Ecoclimax

Worldwide, 884 million people have inadequate access to clean water and more than 2.6 billion people do not have basic sanitation. Each year, around two million people die as a result of contaminated water, and most of these are children. This raises the following question: How can we make it clear to people as to why and how they should use water sparingly? 1st Winner: Pawel Dadok - Poland.

More and more people are turning from grocery stores and utility companies in favor of their own back yard. The idea of becoming self-sufficient is an alluring one, but exactly how much land would you need? Assuming a family of four, here are the land requirements to sustain yourself for one year.

Physicist Geoffrey West has found that simple, mathematical laws govern the properties of cities -- that wealth, crime rate, walking speed and many other aspects of a city can be deduced from a single number: the city's population. In this mind-bending talk from TEDGlobal he shows how it works and how similar laws hold for organisms and corporations.

A Solar Innovation Story.

Winds battering southern Australia over the last 24 hours have been so strong that spray from waterfalls south of Sydney has billowed up into the air. Nearly a month's worth of rain has fallen on the city in 24 hours, and wind speeds have reached 120km/h. The extreme weather has meant a rough ride on the city's ferries, and a high surf warning has been issued with waves expected to reach 5m.