Past climate changes and human adaptation

Abstract

Climate is the planetary response of the atmospheric circulation to changes in its composition, the solar system configuration, Earth’s rotation, and the distribution of the oceans and continents. As a result, it is continuously evolving, expressed at a global scale by subsiding and uplifting convection cells. These changes have long been recognized and documented in geologic objects of all ages. There are climate signals in many rocks, different geologic features, fossil fragments and imprints, prehistoric remains, and historical reports that can be analyzed and interpreted in order to learn more about past climate changes. Lessons from the past support the view that change is the rule, not the exception, as evidenced by strongly contrasting and chaotic extremes, defined by the whole ensemble of extra-planetary, external, and internal geodynamic controls.