Offsets: What does that actually mean?

Literally to “offset” means to counter the effect of one ‘thing’ to another.
In terms of the environment it generally refers to the concept of determining an unavoidable impact someone is having and helping and equal and opposite impact occur.
Example: You cut down a tree, you plant another.

The key word from earlier was unavoidable: using offsets alone is not an effective climate mitigation strategy for a number of reasons:

• Not all offsets are created equal.
  If one species is suffering deforestation, helping a different species does nothing for the one with the original problems.
• It kicks the idea of reduction down the road.
  The real solution to long term climate mitigation is to reduce reliance on pollution sources; whether it be energy types or lifestyle choices, buying the way out of the immediate problem does nothing for the underlying problem.
• There’s no guarantee they will work: If you plant a tree to offset a large emission, your assuming the tree will reach its maximum level of offset before it gets destroyed.

There are many different offset programs and strategies ranging from individual actions to paying others to emit less. Carbon Offset Guide is a good way to really dig deeper into this topic.

Although Offsets aren’t long term solutions to climate and environmental issues, the right ones do add value to the ecosystem.