India opens two world-leading clean energy projects - the world's biggest solar farm and a chemicals plant using CO2 to make baking powder.

Potentially disruptive volcanic ash clouds cross Northern Europe more frequently than previously thought.

The world's oldest known killer whale, estimated to be 105 years old, is missing and presumed dead, researchers say.

New Year fireworks contributed to high pollution levels in German cities, official figures suggest.

Illegally traded endangered species that escape to form secondary populations offer opportunities for their long-term survival, a study suggests.