Cryosphere Today
One of today’s hottest websites when it comes to global warming is The Cryosphere Today, produced by the Polar Research Group in the Department of Atmospheric Sciences. Devoted to conveying the ever-changing state of polar ice caps, the site includes daily ice concentrations dating back 30 years, charts to show how ice coverage deviates from normal, ice melt animations, and more (even a mobile Web application).
Drawing data from the National Center for Environmental Prediction, the site has become a well-known reference in global warming debates. Whatever your stand, the latest data is there.