Weather is the day-to-day conditions of the atmosphere in a particular place. Climate is the average weather conditions of a place taken over a long period of time, typically 30 years.

Low pressure systems called depressions and high pressure systems called anticyclones can bring extreme weather events to many regions of the world, including the UK.

A variety of ecosystems are spread across the world, each with distinctive interacting characteristics and components. They range from small ecosystems such as a freshwater pond, to global ecosystems such as deserts.