National Geographic News

June 11, 2012, 9am PDT
With cities across the country seeking to find innovative and economical solutions to problems caused by combined sewer systems, could Philly's popular Green City, Clean Waters program be a model worth copying?
National Geographic News
April 6, 2007, 5am PDT
<p>To raise awareness of global warming, a massive sea level change was staged in the online virtual reality world "Second Life" that flooded areas such as London and Tokyo -- similar to what scientists predict could occur within this century.</p>
National Geographic News