Deforestation and forest degradation are the second leading cause of global warming, responsible for about 15 per cent of global greenhouse gas (GHG) emissions. It was with this in mind that the UN-backed Redd+ scheme was devised, to encourage tropical countries to halt and reverse forest loss. Under the scheme, countries submit baseline emission levels and become eligible for payment if they show a drop in emissions in comparison to those submitted levels.

In late February, the Green Climate Fund approved the first payout of $96million to Brazil in return for decreased deforestation in 2014 and 2015 (amounting to a reduction of 19 million tons of GHG emissions). Another 38 countries have submitted their levels and could be eligible for payments in the future.

However, concerns have been raised about the methodology of the scheme, centring on the baseline data submitted by each country. Using publicly available, satellite-based statistics for global forest cover, scientists from the School of Geosciences at the University of Edinburgh have drawn up a comparison with the baseline data submitted by countries in the Asia-Pacific region. Their analysis has found significant differences in the size – and sometimes the direction – of change in forest area for seven countries. Most notably they found that Cambodia and Sri Lanka’s reference levels overstated forest loss, raising the possibility that they could overstate emissions reductions in the future. In Malaysia and Vietnam, country data showed an increase in forest area over the chosen time period, while satellite data indicated that forest area had decreased.

Were forests gained or lost? Changes in country-defined REDD+ forests versus biophysical forests based on satellite data in seven countries between 2000–2010 [Nomura et al., 2019]

While some differences between the data sets are inevitable, partly due to the fact that satellite data takes into account all deforestation, including harvesting, lead scientist Keiko Nomura believes that the wider picture of discrepancy highlights significant issues. One of the biggest problems is that each country is able to define a ‘forest’ using its own methodology. ‘There is a lot of forest still remaining in areas that are not politically considered forests and not counted for REDD+,’ says Nomura.

Another issue involves the inconsistent use of ‘minimum mapping units’. Some countries use one minimum area to define a forest but a larger minimum area to assess deforestation. In Nepal, the minimum area deemed to constitute a forest is 0.5 hectares, but the minimum area for detecting change to forests is 2.25 hectares. ‘If it loses 0.5 hectares of forest it doesn’t count as a loss. That area is still considered forest until that loss becomes equal to or larger than 2.25 hectares,’ explains Nomura. ‘There would be missed forest loss that would not be captured.’ The researchers found that this leakage meant Nepal had lost an additional one million hectares of forest up to 2016 which was not included in its reference levels.

While Nomura doesn’t think that countries are manipulating data on purpose, or with malicious intent, she wants to see better data transparency from national governments and an emphasis on including all at-risk forests. ‘It’s a great political signal to countries that if you protect forests you can still get paid,’ she says. ‘But more data transparency, that would really help.’

This was published in the May 2019 edition of Geographical magazine

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