Carbon offsetting is a process by which organisations and individuals ‘balance’ out their carbon footprints by funding emission reductions elsewhere, which can ‘offset’ their own activities and emissions.
For example, to offset the environmental impact of a flight, you could work out the emissions associated with that journey and purchase a carbon offset which guaranteed an equal emissions reduction elsewhere. Offset types include investments in renewable energy or tree planting and offset projects often take place in developing countries where the money invested provides benefits in the local community.
Offsetting is sometimes seen as controversial, especially if it takes the place of efforts at first reducing emissions through behaviour or operational change. It can also be perceived as an ‘easy’ way to shift the burden of action away from those who are more affluent.