'In 30 years, there will be more plastic in the ocean than fish.'

In a short video, one of the top stars of our time covers her head with a plastic bag and says: "Just try this bag on for 10 seconds and see how it suffocates you."

"In 30 years, there will be more plastic in the ocean than fish," she adds. "I urge everyone to ban single use plastic bags."

"I'm joining #RallyForRivers and the United Nations in the fight against plastic pollution and I urge you all to do the same."

Watch what she says, folks!