A measure of how much heat a greenhouse gas traps in the atmosphere (called ‘radiative forcing’) over certain time periods.  Governments have agreed to use this measure to add up the impact of emissions of different gases and how they contribute to global warming.

This is a change in long-term weather patterns due to natural forces, or human activity, or both.

A carbon sink is a natural or artificial reservoir like plants, peat bogs or oceans. It soaks up and stores greenhouse gases like carbon dioxide. This process removes greenhouse gas from the air and it keeps our temperatures from getting too high.