magnetic field.