This well-designed experiment compares CO2 impacts on salt water and fresh water. In a short demonstration, students examine how distilled water (i.e., pure water without any dissolved ions or compounds) and seawater are affected differently by increasing carbon dioxide in the air.
This is a short NASA video on the water cycle. The video shows the importance of the water cycle to nearly every natural process on Earth and illustrates how tightly coupled the water cycle is to climate.
This activity covers the role that the oceans may play in climate change and how climate change may affect the oceans. It is lesson 8 in a nine-lesson module Visualizing and Understanding the Science of Climate Change.