Protesters urge caution over St Ives climate trial amid chemical plans for bay

Campaigners worry about scheme's impact on marine ecosystem but Planetary Technologies says concerns misplaced

Planetary can stick it up their waste pipe," read one of the many waspish placards at the north Cornwall beach where more than 300 protesters gathered on Sunday.

They came to Gwithian beach to object to a proposed carbon dioxide removal scheme by the Canadian company Planetary Technologies - winner of a $1m XPrize for climate change solutions in 2022 - which wants to add magnesium hydroxide to the wastewater pipe at Hayle that stretches out to sea.