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.

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.

This video describes why tropical ice cores are important and provide different information than polar ice cores, why getting them now is important (they are disappearing), and how scientists get them. The work of glaciologist Lonnie Thompson is featured, with a focus on his work collecting cores of ice from high mountain glaciers that contain significant data about past climate change.

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

This video describes the role that dendrochronology plays in understanding climate change, especially changes to high elevation environments at an upper tree line. Dendrochronologists from the Big Sky Institute sample living and dead trees, describe how correlations between trees are made, and explain how tree cores record climate changes.

This video describes the impact of extreme heat on Philadelphia in the summer of 2011 and how the city is adapting to new expectations about its weather. It uses this example to introduce the new national climate normals, released by NOAA's National Climatic Data Center (NCDC) that summer.

This interactive visualization provides a clear, well-documented snapshot of current and projected values of several climate variables for local areas in California. The climate variables include observed and projected temperatures, projected snowpack, areas vulnerable to flooding due to sea level rise, and projected increase in wildfires. The projected values come from expert sources and well-established climate models.

This interactive shows the extent of the killing of lodgepole pine trees in western Canada. The spread of pine beetle throughout British Columbia has devastated the lodgepole pine forests there. This animation shows the spread of the beetle and the increasing numbers of trees affected from 1999-2008 and predicts the spread up until 2015.

This is a collection of five short videos - The Arctic Ice Cap, Sampling the Ice, Arctic Fisheries, Natives Feel Effect and Arctic Energy -- that can be played separately or in sequence. They show how climate change is affecting fishing, native populations and access for the oil and gas industry in the Arctic. The videos include personal reflections by writers Andrew C. Revkin and Simon Romero , scientists and residents about their experience of the impacts of the climate change in the Arctic.

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).