Today’s global warming activists are gathering in the middle of the Melbourne CBD this morning, outside BHP’s city office on Collins Street.

It’s being touted as a ‘dress rehearsal’ for their plans to blockade the International Mining and Resources Conference (IMARC) in late October.

The mining industry has copped heavy criticism from around the world as one of the biggest contributors to global warming.

Later today there will be a rave in Carlton Gardens at 5pm.