Signals of Change

Exploring the connections between people, the environment and a changing world.

What is Particle Pollution?

Particle pollution or particulate matter (PM) are mixtures of solid particles or liquid droplets in the air. Some, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. These tiny particles…

Solar energy: harvesting desert sunshine

  Foreseing a future reduction of fossil fuels availability, a German company intends to harvest sunshine from the empty deserts of North Africa and the Middle East using solar energy technology. It aims at using it to produce clean power for the region and…