Planet Earth

How many trees does it take to produce oxygen for one person? © iStock

How many trees does it take to produce oxygen for one person?

Heavy rains and mudslides devastate Peru during El Nino season (AFP/Getty Images)

Is El Nino shielding us from climate change?

Is atmospheric oxygen declining, and does it matter? © Sony DSC

Is atmospheric oxygen declining, and does it matter?

Should we mine the seabed? © Getty Images

Should we mine the seabed?

Why does wind blow in gusts and not at a steady rate? © Getty Images

Why does wind blow in gusts and not at a steady rate?

How did Earth get its name? © iStock

How did Earth get its name?

What is smog and how can it be prevented? © Getty Images

What is smog and how can it be prevented?

How many man-made gases are destroying the ozone layer? © iStock

How many man-made gases are destroying the ozone layer?

Is The Great Wall of China really visible from space? © Getty Images

Is the Great Wall of China really visible from space?

When will Earth become uninhabitable? © Getty Images

When will Earth become uninhabitable?

Is it possible to harness the power of falling rain? © Getty Images

Is it possible to harness the power of falling rain?

What makes icebergs flip over? © iStock

What makes icebergs flip over?

How much salt is there in the Dead Sea? © Getty Images

How much salt is there in the Dead Sea?

Climate change: is it too late for Pingu and pals? © Dee Boersma/U of Washington

Climate change: is it too late for Pingu and pals?

How long can a structure last in a desert before being swamped by sand? © iStock

How long can a structure last in a desert before being swamped by sand?