Cookstoves that need a third of the charcoal

We helped distribute 1,500 efficient cookstoves around two of our Madagascar sites. Each one cuts a household's charcoal use by roughly two-thirds, which sounds like a small domestic detail and is in fact one of the more useful things we do for the forest here.

Charcoal is the main reason the forest gets cut in this part of the country. Trees are felled, burned down to charcoal in earth kilns and sold, because charcoal is what people cook on and there is steady money in it. The pressure on the forest edge is, at bottom, the pressure of every cooking fire for miles.

You cannot ask a family to stop cooking. So the useful move is not a ban, it is to make each meal need less fuel. The improved stoves are simple metal-and-clay designs that burn hotter, hold the heat and waste far less than the open three-stone fire they replace.

The household saves money too, which is what makes the stoves spread on their own once enough neighbours have one. A family buying less charcoal each month notices, and a stove that pays for itself does not need us to keep pushing it.

We are clear that this is not a glamorous intervention and that it does not plant a single tree. It is the opposite of a planting day, invisible work that produces no photograph of a green hillside.

But a forest with less demand chewing at its edge has a chance to grow back faster than it is taken. Every stove that halves a household's charcoal need is, in effect, a stand of trees left standing, and that arithmetic adds up faster than planting alone ever could.