The UN explains: "Significant strides have been made in increasing life expectancy and reducing some of the common killers responsible for child and maternal mortality.

Major progress has also been made on increasing access to clean water and sanitation, reducing malaria, tuberculosis, polio and the spread of HIV/AIDS.

However, many more efforts are needed to control a wide range of diseases and address many different persistent and emerging health issues."

The UN explains: "Clean water is a basic human need, and one that should be easily accessible to all. There is sufficient fresh water on the planet to achieve this. However, due to poor infrastructure, investment and planning, every year millions of people — most of them children — die from diseases associated with inadequate water supply, sanitation and hygiene."

The UN explains: "Our oceans — their temperature, circulation, chemistry, and ecosystems — play a fundamental role in making Earth habitable.

Our rainwater, drinking water, weather, climate, coastlines, much of our food, and even the oxygen in the air we breathe, are all ultimately provided and regulated by the sea. Throughout history, oceans and seas have been vital conduits for trade and transportation. Careful management of this essential global resource is a key feature of a sustainable future."