Our Changing World for Thursday 20 February 2014

9:34 PM.Anthony Lealand from Firework Professionals explains the chemistry and physics of fireworks, how they are manufactured, and demonstrates some sounds Read more Audio

9:20 PM.Management of freshwater, including biodiversity on the region's many rivers, are among the issues facing Environment Canterbury's Commissioners. Read more Audio

9:06 PM.The Ashley-Rakahuri Rivercare group is a community effort to look after breeding birds on a North Canterbury braided river. Read more Audio