You can't carbon offset with trees

By Brian Clegg

Sigh. For reasons I don’t entirely understand, I receive emails from Travel Neutral, a company that specialises, according to its website, in ‘carbon offset and planet-aware holiday deals’ like the one advertised in the image. To be honest, they aren’t my kind of holiday firm, because I don’t consider going on holiday a good enough reason to fly, but out of interest I followed a link to the company they use for offsetting. 

The good news is that they offer a good range of sensible green schemes from tree planting to renewable energy projects. The bad news is that using these for offsetting is mostly greenwash.

The idea of offsetting is that at the moment we all have to do things that generate greenhouse gasses. So you pay a little money to a scheme that will reduce greenhouse emissions, and this will balance out your contribution to climate change. But unless the amount of money you contribute will reduce carbon emissions (or equivalent) by at least the amount you generated before the next time you fly it’s not really offsetting it. To take the example to the extreme, if your offsetting scheme only resulted in a reduction in 100 years time, then it would be totally pointless in terms of dealing with climate change.

While these schemes aren’t quite so long term, the amount you pay will go nowhere near to producing an equivalent reduction in any even vaguely equivalent timescale to the flight. It would take a tree, for example, maybe 30 years to reduce carbon levels by the amount emitted for one passenger on a roundtrip long haul flight – in the region of 2 to 3 tonnes. (That’s more than a typical UK car emits in a whole year, incidentally.) And most of the benefit would come after the first 10 to 15 years – because saplings don’t take in a lot of CO₂.

I need to reiterate that this does not mean that tree planting and renewable energy projects are bad things. Far from it. We need far more trees and far more green energy production. By all means support them. But it’s magic thinking to believe that by putting a little money into these projects you can wipe the slate clean for your carbon-chugging flights. It won’t.

This has been a Green Heretic production.

See all of Brian's online articles or subscribe to a weekly digest for free here

Now Appearing is the blog of science writer Brian Clegg (www.brianclegg.net), author of Inflight Science, Before the Big Bang and The God Effect.