While epidemic disease was a leading factor of the population decline of the American indigenous peoples after 1492, there were other contributing factors, all of them related to European contact and colonization. One of these factors was warfare.
They use Economics to Explain.
The correct answer is climate!
Weather is the current state of the atmosphere (cold or warm for example) and global warming is the general trend for the average temperature to increase globally - but it's a specific weather-related phenomenon, not the statement of average historic temperature.
<span>dendrochronology is a method of discovering past weather by the state of tree rings</span>