Early humans most likely experienced which of the following changes in climate and environment? select all that apply. changes in environment from grassland (savannahs) to tropical forests changes is climate forcing migration to find animals for food change in climate revealing passageways for migration changes in climate altering rivers with droughts or floods changes in environment causing animal habits changes

Which suggests the most critical aspect of the peak oil theory? 1) controversy rages over rumors that the fracking lobby in washington has influenced the statistics. 2) supporters and critics argue endlessly over the rate of extraction and shape of the bell curve. 3) saudi arabia will soon have to begin fracking, leading to protests and further destabilization. 4) a new oil discovery means a fresh peak cycle, making that region the target of aggressors.