A climate change protester has been charged over disrupting peak-hour traffic in Adelaide after using a rope to suspend herself from a city bridge.

The 69-year-old woman spent about 90 minutes dangled above North Terrace after abseiling over the Morphett Street bridge on Wednesday morning.

Extinction Rebellion South Australia said her action was to give a "life or death message" to delegates attending the nearby Australian Petroleum Production and Exploration Association conference at the Adelaide Convention Centre.

"No new oil and gas exploration and production, if we want to avert total climate catastrophe and collapse of our natural systems," the group said.

It said traffic on Morphett Street and on North Terrace had been safely diverted.

Once brought down, the woman was charged with obstructing a public place and with disturbing the peace.

Police Commissioner Grant Stevens described the protest as selfish and reckless.

"It was very infuriating to hear what people had to put up with, as a result of this completely selfish protest activity," he told radio FiveAA.

Mr Stevens said he fully supported the right of people to protest.

"But there's a way to do it to get your message across and there's a way to do it and piss people off," he said.

"By all means protest, but do it in a way that doesn't unfairly and disproportionately affect so many innocent people."

Premier Peter Malinauskas said he was also sympathetic to the group's cause, but questioned the value of their actions.

"I don't know who Extinction Rebellion is persuading when they pull stunts like the one they have this morning," he said.

"I think they do the cause they seek to represent, harm."

It was the second day of action at the APPEA event after several activists glued themselves to the pavement outside the conference on Tuesday.

That action was dismissed by federal Resources Minister Madeleine King who said they were "using petrochemicals to glue themselves to the footpath".