Agence France-Presse: Climate activists gathered on the steps of Sydney’s iconic Opera House Saturday and along the city’s beaches to kick off an international day of protest about global warming. Along the famous sands of Bondi Beach and across the span of the Harbour Bridge protesters gathered with placards bearing the logo 350 to call for a cut in carbon emissions to 350 parts per million (ppm), organisers said. Thousands of people gathered on the steps of the Opera House for an outdoor concert …