No.17 Offset your carbon with Inga alley cropping! Part 1
By Tiiu Miller | Newsletter No. 17 January - February 2010

Have you had a great a holiday? Would you now like to do a bit for the environment and off set your carbon? Several people have donated to Rainforest Saver for that. Rainforest Saver does not offer carbon credits in any official way. But we think it is appropriate for purely voluntary contributions, and here's why, in three parts.

Part 1. How might Inga alley cropping sequester carbon, and points to consider in evaluating a carbon off set scheme.

Part 2. A rough guide to what you might give.

Part 3. Is carbon offsetting good or bad? A personal view (to be published later)

Part 1A. How is Inga alley cropping appropriate for carbon sequestration? 

Slash and burn destruction

The destruction. Photo by FUPNAPIB 2006.                                                               


Remaining intact rainforest, Honduras. Photo by Tiiu Miller © 2009.

The Inga system itself probably sequesters little, if any, carbon directly.  There is the possibility it sequesters some because ploughing is not involved and ploughing releases carbon. Also burning the Inga branches as fuel for cooking is a renewable source of energy that avoids the collection of firewood from forests. That too can cause considerable damage even when the forests are not completely cleared. However none of these possibilities have been researched. Also paying individual small farmers an appropriate amount for carbon sequestration might be too costly to verify even if the appropriate amount could be calculated. And payment might even encourage some who were not doing any burning to start burning so as to claim the money.

However the Inga system has some very important indirect effects.

In a previous newsletter (, after visiting Honduras, Antony Melville wrote:

"A rudimentary calculation suggests that with prunings being used for firewood and the small stuff rotting with the leaves to release methane, the Inga itself is probably only marginally, if at all, more of a carbon sink than the rough grassland it replaces, except in as far as it replaces other fuel and thereby is likely to save some CO2. Its main value for carbon sequestration therefore lies with the displacement of forest destruction by slash and burn. On the basis of Victor Coronado's figure ... a five-year programme of Inga alley cropping would be displacing 20 ha of slash and burn per hectare of Inga."  (My italics).

Mountain top summer 2008

Slash and burn in Honduras summer 2008. Photo by Romy Krueger © 2008.

Increased land clearance May 2009

Increased slash and burn May 2009. (Photo by Tiiu Miller © 2009.

"However many people would value highly the beneficial effect of reducing this pressure on the forests even without formal accreditation and would be happy to support it on that basis. Indeed, there are many doubts about many of the carbon balancing schemes."

 Ethical consumer found most carbon off set schemes seriously lacking. Of the 13 providers they assessed they rated 2 as excellent and 7 as poor. If you want to read about some really ineffective carbon sequestration schemes try

The excellent Ethical Consumer report (May/June 2007) can be downloaded from

They then go on to discuss alternatives to formal offset providers, such as supporting various organisations that are providing schemes that use less carbon, or are educating people or campaigning on the issue. Inga alley cropping would most certainly qualify as a very good scheme on such a basis.

There is wide agreement that if we don't save the forests we don't save the climate either, to say nothing of all the other benefits of forests

 Overall it is generally estimated that about 18 - 20% of our carbon emissions come from the destruction of forests. But only a proportion of this, maybe now only 40% (, p.34 - 35), is from slash and burn, giving about 8% of our total emissions. But that is not an insignificant figure. And it is just for a destructive process that keeps the farmers in poverty and may eventually cease to support them at all. This is the lowest estimate I have seen, but it still exceeds the likely contribution of aviation! 

Causes of deforestation in the Amazon chart

Diagram of the relative importance of different causes for deforestation in the Amazon. (Used with the kind permission of

Previous estimates have put the contribution of slash and burn at 50 - 60%, of emissions from forest destruction, giving an overall figure of about 13% of human emission rather than 8% as above. At present that proportion is decreasing while the proportion from large-scale operations is increasing. Also the proportion of urban to rural populations is increasing, all of which may suggest that the effects of slash and burn may be diminishing. See for an excellent up to date account and discussion of this. They make the case that we need to take account of such changes and that this greater involvement of larger businesses is an opportunity to help to preserve the forests by consumer pressure for responsible management, particularly as many of these businesses want to export to the more environmentally aware consumers of Europe and the USA.

But although the proportion of urban to rural dwellers is increasing, at least in the three graphs given in the Mongabay article cited above (for Brazil, Indonesia and the Democratic Republic of Congo) this proportional increase is more by the increase of the urban population than a decrease of the rural. Slash and burn still remains a significant destructive and wasteful force that degrades the land, destroys biodiversity, but does not alleviate poverty.

Moreover as populations increase, and the number of poor slum dwellers increases, there may well be more migration to the forests for slash and burn farming in the future as food in the cities becomes scarcer and dearer. Not only can Inga alley cropping feed the farmer and his family but it can enable him to produce cash crops to feed the city dweller too. Farmer cooperatives would facilitate this, with benefits all round.

Cash crop of pineapples grown in Inga alley

Cash crop of pineapples grown in Inga alley. Photo by FUPNAPIB © 2006.

Vanilla pods grown in Inga alley

Vanilla pods grown in Inga alley. Photo by FUPNAPIB © 2006.

Unless we provide the slash and burn farmers with an alternative, no one is going to prevent them cutting down the rainforest. If they migrate to city slums, frequently there is no work for them and life is really dire. In theory we could stop illegal logging, stop the use of palm oil as fuel, and reduce our meat consumption. There are campaigns on all these issues. But I have not come across a campaign against slash and burn farmers. It would be hard to implement with millions of individual small farmers, and moreover who is going to stop starving farmers from feeding their families the only way they know? You can't tell starving people to go away and die. Yet in Inga alley cropping we have an effective alternative that both benefits the farmers and saves the rainforest. Giving them such an alternative is the only way forward.

The staple crop of maize

The staple crop of maize grows well in the Inga alley. Photo by FUPNAPIB © 2006.

Part 1B. Some points to consider when evaluating a carbon offset scheme:

  1. Carbon emitted to-day needs to be offset now or in the near future. So if a tree takes 50 years to have absorbed the carbon you emitted planting such trees would only be a good option if you paid for so many that their growth in the first few years covered your emissions, and what happened thereafter was a bonus.
  2. Whatever is done should be something that would not have happened anyway even if the carbon offset money had not been paid.
  3. Whereas one could look for a means of simply sequestering the carbon surely it is better if the scheme has extra benefits.
  4. There needs to be monitoring and feedback so that you can find out how your money has been spent, and be satisfied it has been spent efficiently, as intended, without excessive overheads.
  5. The promised activities should really result in reduced carbon emissions or increased absorption, and actually take place and not be undone. A forest that burns down isn't much use. Some off setters allow for such setbacks by for example planting extra trees.

How do Inga alley cropping and Rainforest Saver measure up to these points?

  1. It takes only two to three years to establish an Inga alley plantation, and thereafter it functions year after year. That is acceptable.
  2. The work of Rainforest Saver is totally dependent on donations. The more money we get the more we can and will do, so we score 100% on this one.
  3. Again, 100%. The farmers and their families benefit greatly over and above any forest saved.
  4. Rainforest Saver takes monitoring and feedback very seriously. Our partners fully understand this and supply substantial feedback, accounts and so on.
  5. We are supporting practical, functioning projects that will expand when more money becomes available. Inga alley cropping is a proven technology that provides sustainable living for years. We believe that eventually as produce is repeatedly removed from the system inexpensive farmyard manure can be added to replace nutrients if needed so that the plot can be farmed indefinitely.

So we recommend Rainforest Saver as an appropriate recipient for carbon offsets. We will discuss possible amounts in the next part. However, as this is purely voluntary you are in any case free to give whatever you deem right, or whatever you can afford. All donations, great and small, will be very gratefully received.

Please donate either through PayPal at the top right  of this site, or send a cheque. SeeProjects>Support Us for further information.