Buses were diverted away from Elizabeth Street and Park Street because of the march,with some buses delayed by up to 30 minutes andmore than 60 routes affected.
After a series of speeches,the crowd began marching down York Street at 6.40pm,before turning onto Park Street and heading east towards Elizabeth Street and Hyde Park.
NSW Police Inspector Gary Coffey said"it’s a very big crowd",and later told theHeraldthere were an estimated 20,000 people in attendance.
Loading
Chloe Rafferty,one of the organisers,said she was angry about the lack of climate action from all levels of government.
"The state is angry,Sydney is angry,"she said."I have hope that people will see the need to take action into their own hands and disrupt business as usual,we can't let the biggest city in Australia having hazardous air quality become the new normal."
High school student Amy Lamont addressed the thousands of protesters wearing P2 face masks and said:"The reality is these fires will be around all summer."