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. Using a second-order polynomial (quadratic function) fitted to the data, they extrapolate to estimate when there will be no Grinnell Glacier remaining (illustrating the relevance of the question mark in the title of the module).

In this activity, students investigate how scientists monitor changes in Earth's glaciers, ice caps, and ice sheets. The activity is linked to 2009 PBS Nova program entitled Extreme Ice.

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 key figure is on page 11 of the PDF found at the link above (it is listed as page 3 in the document). The link is to the 2007 Intergovernmental Panel on Climate Change (IPCC) synthesis report. This image shows changes in global average surface temperature, global average sea level, and Northern Hemisphere snow cover from as far back as 1850.

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 animation depicts global surface warming as simulated by NCAR's Community Climate System Model (CCSM) Version 3. It shows the temperature anomalies relative to the end of the 19th century, both over the entire globe and as a global average. The model shows the temporary cooling effects during 5 major volcanic eruptions and estimates future temperature trends based on different amounts of greenhouse gas emissions.

This static graph of changes in CO2 concentrations goes back 400,000 years, showing the dramatic spike in recent years.

This visualization is a collection of maps, by continent, that project the impact on coastlines of a 216-foot rise in sea level, which is assumed to be the result of melting all the land ice on Earth.

This video features residents of Shishmaref, Alaska, plus environmental journalist Elizabeth Kolbert and scientist John Holdren, exploring the human impacts of global climate change.

This short video describes how the compression of Antarctic snow into ice captures air from past atmospheres. It shows how ice cores are drilled from the Antarctic ice and prepared for shipment and subsequent analysis.