b. Environmental observations are the foundation for understanding the climate system. From the bottom of the ocean to the surface of the Sun, instruments on weather stations, buoys, satellites, and other platforms collect climate data. To learn about past climates, scientists use natural records, such as tree rings, ice cores, and sedimentary layers. Historical observations, such as native knowledge and personal journals, also document past climate change.

In this video, students learn how scientific surveys of wildlife are performed at a site in Yosemite, California, and how these surveys are being used -- in conjunction with studies from the early 1900s -- to provide evidence that animal populations in Yosemite have shifted over time in response to rising temperatures.

In this video segment, adapted from Navajo Technical College, two Navajo Elders speak about climate change and differences in the environment that they have observed.

This video features the Prairie Heating and CO2 Enrichment Experiment near Cheyenne WY, where scientists expose mixed-grass prairie to higher temperatures and CO2 concentrations to study impacts on the prairie for late in this century.

This video from ClimateCentral looks at the way climate conditions can affect vegetation in the West, and what influence this has on wildfires. Drought and rainfall can have very different wildfire outcomes, depending on vegetation type, extent, and location.

This is an interactive graph that involves records of ice cover in two Wisconsin lakes - Lake Mendota and Lake Monona - from 1855-2010.

A detailed Google Earth tour of glacier change over the last 50 years is given in class as an introduction. Students are then asked to select from a group of glaciers and create their own Google Earth tour exploring key characteristics and evident changes in that glacier.

In this activity students download satellite images displaying land surface temperature, snow cover, and reflected short wave radiation data from the NASA Earth Observation (NEO) Web site. They then explore and animate these images using the free tool ImageJ and utilize the Web-based analysis tools built into NEO to observe, graph, and analyze the relationships among these three variables.

This is a sequence of 5 classroom activities focusing on the El NiÃo climate variability. The activities increase in complexity and student-directedness. The focus of the activities is on accessing and manipulating real data to help students understand El NiÃo as an interaction of Earth systems.

In this exercise learners use statistics (T-test using Excel) to analyze an authentic dataset from Lake Mendota in Madison, WI that spans the last 150 years to explore ice on/ice off dates. In addition, students are asked to investigate the IPCC Likelihoodscale and apply it to their statistical results.

This lesson explores El Nino by looking at sea surface temperature, sea surface height, and wind vectors in order to seek out any correlations there may be among these three variables, using the My NASA Data Live Access Server. The lesson guides the students through data representing the strong El Nino from 1997 to 1998. In this way, students will model the methods of researchers who bring their expertise to study integrated science questions.