b. Climate plays an important role in the global distribution of freshwater resources. Changing precipitation patterns and temperature conditions will alter the distribution and availability of freshwater resources, reducing reliable access to water for many people and their crops. Winter snowpack and mountain glaciers that provide water for human use are declining as a result of global warming.

This activity engages learners in examining data pertaining to the disappearing glaciers in Glacier National Park. After calculating percentage change of the number of glaciers from 1850 (150) to 1968 (50) and 2009 (26), students move on to the main glacier-monitoring content of the module--area vs. time data for the Grinnell Glacier, one of 26 glaciers that remain in the park.

This video examines what will happen to crops as Earth's temperature rises and soils dry out because of changing climate. Students learn that a loss of soil moisture causes stress to plants, leading to crop withering. Since humans and animals depend directly or indirectly on plants for food, many societal problems can be expected to arise due to the impact of climate warming on crops and the societies that depend on them.