In the comments to the post on SAAB’s efforts to go green Lisa asks:

Why is tree-based carbon offsets not preferred? Wouldn’t they be more beneficial because they offer more than just carbon offsets such as helping with soil errosion, habitat, etc.

That’s a good question Lisa! I should have put a bit more detail in the post - but as this is something that’s probably of more general interest, I thought I’d post a response here…

Planting trees is a type of carbon capture and storage (sequestration in technical terms). We definitely need to plant more of them for the many benefits they provide!

Our What is offsetting? guide explains the issue this way:

Though in principle [tree-planting for sequestration] is a good idea, some offsets programs have the double-advantage of investing in important new technologies which deliver clean energy, thereby avoiding greenhouse gas emissions at the source - something that tree-planting programs can’t do.

So, in essence, the issue is that planting trees does not reduce the amount of CO2 being emitted into the atmosphere in the first place. This is the reason we’re not too keen on tree-based offsets.

The guide goes on to say:

To make the most of your investment, we recommend programs that comply with the CDM Gold Standard for carbon credits. Be sure to ask your offsets provider where your money goes - specifically if the projects they invest in are accredited to this standard. That way you can be sure that the fees you pay are being used to create a real reduction in carbon emissions.

The CDM carbon credits are audited to ensure that the amount of CO2 you are offsetting has been effectively removed from being emitted into the atmosphere. WWF played an active role in establishing the CDM Gold Standard, so it’s probably little surprise we recommend it

I hope that answers your question Lisa.