Valuing Guyana’s Forests: Starting with their embedded carbon

McKinsey Report: LCDS       

 

Last week’s column addressed aspects of Guyana’s “high forest cover – low deforestation status”. It was observed that the country’s low deforestation rate signifies a high level for its contribution towards global efforts aimed at 1) reducing carbon emissions 2) containing the build-up of greenhouse gases and, 3) preventing global warming and climate change. Keeping Guyana’s forest cover intact therefore provides environmental services for the global community and, as a small poor developing country, it should be compensated for this contribution.

As readers of my earlier columns would appreciate, the McKinsey Report, (Office of the Presidency, 2008) specifies the “core model” at the heart of Guyana’s Low Carbon Development Strategy (LCDS). Essentially, that model estimates 1) the Economic Value to the Nation (EVN), which is embedded in Guyana’s forests; if land use conversion from forests to non-forest usage was proceeded with expeditiously; and 2) the Economic Value to the World of the Carbon (EVWc), which is presently stored in Guyana’s forests, and which would follow from the country’s avoided deforestation.

In those earlier columns, I had considered the LCDS in some detail; and therefore, I shall not repeat the discussion here. The aspects of it, however, which I am concerned with are the estimates it offers for the carbon stock embedded in Guyana’s forests. These estimates would clearly serve as the basis for estimating its EVWc (cited above), and thus the basis for compensating Guyana for avoided deforestation.

 

Carbon Stock in Guyana’s Forests

Estimations of the carbon stock in Guyana’s forests will be provided in today’s column. Regrettably, however, similar to the observation made last week, the research material which I have come across on this topic, forces me to retreat from my intended reliance on FAO estimates to steer me through the many controversies surrounding data on Guyana’s forests! As I shall elaborate on later, the FAO’s estimates of carbon stock in Guyana’s forests that the McKinsey Report has provided, have since been proven to be unreliable, and have had to be revised upwards subsequently. The material I shall mainly present in today’s column, derives from two studies completed in 2009 by Denis Alder and Marijke van Kuijk for the Guyana Forestry Commission.

 

Carbon Sequestration

To understand these data, readers should bear in mind that, carbon sequestration is a core long–term goal of the global community. It is required in order to mitigate/deter global warming and climate change. Simply put, the focus of carbon sequestration is to slow the accumulation of greenhouse gases on the Planet. And, the leading contributor to these gases is the use of fossil fuels, which result in carbon dioxide emissions into the atmosphere. Indeed, carbon sequestration is considered as: “one of a class of mitigation and adaptation strategies against climate change, and in support of conservation and sustainable use of the forests’ genetic resources”.

As a non-specialist, I have found it convenient for present purposes to reduce the various observations and results found in the two studies cited above to ten basic/essential elements.

Together these reveal that, on average, the above ground biomass found in Guyana’s closed forest yields 362 tonnes per hectare. If tree roots are included, this yields 442 tonnes per hectare.

The carbon generated from this equals 221 tonnes per hectare and the carbon dioxide sequestered equals 810 tonnes equivalent, per hectare. Other ecosystems in Guyana yield lower values, so that the national average for all the land area in Guyana (that is, 209,847 square kilometers) would yield 186 tonnes of carbon per hectare, which when sequestered equals 682 tonnes of carbon dioxide equivalent per hectare.

Further, Guyana’s closed forest areas (estimated at 156,465 square kilometers), contain 3.457 gigatonnes (billions of tonnes) of tree carbon equivalent, and 12.676 gigatonnes of sequestered carbon dioxide. If marsh, swamp, scrub, and savannah are added to this, then Guyana’s total land area sequesters 18.40 gigatonnes.

Schedule 1 presents these data in a concise form for readers’ convenience.

Schedule1: Reported Estimates of Guyana’s Carbon Stock   

 

  1. The average closed forest tree biomass above ground                  =    362 t ha-1
  2. Item 1 above, and including roots of the trees                                =    442 t ha-1
  3. Carbon generated by Item 1                                                              =    221 t ha-1
  4. Item 1, sequestered as carbon dioxide                                             =   810 tCO2-e ha-1
  5. Average for all Guyana’s land area                                                   =    186 tC ha-1
  6. Item 5, sequestered as carbon dioxide                                             =   682 tCO2-e ha-1
  7. Guyana’s closed forest area                                                                =  156,465 km2
  8. Tree carbon in Item 7                                                                          =    3.457 Gt
  9. Item 7, sequestered as carbon dioxide                                              =    12.676 Gt
  10. Item 9, including marsh, swamp, scrub, and savannah                  =    14.309 Gt

 

Source: Author’s construction from Alder and Kuijk, 2009.

The authors who supplied these data were careful to observe that: “these figures are purely for carbon in living trees, bole, roots, and crowns.” Indeed, if one included necromass (deadwood and litter) and soil organic carbon, Guyana’s closed forest areas sequester as much as 15.63 gigatonnes of carbon dioxide (more than Item 10 in the Schedule). And, furthermore, Guyana’s total land area sequesters 18.40 gigatonnes.

 

Conclusion

To wrap up this discussion, it should be recalled also that Guyana’s closed forest makes up about 75 percent of its land area; and, from the data above, 89 percent of its sequestered carbon dioxide!

It is the practice in this field, to avoid giving precise numbers so as to ensure that they are not taken with an unwarranted precision. More typically, it is therefore reported approximately as: “Guyana’s high forest sequester 13 billion tonnes of carbon dioxide in living trees, or 16 billion tonnes, including necromass and soils.

Nationally, all Guyana’s living ecosystems sequester 18.4 billion tonnes of carbon dioxide”.

Next week I continue the discussion from this observation.

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