Outspoken opponent of fracking in the USA, Mark Ruffalo has now turned his focus to the fight against fracking in the UK. 

In this video interview with Friends of the Earth, the Oscar-nominated actor urges David Cameron to abandon the controversial process of fracking once and for all. 

Fracking is the process of drilling into the earth and using a high pressured mixture of water, sand and chemicals to force gas up and out of the ground. 

Ruffalo's strong words come at a pivotal moment, as energy firm Cuadrilla launches an appeal against a local council’s decision to reject its plans for exploratory fracking in Lancashire. 

“Mr. Cameron, you’re making an enormous mistake, it’s a legacy mistake, because there is no fracking that can be done safely,” Ruffalo said. 

He reminded David Cameron of the promises made to the British people and at COP21 where "200 countries from around the world all agree[d] that it's time to leave fossil fuels in the ground."

Ruffalo's message is a powerful call for a “monumental transition to a cleaner safer just world.”