Trees sequester carbon, and then store it – releasing oxygen and water in the mean time – until they are cut down, blown down, burned down, or die, start to rot and eventually fall down.
But that famous diagram is misleading. It suggests there’s lots of atmosphere to hold all that CO2 (too much, some say, for 400 ppm to be a problem).
(Piers Sellers was Patron of The Priestley International Centre for Climate, with whom UBoC shares a boss and an office).
Also, this happened:
Nearly half gone – and mostly up in smoke.
But not all of a tree is carbon:
Hmm, only 33% of 25%?
Yes, but it’s still worth using trees to soak up carbon dioxide, so many ‘Offsetting’ schemes have been created – and note that capital ‘O’.
(Basically, you pay someone else to deal with your emissions, and they give you a credit note to say you’ve done so, which you can then show to your supporters and/or any relevant authorities).
Pic nicked from Emerson Consulting Nigeria Ltd – with thanks
But here’s the important bit: Not all tree planting counts as ‘Offsetting.’ To qualify, it MUST be done right:
But if you don’t need to be 100% sure that your trees will capture a certified quantity of carbon, you can always just ‘plant and hope.’
You’ll get more bark for your buck that way, but it’s best to only plant in projects that we or someone else has checked and approved as having trees that stand a decent chance of surviving, while also delivering other benefits such as food, water, education, cash for farmers, research etc.
You see, it’s complicated.
(NB: All numbers from here on down are very general – VERY general. We’re just trying to give you some ball-park ideas, ok? There are major variations in all directions, to all figures, according to multiple conditions, various factors and lots of other stuff. So, please, don’t quote us)!
The tree/carbon ratio will vary enormously according to the tree species, where it’s growing, who’s looking after it, and how well, etc.
But generally, tropical tress work MUCH harder for the climate than trees do here in the UK, for example – though all trees do have value. In fact all greenery does when it comes to fixing carbon dioxide, and therefore climate change.
However, trees are easy to count, so we do tend to concentrate on them, and at UBoC we focus on tropical trees for their climate value, and UK trees because our UK supporters often want to plant locally.
How long the tree grows for, and then survives for, for is also critical:
As is what we do with the wood when it’s cut down, blown down or dies naturally.
If it’s burned down then all the carbon is released immediately. Which is a fail. Obviously.
So. One tonne of Carbon = 0.27 tonnes of CO2e.
OK. How many trees is that, then?
Well, it could in theory be just one mature tree, but we don’t want to have to wait for our trees to mature before we can start counting them as carbon. And we also have to expect some losses, even if we put safeguards in place – as we always do.
OK – so let’s take an average of 7 trees for one tonne.
How many do we each need to plant?
(More rounded-up general, average, guesstimate numbers, here ok?)
50 trees a year?
So I just pay some money (anything from £10 to £400 for 50 trees depending on who you pay, in case you’re wondering) and just carry on as before with clear conscience?
Err, actually, NO!
Back to the carbon page and those links.