No water, no life.
The oceans produce 70% of the Earth's oxygen, but every day we find thousands of tonnes of plastic waste in them. It takes about 500 years for an ordinary plastic bottle to decompose. The technologies of the modern world allow only 1/3 of the ocean to be cleaned of plastic. Twice as much pollution remains deep at the bottom. As they break down into microplastics, they exhibit poisonous effects on the water, threatening the entire ecosystem. If we do not act today, there will be no clean water or oxygen left on earth, and without these, humanity will not survive.
