This is the first of nine lessons in the "Visualizing and Understanding the Science of Climate Change" website. This lesson is an introduction to Earth's climate and covers key principles regarding Earth's unique climate, atmosphere, and regional and temporal climate differences.

In this activity, students compare carbon dioxide (CO2) data from Mauna Loa Observatory, Barrow (Alaska), and the South Pole over the past 40 years to help them better understand what controls atmospheric carbon dioxide. This activity makes extensive use of Excel.

Students examine data from Mauna Loa to learn about CO2 in the atmosphere. The students also examine how atmospheric CO2 changes through the seasonal cycle, by location on Earth, and over about 40 years and more specifically over 15 years. Students graph data in both the Northern and Southern Hemisphere and draw conclusions about hemispherical differences in CO2 release and uptake.

In this activity for undergraduate students, learners build a highly simplified computer model of thermohaline circulation (THC) in the North Atlantic Ocean and conduct a set of simulation experiments to understand the complex dynamics inherent in this simple model.

This is a classroom activity about the forcing mechanisms for the most recent cold period: the Little Ice Age (1350-1850). Students receive data about tree ring records, solar activity, and volcanic eruptions during this time period. By comparing and contrasting time intervals when tree growth was at a minimum, solar activity was low, and major volcanic eruptions occurred, they draw conclusions about possible natural causes of climate change and identify factors that may indicate climate change.

This activity focuses on reconstructing the Paleocene-Eocene Thermal Maximum (PETM) as an example of a relatively abrupt global warming period. Students access Integrated Ocean Drilling Program (IODP) sediment core data with Virtual Ocean software in order to display relevant marine sediments and their biostratigraphy.

In this activity, students learn about the tools and methods paleoclimatologists use to reconstruct past climates. In constructing sediment cores themselves, students will achieve a very good understanding of the sedimentological interpretation of past climates that scientists can draw from cores.

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 explore recent changes in the Arctic's climate that have been observed and documented by indigenous Arctic residents. Students watch a video, take notes, and create a concept map. Students also examine and graph historical weather data and indigenous data for an Arctic community. Students explain why natives are critical observers.

In this activity, students develop an understanding of the relationship between natural phenomena, weather, and climate change: the study known as phenology. In addition, they learn how cultural events are tied to the timing of seasonal events. Students brainstorm annual natural phenomena that are tied to seasonal weather changes. Next, they receive information regarding the Japanese springtime festival of Hanami, celebrating the appearance of cherry blossoms. Students plot and interpret average bloom date data from over the past 1100 years.