In October 2003, a little-known think tank in the Department of Defense quietly released a report warning that climate change could happen so suddenly it could pose a major threat to our country's national security. Why was the Pentagon worried about abrupt climate change? Because new evidence from Greenland showed it had happened before. 

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.

In this activity, students examine the effects of hurricanes on sea surface temperature using NASA data. They examine authentic sea surface temperature data to explore how hurricanes extract heat energy from the ocean surface.

This hands-on activity explores the driving forces behind global thermohaline circulation.

This NASA animation depicts thermohaline circulation in the ocean and how it relates to salinity and water density. It illustrates the sinking of water in the cold, dense ocean near Iceland and Greenland. The surface of the ocean then fades away and the animation pulls back to show the global thermohaline circulation system.

This short video from NASA discusses the role that salinity plays in Earth's climate and ocean circulation, focusing on the observations of the Aquarius satellite.

This map shows the pattern of thermohaline circulation. This collection of currents is responsible for the large-scale exchange of water masses in the ocean, including providing oxygen to the deep ocean. The entire circulation pattern takes ~2000 years.

This video segment uses data-based visual NOAA representations to trace the path of surface ocean currents around the globe and explore their role in creating climate zones. Ocean surface currents have a major impact on regional climate around the world, bringing coastal fog to San Francisco and comfortable temperatures to the British Isles.

This Changing Planet video documents scientists' concerns regarding how melting Arctic sea ice will increase the amount of fresh water in the Beaufort Gyre, which could spill out into the Atlantic and cause major climate shifts in North America and Western Europe. The video includes interviews with scientists and a look at the basics of how scientists measure salinity in the ocean and how ocean circulation works in the Arctic.