Results

As noted by Diamond (2005) the Inca civilization was capable of reforms towards sustainability, but the most important thing is the short span of time in which the diversity of maize was introduced and the highland environment became rehabilitated.

According to Tapia (1996, pp.18-19) solar radiation, as the main source of energy for autotrophic life forms, should be considered in the context of the geographic latitude. The combination of radiation and photoperiod affects the possible adaptation and productivity of different species and varieties of crops. The alimentary base of the Urnfield culture, according to the diagnosis of archeological site at Stillfried (48 ° 24'N, 16 ° 50'E, altitude: 144 meters s.n.m), was ‘’Triticum dicococum’’ (Emmer) and ‘’Triticum monococcum’’ (Einkorn) as primitive forms of modern cereals developed at the Mesopotamian Vavilov Centers, together with ‘’lens culinaris’’ as legumes (lentils) and ‘’Vicia faba’’ (domesticated beans).

The alimentary base was, in brief words, on the level of incipient agriculture that requires additional hunting and gathering activities to provide a sufficient diet for the Urnfield people (Kohler-Schneider 2001).

In contrast to, the Andean civilizations have developed a mature agriculture from the horizon Chavin or even more earlier at Caral – Supé (at the times when the pyramids were built).

The El Niño phenomena around 1000 A.D. along with the collapse of the Middle Horizon polities (Wari and Tiwanaku) marks the beginnings of the Medieval warm period (Plachetka / Munoz 2007).

The damage to the forests of the Amazon as a global repository of the circuits of coal has left no signal at the proxies indicating the amount of carbondioxido in the atmosphere (Doney, Schimel, 2007, p.14), as then the oceans could store that, winemaking in Scandinavia during the same time and the population of Greenland require concise local studies.