Green Left Weekly: More than 175 different climate change actions took place across Australia on October 24. The protests were part of the 350.org international day of climate action. Leading climate scientists say the concentration of atmospheric carbon dioxide must be drawn down below 350 parts per million to ensure a safe climate. But today, it has reached about 390ppm. It rises by 2ppm each year. In Sydney, Brianna Pike reported that 1500 people gathered at the Sydney Opera House and heard …