Final answer:
During the last ice age, the climate was marked by low temperatures and low precipitation, creating significant ice sheets over the Northern Hemisphere. This period lasted around 20,000 years, ending about 14,000 years ago. It affected global temperatures and precipitation patterns, leading to environmental challenges for both ecosystems and human populations.
Step-by-step explanation:
The climate during the last ice age was characterized by significantly lower temperatures and often lower precipitation levels. As a result, large ice sheets formed, covering much of the Northern Hemisphere. These conditions lasted for about 20,000 years and ended roughly 14,000 years ago. At the height of the last ice age, approximately 2 kilometers of ice lay over regions such as Boston, extending as far south as New York City. While a time of extensive glaciation, the era was marked by cooler global temperatures with mean annual temperatures dropping significantly, which, in some regions, led to droughts and limited the availability of rain due to decreased evaporation and larger quantities of water trapped in ice.
Diverse environmental factors triggered the Little Ice Age, such as ocean circulation changes, shifts in the earth's orbit, and volcanic eruptions. These caused an advance in mountain glaciers and an overall drop in global temperatures, which had profound effects on agriculture, leading to widespread crop failures and famine. Additionally, the scarce rainfall resulted from more water being locked in ice and less contributing to the water cycle, significantly altering habitats and leading to challenges for populations such as early humans, who needed to migrate to secure essential resources.