This photo shows the 'The Executive Towers' group of skyscrapers under simultaneous construction in Dubai, United Arab Emirates, on March 29, 2007. The Emirate's government's decision to move from an oil-based economy to focus on tourism industry triggered a real-estate development boom that has been going since 2004.
Vanishing? An iceberg that broke from the Jacobshavn glacier floated in the water off Greenland. The berg illustrates how fast the glacial ice is melting in the Arctic and the potential for rising sea levels.
The global credit crunch and falling oil prices are taking a toll on the superrich Gulf emirate as developers mothball high-profile projects and lay off workers.
Architects around the world are erecting skyscrapers that use a hollow concrete core surrounded by bomb-resistant glass and other security innovations.