This video features research conducted at University of Colorado's Institute of Arctic and Alpine Research, which studies isotopes of hydrogen trapped in ice cores to understand climate changes in the past.

This interactive visualization depicts sea surface temperatures (SST) and SST anomalies from 1885 to 2007. Learn all about SST and why SST data are highly valuable to ocean and atmospheric scientists. Understand the difference between what actual SST readings can reveal about local weather conditions and how variations from normalâcalled anomaliesâcan help scientists identify warming and cooling trends and make predictions about the effects of global climate change. Discover the relationships between SST and marine life, sea ice formation, local and global weather events, and sea level.

This short video is an excerpt from the longer video Acid Test: The Global Challenge of Ocean Acidification, produced by the National Resources Defense Council (NRDC). This short version summarizes the science of ocean acidification as well as the social implications.

This is a lab about evidence for past climate change as captured in ice sheets of Greenland and Antarctica. Students investigate climate changes going back thousands of years by graphing and analyzing ice core data from both Greenland and Antarctica. They use information about natural and human-caused changes in the atmosphere to formulate predictions about Earth's climate.

This visualization presents a collection of sea ice data taken over a period of 34 years. Selected data can be animated to show changes in sea ice extent over time. Data is added by the National Snow and Ice Data Center as it becomes available.

This is a series of NASA Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images taken over a 10 year period, 2000-2010, showing the extent of deforestation in the State of Rondonia in western Brazil over that period of time.

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.

“El Niño is Strong!” “No, it’s Moderate!” “But the [insert your favorite ENSO indicator here] is the largest it’s been since the El Niño of 1997-98!”

ENSO blogger Tony Barnston explains why climate forecasters can't get by with just a single indicator for predicting El Niño and La Niña.

How can warming at Earth’s surface have slowed when energy accumulation is growing? The role of our oceans—including ENSO—is key.