Sometimes, a picture truly is worth a thousand words. Last month, the United Nations Environment Program (UNEP), in Nairobi, Kenya, announced the winners of its fourth Focus on Your World International Photographic Competition. The contest, which was held in 2004, was open to professional and amateur photographers, young and old alike. Their challenge was to take pictures that illustrate an environmental issue that they consider important.
Some 32,000 photographs were submitted from nearly 170 countries, and the subjects were as diverse as the photographers themselves. According to Klaus Toepfer, UNEP's executive director, the competition "brought into sharp focus the wonder and pain of the modern world."
The entries were judged by a panel of international photographers. Here's a look at some of this year's winning pictures taken by photographers under 21. Toepfer hopes that all of the entries will "trigger action and change in ways that a million speeches and articles could never do."