Thirteen people have been arrested after environmental group Greenpeace called on Prime Minister Scott Morrison to "declare a climate emergency" by protesting on the Sydney Harbour Bridge on Tuesday morning.

Three abseiling protesters could be seen dangling from the bridge between 6am and 9am, holding small banners that read "100% renewables" and "make coal history".

Greenpeace protesters hang off the Sydney Harbour Bridge on Tuesday morning. Credit:Nick Moir

A Greenpeace spokesperson said the abseilers were "fully stocked up" and had enough provisions in their bags to last at least 24 hours, but they were brought back up by police just after 9am.

Mr Morrison responded to the protest later in the morning while campaigning in Boothby, South Australia.