One of the winners of the Earthshot climate prize is a UK firm that makes packaging from seaweed.
Notpla created the alternative to plastic.
While they were students at Imperial College London and the Royal College of Art, the firm was founded by two men.
Firms that come up with innovative ideas for the environment are given grants by the Earthshot Prize.
Plastic pollution and manufacturing add to greenhouse gases.
Notpla's first product was an "Ooho" that could hold water, and then a second product was made from seaweed.
Its products include a film made from seaweed and a rigid plastic alternative made from seaweed.
More than a million food boxes have been made for Just Eat.
Notpla was a winner at the Earthshot Prize award ceremony.
The winners of Earthshot prove that we can overcome our planet's greatest challenges, according to the Prince of Wales.
My hope is that the Earthshot legacy will continue to grow, helping our communities and our planet to thrive.
"When we started Notpla eight years ago in our student kitchen, we would have never imagined we'd be here today."
It's not too late to make a difference in the world of plastic waste. There is never a better time to use natural solutions.
Plastic pollution can be seen from the polar sea ice to the deepest part of the ocean.
Plastic can be harmful to marine species.
Microplastics are small pieces that can be broken into and used in food.
seabirds were eating plastic and glitter after they mistook them for fish.
Adult birds were feeding plastic to chick's which could have come from fishing equipment or prey.
Thousands of pieces of plastic were washed up on a remote British island.
China, Japan, and South Africa are some of the countries where litter was found on the south-western coast of Ascension Island.