Explainer: How much carbon can the world's forests absorb?

You are walking through the bush when you see an enormous tree trunk, tens of metres long, lying across the forest floor. Imagine you and several dozen friends lifting it by hand. Now you've literally grasped the significance ...

Why Tehran is sinking dangerously

Iran has a water problem. The reserves in many groundwater basins there have been severely depleted. For the last 40 years, the country has invested a lot in the agricultural sector, and has been striving to be independent ...

Landsat 7 satellite shows tsunami effects in Sendai, Japan

Before and after images from the Landsat 7 satellite show the after effects of the tsunami that followed the 9.0 earthquake off of Japan's east coast last weekend. A side-by-side comparison reveals inland areas inundated ...

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