Key Terms

Greenhouse Gases – Gases which affect the planet in the same way that a greenhouse affects the plants inside it: by warming them. These gases are released both naturally (e.g. volcanic eruptions or released from the ocean) and by humans (e.g. driving cars, warming buildings and farming). They are increasing in number in the atmosphere as a result of increased human activities.

They sit in the atmosphere like an invisible bubble surrounding the earth. The sun’s energy (and therefore heat) can pass easily into the bubble to hit the earth’s surface, but when it is reflected off the earth’s surface and back into space, much of the energy cannot escape the bubble. The more greenhouse gases, the less of the sun’s energy can escape the earth’s atmosphere and the warmer earth becomes.

Carbon Dioxide or CO2 – Perhaps the most well-known greenhouse gas because of its unnaturally sharp rise over the last century. It contributes to the planet’s warming and is released from natural sources as well as human sources.

Sea Ice Vs Land Ice – Sea ice is frozen ocean water whilst glaciers, ice sheets and ice shelves all form on land. This means that sea ice melting doesn’t necessarily cause sea-level rise, but melting land ice does (as it involves adding more water to the ocean than was there originally). Sea ice also varies greatly depending on the season e.g. in summer there is significantly less (this is natural and not to do with climate change)!

Whilst most of the Arctic is sea ice, without land beneath it, deep down below the Antarctic ice sheet is land, although sea ice does also surround this southern continent.

Arctic vs Antarctic –

Arctic	Antarctic
North Pole	South Pole
Polar bears live here	Penguins live here
Mostly sea ice	Mostly land ice
Some people live here (e.g. Greenland)	Nobody lives here (except scientists on research stations)

Play this game to help learn the differences: https://discoveringantarctica.org.uk/activities/spot_the_difference/activity.php

Ecosystems- Ecosystems are the interaction between plants, animals and their environments e.g. a pond or desert or mountain belt are examples of ecosystems of different sizes.