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 video documents the impact of the 2011 drought on the water supply of two Texas towns. It discusses how the higher temperatures have increased the evaporation from open reservoirs, resulting in a drop in their water levels. The use of water in fighting wildfires has also contributed to this drawdown. While some jurisdictions have been able to develop pipelines to other sources, others have had to resort to trucking water in.

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 poster, viewable online, highlights some of the impacts of a global-average temperature rise of 2 degrees C above the pre-industrial age climate.

This is an interactive map of California and the Sierra Nevada mountains, showing projected variations in water stored in snowpack, from 1950 to 2090, assuming low or high emission scenarios over that period of time. Interactive can be adjusted to show different months of the year and various climate models, graphed by site.

This visualization, from the US Geological Survey, provides a simple schematic of the various pathways that water can take as it cycles through ocean, lakes, atmosphere, surface and ground.